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Posted to commits@htrace.apache.org by cm...@apache.org on 2015/08/18 21:05:16 UTC

[1/4] incubator-htrace git commit: HTRACE-211. Move htrace-core classes to the org.apache.htrace.core namespace (cmccabe)

Repository: incubator-htrace
Updated Branches:
  refs/heads/master afa0b71a4 -> fd889b659


http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TestCountSampler.java
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diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TestCountSampler.java b/htrace-core/src/test/java/org/apache/htrace/core/TestCountSampler.java
new file mode 100644
index 0000000..e26115d
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TestCountSampler.java
@@ -0,0 +1,41 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestCountSampler {
+
+  @Test
+  public void testNext() {
+    CountSampler half = new CountSampler(HTraceConfiguration.
+        fromKeyValuePairs("sampler.frequency", "2"));
+    CountSampler hundred = new CountSampler(HTraceConfiguration.
+        fromKeyValuePairs("sampler.frequency", "100"));
+    int halfCount = 0;
+    int hundredCount = 0;
+    for (int i = 0; i < 200; i++) {
+      if (half.next())
+        halfCount++;
+      if (hundred.next())
+        hundredCount++;
+    }
+    Assert.assertEquals(2, hundredCount);
+    Assert.assertEquals(100, halfCount);
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TestHTrace.java
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diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TestHTrace.java b/htrace-core/src/test/java/org/apache/htrace/core/TestHTrace.java
new file mode 100644
index 0000000..f1839cb
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TestHTrace.java
@@ -0,0 +1,116 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.io.File;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.htrace.core.TraceGraph.SpansByParent;
+
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+
+public class TestHTrace {
+
+  @Rule
+  public TraceCreator traceCreator = new TraceCreator();
+
+  public static final String SPAN_FILE_FLAG = "spanFile";
+
+  /**
+   * Basic system test of HTrace.
+   *
+   * @throws Exception
+   */
+  @Test
+  public void testHtrace() throws Exception {
+    final int numTraces = 3;
+    String fileName = System.getProperty(SPAN_FILE_FLAG);
+
+    // writes spans to a file if one is provided to maven with
+    // -DspanFile="FILENAME", otherwise writes to standard out.
+    if (fileName != null) {
+      File f = new File(fileName);
+      File parent = f.getParentFile();
+      if (parent != null && !parent.exists() && !parent.mkdirs()) {
+        throw new IllegalArgumentException("Couldn't create file: "
+            + fileName);
+      }
+      HashMap<String, String> conf = new HashMap<String, String>();
+      conf.put("local-file-span-receiver.path", fileName);
+      LocalFileSpanReceiver receiver =
+          new LocalFileSpanReceiver(HTraceConfiguration.fromMap(conf));
+      traceCreator.addReceiver(receiver);
+    } else {
+      traceCreator.addReceiver(new StandardOutSpanReceiver(HTraceConfiguration.EMPTY));
+    }
+
+    traceCreator.addReceiver(new POJOSpanReceiver(HTraceConfiguration.EMPTY){
+      @Override
+      public void close() {
+        TraceGraph traceGraph = new TraceGraph(getSpans());
+        Collection<Span> roots = traceGraph.getSpansByParent().find(SpanId.INVALID);
+        Assert.assertTrue("Trace tree must have roots", !roots.isEmpty());
+        Assert.assertEquals(numTraces, roots.size());
+
+        Map<String, Span> descriptionToRootSpan = new HashMap<String, Span>();
+        for (Span root : roots) {
+          descriptionToRootSpan.put(root.getDescription(), root);
+        }
+
+        Assert.assertTrue(descriptionToRootSpan.keySet().contains(
+            TraceCreator.RPC_TRACE_ROOT));
+        Assert.assertTrue(descriptionToRootSpan.keySet().contains(
+            TraceCreator.SIMPLE_TRACE_ROOT));
+        Assert.assertTrue(descriptionToRootSpan.keySet().contains(
+            TraceCreator.THREADED_TRACE_ROOT));
+
+        SpansByParent spansByParentId = traceGraph.getSpansByParent();
+        Span rpcTraceRoot = descriptionToRootSpan.get(TraceCreator.RPC_TRACE_ROOT);
+        Assert.assertEquals(1, spansByParentId.find(rpcTraceRoot.getSpanId()).size());
+
+        Span rpcTraceChild1 = spansByParentId.find(rpcTraceRoot.getSpanId())
+            .iterator().next();
+        Assert.assertEquals(1, spansByParentId.find(rpcTraceChild1.getSpanId()).size());
+
+        Span rpcTraceChild2 = spansByParentId.find(rpcTraceChild1.getSpanId())
+            .iterator().next();
+        Assert.assertEquals(1, spansByParentId.find(rpcTraceChild2.getSpanId()).size());
+
+        Span rpcTraceChild3 = spansByParentId.find(rpcTraceChild2.getSpanId())
+            .iterator().next();
+        Assert.assertEquals(0, spansByParentId.find(rpcTraceChild3.getSpanId()).size());
+      }
+    });
+
+    traceCreator.createThreadedTrace();
+    traceCreator.createSimpleTrace();
+    traceCreator.createSampleRpcTrace();
+  }
+
+  @Test(timeout=60000)
+  public void testRootSpansHaveNonZeroSpanId() throws Exception {
+    TraceScope scope = Trace.startSpan("myRootSpan", new SpanId(100L, 200L));
+    Assert.assertNotNull(scope);
+    Assert.assertEquals("myRootSpan", scope.getSpan().getDescription());
+    Assert.assertEquals(100L, scope.getSpan().getSpanId().getHigh());
+    Assert.assertTrue(scope.getSpan().getSpanId().isValid());
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TestHTraceConfiguration.java
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diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TestHTraceConfiguration.java b/htrace-core/src/test/java/org/apache/htrace/core/TestHTraceConfiguration.java
new file mode 100644
index 0000000..7ca897f
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TestHTraceConfiguration.java
@@ -0,0 +1,62 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.htrace.core;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.Test;
+
+public class TestHTraceConfiguration {
+  @Test
+  public void testGetBoolean() throws Exception {
+
+    Map<String, String> m = new HashMap<String, String>();
+    m.put("testTrue", " True");
+    m.put("testFalse", "falsE ");
+    HTraceConfiguration configuration = HTraceConfiguration.fromMap(m);
+
+    // Tests for value being there
+    assertTrue(configuration.getBoolean("testTrue", false));
+    assertFalse(configuration.getBoolean("testFalse", true));
+
+    // Test for absent
+    assertTrue(configuration.getBoolean("absent", true));
+    assertFalse(configuration.getBoolean("absent", false));
+  }
+
+  @Test
+  public void testGetInt() throws Exception {
+    Map<String, String> m = new HashMap<String, String>();
+    m.put("a", "100");
+    m.put("b", "0");
+    m.put("c", "-100");
+    m.put("d", "5");
+
+    HTraceConfiguration configuration = HTraceConfiguration.fromMap(m);
+    assertEquals(100, configuration.getInt("a", -999));
+    assertEquals(0, configuration.getInt("b", -999));
+    assertEquals(-100, configuration.getInt("c", -999));
+    assertEquals(5, configuration.getInt("d", -999));
+    assertEquals(-999, configuration.getInt("absent", -999));
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TestLocalFileSpanReceiver.java
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diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TestLocalFileSpanReceiver.java b/htrace-core/src/test/java/org/apache/htrace/core/TestLocalFileSpanReceiver.java
new file mode 100644
index 0000000..90a009a
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TestLocalFileSpanReceiver.java
@@ -0,0 +1,70 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertEquals;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.HashMap;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class TestLocalFileSpanReceiver {
+  @Test
+  public void testUniqueLocalTraceFileName() {
+    String filename1 = LocalFileSpanReceiver.getUniqueLocalTraceFileName();
+    System.out.println("##### :" + filename1);
+    String filename2 = LocalFileSpanReceiver.getUniqueLocalTraceFileName();
+    System.out.println("##### :" + filename2);
+    boolean eq = filename1.equals(filename2);
+    if (System.getProperty("os.name").startsWith("Linux")) {
+      // ${java.io.tmpdir}/[pid]
+      assertTrue(eq);
+    } else {
+      // ${java.io.tmpdir}/[random UUID]
+      assertFalse(eq);
+    }
+  }
+
+  @Test
+  public void testWriteToLocalFile() throws IOException {
+    String traceFileName = LocalFileSpanReceiver.getUniqueLocalTraceFileName();
+    HashMap<String, String> confMap = new HashMap<String, String>();
+    confMap.put(LocalFileSpanReceiver.PATH_KEY, traceFileName);
+    confMap.put(SpanReceiverBuilder.SPAN_RECEIVER_CONF_KEY,
+                LocalFileSpanReceiver.class.getName());
+    confMap.put(TracerId.TRACER_ID_KEY, "testTrid");
+    SpanReceiver rcvr =
+        new SpanReceiverBuilder(HTraceConfiguration.fromMap(confMap))
+            .logErrors(false).build();
+    Trace.addReceiver(rcvr);
+    TraceScope ts = Trace.startSpan("testWriteToLocalFile", Sampler.ALWAYS);
+    ts.close();
+    Trace.removeReceiver(rcvr);
+    rcvr.close();
+
+    ObjectMapper mapper = new ObjectMapper();
+    MilliSpan span = mapper.readValue(new File(traceFileName), MilliSpan.class);
+    assertEquals("testWriteToLocalFile", span.getDescription());
+    assertEquals("testTrid", span.getTracerId());
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TestMilliSpan.java
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diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TestMilliSpan.java b/htrace-core/src/test/java/org/apache/htrace/core/TestMilliSpan.java
new file mode 100644
index 0000000..7ce1fdb
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TestMilliSpan.java
@@ -0,0 +1,145 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+import java.util.concurrent.ThreadLocalRandom;
+
+public class TestMilliSpan {
+  private void compareSpans(Span expected, Span got) throws Exception {
+    assertEquals(expected.getStartTimeMillis(), got.getStartTimeMillis());
+    assertEquals(expected.getStopTimeMillis(), got.getStopTimeMillis());
+    assertEquals(expected.getDescription(), got.getDescription());
+    assertEquals(expected.getSpanId(), got.getSpanId());
+    assertEquals(expected.getTracerId(), got.getTracerId());
+    assertTrue(Arrays.equals(expected.getParents(), got.getParents()));
+    Map<String, String> expectedT = expected.getKVAnnotations();
+    Map<String, String> gotT = got.getKVAnnotations();
+    if (expectedT == null) {
+      assertEquals(null, gotT);
+    } else {
+      assertEquals(expectedT.size(), gotT.size());
+      for (String key : expectedT.keySet()) {
+        assertEquals(expectedT.get(key), gotT.get(key));
+      }
+    }
+    List<TimelineAnnotation> expectedTimeline =
+        expected.getTimelineAnnotations();
+    List<TimelineAnnotation> gotTimeline =
+        got.getTimelineAnnotations();
+    if (expectedTimeline == null) {
+      assertEquals(null, gotTimeline);
+    } else {
+      assertEquals(expectedTimeline.size(), gotTimeline.size());
+      Iterator<TimelineAnnotation> iter = gotTimeline.iterator();
+      for (TimelineAnnotation expectedAnn : expectedTimeline) {
+        TimelineAnnotation gotAnn =  iter.next();
+        assertEquals(expectedAnn.getMessage(), gotAnn.getMessage());
+        assertEquals(expectedAnn.getTime(), gotAnn.getTime());
+      }
+    }
+  }
+
+  @Test
+  public void testJsonSerialization() throws Exception {
+    MilliSpan span = new MilliSpan.Builder().
+        description("foospan").
+        begin(123L).
+        end(456L).
+        parents(new SpanId[] { new SpanId(7L, 7L) }).
+        tracerId("b2404.halxg.com:8080").
+        spanId(new SpanId(7L, 8L)).
+        build();
+    String json = span.toJson();
+    MilliSpan dspan = MilliSpan.fromJson(json);
+    compareSpans(span, dspan);
+  }
+
+  @Test
+  public void testJsonSerializationWithNegativeLongValue() throws Exception {
+    MilliSpan span = new MilliSpan.Builder().
+        description("foospan").
+        begin(-1L).
+        end(-1L).
+        parents(new SpanId[] { new SpanId(-1L, -1L) }).
+        tracerId("b2404.halxg.com:8080").
+        spanId(new SpanId(-1L, -2L)).
+        build();
+    String json = span.toJson();
+    MilliSpan dspan = MilliSpan.fromJson(json);
+    compareSpans(span, dspan);
+  }
+
+  @Test
+  public void testJsonSerializationWithRandomLongValue() throws Exception {
+    SpanId parentId = SpanId.fromRandom();
+    MilliSpan span = new MilliSpan.Builder().
+        description("foospan").
+        begin(ThreadLocalRandom.current().nextLong()).
+        end(ThreadLocalRandom.current().nextLong()).
+        parents(new SpanId[] { parentId }).
+        tracerId("b2404.halxg.com:8080").
+        spanId(parentId.newChildId()).
+        build();
+    String json = span.toJson();
+    MilliSpan dspan = MilliSpan.fromJson(json);
+    compareSpans(span, dspan);
+  }
+
+  @Test
+  public void testJsonSerializationWithOptionalFields() throws Exception {
+    MilliSpan.Builder builder = new MilliSpan.Builder().
+        description("foospan").
+        begin(300).
+        end(400).
+        parents(new SpanId[] { }).
+        tracerId("b2408.halxg.com:8080").
+        spanId(new SpanId(111111111L, 111111111L));
+    Map<String, String> traceInfo = new HashMap<String, String>();
+    traceInfo.put("abc", "123");
+    traceInfo.put("def", "456");
+    builder.traceInfo(traceInfo);
+    List<TimelineAnnotation> timeline = new LinkedList<TimelineAnnotation>();
+    timeline.add(new TimelineAnnotation(310L, "something happened"));
+    timeline.add(new TimelineAnnotation(380L, "something else happened"));
+    timeline.add(new TimelineAnnotation(390L, "more things"));
+    builder.timeline(timeline);
+    MilliSpan span = builder.build();
+    String json = span.toJson();
+    MilliSpan dspan = MilliSpan.fromJson(json);
+    compareSpans(span, dspan);
+  }
+
+  @Test
+  public void testJsonSerializationWithFieldsNotSet() throws Exception {
+    MilliSpan span = new MilliSpan.Builder().build();
+    String json = span.toJson();
+    MilliSpan dspan = MilliSpan.fromJson(json);
+    compareSpans(span, dspan);
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TestNullScope.java
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diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TestNullScope.java b/htrace-core/src/test/java/org/apache/htrace/core/TestNullScope.java
new file mode 100644
index 0000000..3fa9210
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TestNullScope.java
@@ -0,0 +1,34 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestNullScope {
+  @Test
+  public void testNullScope() {
+    Assert.assertTrue(!Trace.isTracing());
+    TraceScope tc = Trace.startSpan("NullScopeSingleton");
+    Assert.assertTrue(tc == NullScope.INSTANCE);
+    tc.detach();
+    tc.detach(); // should not fail even if called multiple times.
+    Assert.assertFalse(tc.isDetached());
+    tc.close();
+    tc.close(); // should not fail even if called multiple times.
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TestSampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TestSampler.java b/htrace-core/src/test/java/org/apache/htrace/core/TestSampler.java
new file mode 100644
index 0000000..e11799b
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TestSampler.java
@@ -0,0 +1,55 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestSampler {
+  @Test
+  public void testSamplerBuilder() {
+    Sampler alwaysSampler = new SamplerBuilder(
+        HTraceConfiguration.fromKeyValuePairs("sampler", "AlwaysSampler")).
+        build();
+    Assert.assertEquals(AlwaysSampler.class, alwaysSampler.getClass());
+
+    Sampler neverSampler = new SamplerBuilder(
+        HTraceConfiguration.fromKeyValuePairs("sampler", "NeverSampler")).
+        build();
+    Assert.assertEquals(NeverSampler.class, neverSampler.getClass());
+
+    Sampler neverSampler2 = new SamplerBuilder(HTraceConfiguration.
+        fromKeyValuePairs("sampler", "NonExistentSampler")).
+        build();
+    Assert.assertEquals(NeverSampler.class, neverSampler2.getClass());
+
+    Sampler neverSampler3 = new SamplerBuilder(HTraceConfiguration.
+        fromKeyValuePairs("sampler.is.not.defined", "NonExistentSampler")).
+        build();
+    Assert.assertEquals(NeverSampler.class, neverSampler3.getClass());
+  }
+
+  @Test
+  public void testAlwaysSampler() {
+    TraceScope cur = Trace.startSpan("test");
+    Assert.assertNotNull(cur);
+    cur.close();
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TestSpanId.java
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diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TestSpanId.java b/htrace-core/src/test/java/org/apache/htrace/core/TestSpanId.java
new file mode 100644
index 0000000..bb57368
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TestSpanId.java
@@ -0,0 +1,72 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.util.Random;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestSpanId {
+  private void testRoundTrip(SpanId id) throws Exception {
+    String str = id.toString();
+    SpanId id2 = SpanId.fromString(str);
+    Assert.assertEquals(id, id2);
+  }
+
+  @Test
+  public void testToStringAndFromString() throws Exception {
+    testRoundTrip(SpanId.INVALID);
+    testRoundTrip(new SpanId(0x1234567812345678L, 0x1234567812345678L));
+    testRoundTrip(new SpanId(0xf234567812345678L, 0xf234567812345678L));
+    testRoundTrip(new SpanId(0xffffffffffffffffL, 0xffffffffffffffffL));
+    Random rand = new Random(12345);
+    for (int i = 0; i < 100; i++) {
+      testRoundTrip(new SpanId(rand.nextLong(), rand.nextLong()));
+    }
+  }
+
+  @Test
+  public void testValidAndInvalidIds() throws Exception {
+    Assert.assertFalse(SpanId.INVALID.isValid());
+    Assert.assertTrue(
+        new SpanId(0x1234567812345678L, 0x1234567812345678L).isValid());
+    Assert.assertTrue(
+        new SpanId(0xf234567812345678L, 0xf234567812345678L).isValid());
+  }
+
+  private void expectLessThan(SpanId a, SpanId b) throws Exception {
+    int cmp = a.compareTo(b);
+    Assert.assertTrue("Expected " + a + " to be less than " + b,
+        (cmp < 0));
+    int cmp2 = b.compareTo(a);
+    Assert.assertTrue("Expected " + b + " to be greater than " + a,
+        (cmp2 > 0));
+  }
+
+  @Test
+  public void testIdComparisons() throws Exception {
+    expectLessThan(new SpanId(0x0000000000000001L, 0x0000000000000001L),
+                   new SpanId(0x0000000000000001L, 0x0000000000000002L));
+    expectLessThan(new SpanId(0x0000000000000001L, 0x0000000000000001L),
+                   new SpanId(0x0000000000000002L, 0x0000000000000000L));
+    expectLessThan(SpanId.INVALID,
+                   new SpanId(0xffffffffffffffffL, 0xffffffffffffffffL));
+    expectLessThan(new SpanId(0x1234567812345678L, 0x1234567812345678L),
+                   new SpanId(0x1234567812345678L, 0xf234567812345678L));
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TestSpanReceiverBuilder.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TestSpanReceiverBuilder.java b/htrace-core/src/test/java/org/apache/htrace/core/TestSpanReceiverBuilder.java
new file mode 100644
index 0000000..79795e4
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TestSpanReceiverBuilder.java
@@ -0,0 +1,139 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestSpanReceiverBuilder {
+  private static final Log LOG =
+      LogFactory.getLog(TestSpanReceiverBuilder.class);
+
+  /**
+   * Test that if no span receiver is configured, the builder returns null.
+   */
+  @Test
+  public void testGetNullSpanReceiver() {
+    SpanReceiverBuilder builder =
+        new SpanReceiverBuilder(HTraceConfiguration.EMPTY).logErrors(false);
+    SpanReceiver rcvr = builder.build();
+    Assert.assertEquals(null, rcvr);
+  }
+
+  private static SpanReceiver createSpanReceiver(Map<String, String> m) {
+    HTraceConfiguration hconf = HTraceConfiguration.fromMap(m);
+    SpanReceiverBuilder builder =
+        new SpanReceiverBuilder(hconf).
+            logErrors(false);
+    return builder.build();
+  }
+
+  private static final File TMPDIR =
+      new File(System.getProperty("java.io.tmpdir"));
+
+  /**
+   * Test getting various SpanReceiver objects.
+   */
+  @Test
+  public void testGetSpanReceivers() throws Exception {
+    HashMap<String, String> confMap = new HashMap<String, String>();
+
+    // Create LocalFileSpanReceiver
+    File testFile = new File(TMPDIR, UUID.randomUUID().toString());
+    try {
+      confMap.put(LocalFileSpanReceiver.PATH_KEY, testFile.getAbsolutePath());
+      confMap.put(SpanReceiverBuilder.SPAN_RECEIVER_CONF_KEY,
+          "org.apache.htrace.core.LocalFileSpanReceiver");
+      SpanReceiver rcvr = createSpanReceiver(confMap);
+      Assert.assertNotNull(rcvr);
+      Assert.assertEquals("org.apache.htrace.core.LocalFileSpanReceiver",
+          rcvr.getClass().getName());
+      rcvr.close();
+    } finally {
+      if (!testFile.delete()) {
+        LOG.debug("failed to delete " + testFile); // keep findbugs happy
+      }
+    }
+
+    // Create POJOSpanReceiver
+    confMap.remove(LocalFileSpanReceiver.PATH_KEY);
+    confMap.put(SpanReceiverBuilder.SPAN_RECEIVER_CONF_KEY, "POJOSpanReceiver");
+    SpanReceiver rcvr = createSpanReceiver(confMap);
+    Assert.assertEquals("org.apache.htrace.core.POJOSpanReceiver",
+        rcvr.getClass().getName());
+    rcvr.close();
+
+    // Create StandardOutSpanReceiver
+    confMap.remove(LocalFileSpanReceiver.PATH_KEY);
+    confMap.put(SpanReceiverBuilder.SPAN_RECEIVER_CONF_KEY,
+        "org.apache.htrace.core.StandardOutSpanReceiver");
+    rcvr = createSpanReceiver(confMap);
+    Assert.assertEquals("org.apache.htrace.core.StandardOutSpanReceiver",
+        rcvr.getClass().getName());
+    rcvr.close();
+  }
+
+  public static class TestSpanReceiver implements SpanReceiver {
+    final static String SUCCEEDS = "test.span.receiver.succeeds";
+
+    public TestSpanReceiver(HTraceConfiguration conf) {
+      if (conf.get(SUCCEEDS) == null) {
+        throw new RuntimeException("Can't create TestSpanReceiver: " +
+            "invalid configuration.");
+      }
+    }
+
+    @Override
+    public void receiveSpan(Span span) {
+    }
+
+    @Override
+    public void close() throws IOException {
+    }
+  }
+
+  /**
+   * Test trying to create a SpanReceiver that experiences an error in the
+   * constructor.
+   */
+  @Test
+  public void testGetSpanReceiverWithConstructorError() throws Exception {
+    HashMap<String, String> confMap = new HashMap<String, String>();
+
+    // Create TestSpanReceiver
+    confMap.put(SpanReceiverBuilder.SPAN_RECEIVER_CONF_KEY,
+        TestSpanReceiver.class.getName());
+    confMap.put(TestSpanReceiver.SUCCEEDS, "true");
+    SpanReceiver rcvr = createSpanReceiver(confMap);
+    Assert.assertEquals(TestSpanReceiver.class.getName(),
+        rcvr.getClass().getName());
+    rcvr.close();
+
+    // Fail to create TestSpanReceiver
+    confMap.remove(TestSpanReceiver.SUCCEEDS);
+    rcvr = createSpanReceiver(confMap);
+    Assert.assertEquals(null, rcvr);
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TestTracerId.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TestTracerId.java b/htrace-core/src/test/java/org/apache/htrace/core/TestTracerId.java
new file mode 100644
index 0000000..ac43653
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TestTracerId.java
@@ -0,0 +1,47 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.io.IOException;
+import org.junit.Test;
+import static org.junit.Assert.assertEquals;
+
+public class TestTracerId {
+  private void testTracerIdImpl(String expected, String fmt) {
+    assertEquals(expected, new TracerId(fmt).get());
+  }
+
+  @Test
+  public void testSimpleTracerIds() {
+    testTracerIdImpl("abc", "abc");
+    testTracerIdImpl("abc", "a\\bc");
+    testTracerIdImpl("abc", "ab\\c");
+    testTracerIdImpl("abc", "\\a\\b\\c");
+    testTracerIdImpl("a\\bc", "a\\\\bc");
+  }
+
+  @Test
+  public void testSubstitutionVariables() throws IOException {
+    testTracerIdImpl(TracerId.getProcessName(), "${pname}");
+    testTracerIdImpl("my." + TracerId.getProcessName(), "my.${pname}");
+    testTracerIdImpl(TracerId.getBestIpString() + ".str", "${ip}.str");
+    testTracerIdImpl("${pname}", "\\${pname}");
+    testTracerIdImpl("$cash$money{}", "$cash$money{}");
+    testTracerIdImpl("Foo." + Long.valueOf(TracerId.getOsPid()).toString(),
+        "Foo.${pid}");
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TraceCreator.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TraceCreator.java b/htrace-core/src/test/java/org/apache/htrace/core/TraceCreator.java
new file mode 100644
index 0000000..f6ae97f
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TraceCreator.java
@@ -0,0 +1,169 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+import java.util.Collection;
+import java.util.Random;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+
+/**
+ * Does some stuff and traces it.
+ */
+public class TraceCreator implements TestRule {
+  private final List<SpanReceiver> receivers = new ArrayList<SpanReceiver>();
+
+  public static final String RPC_TRACE_ROOT = "createSampleRpcTrace";
+  public static final String THREADED_TRACE_ROOT = "createThreadedTrace";
+  public static final String SIMPLE_TRACE_ROOT = "createSimpleTrace";
+
+  public TraceCreator addReceiver(SpanReceiver receiver) {
+    Trace.addReceiver(receiver);
+    this.receivers.add(receiver);
+    return this;
+  }
+
+  @Override
+  public Statement apply(final Statement base, Description description) {
+    return new Statement() {
+      @Override
+      public void evaluate() throws Throwable {
+        try {
+          base.evaluate();
+          for (SpanReceiver receiver : receivers) {
+            receiver.close();
+          }
+        } finally {
+          for (SpanReceiver receiver : receivers) {
+            Trace.removeReceiver(receiver);
+          }
+        }
+      }
+    };
+  }
+
+  public void createSampleRpcTrace() {
+    TraceScope s = Trace.startSpan(RPC_TRACE_ROOT, Sampler.ALWAYS);
+    try {
+      pretendRpcSend();
+    } finally {
+      s.close();
+    }
+  }
+
+  public void createSimpleTrace() {
+    TraceScope s = Trace.startSpan(SIMPLE_TRACE_ROOT, Sampler.ALWAYS);
+    try {
+      importantWork1();
+    } finally {
+      s.close();
+    }
+  }
+
+  /**
+   * Creates the demo trace (will create different traces from call to call).
+   */
+  public void createThreadedTrace() {
+    TraceScope s = Trace.startSpan(THREADED_TRACE_ROOT, Sampler.ALWAYS);
+    try {
+      Random r = ThreadLocalRandom.current();
+      int numThreads = r.nextInt(4) + 1;
+      Thread[] threads = new Thread[numThreads];
+
+      for (int i = 0; i < numThreads; i++) {
+        threads[i] = new Thread(Trace.wrap(new MyRunnable()));
+      }
+      for (int i = 0; i < numThreads; i++) {
+        threads[i].start();
+      }
+      for (int i = 0; i < numThreads; i++) {
+        try {
+          threads[i].join();
+        } catch (InterruptedException e) {
+        }
+      }
+      importantWork1();
+    } finally {
+      s.close();
+    }
+  }
+
+  private void importantWork1() {
+    TraceScope cur = Trace.startSpan("important work 1");
+    try {
+      Thread.sleep((long) (2000 * Math.random()));
+      importantWork2();
+    } catch (InterruptedException e) {
+      Thread.currentThread().interrupt();
+    } finally {
+      cur.close();
+    }
+  }
+
+  private void importantWork2() {
+    TraceScope cur = Trace.startSpan("important work 2");
+    try {
+      Thread.sleep((long) (2000 * Math.random()));
+    } catch (InterruptedException e) {
+      Thread.currentThread().interrupt();
+    } finally {
+      cur.close();
+    }
+  }
+
+  private class MyRunnable implements Runnable {
+    @Override
+    public void run() {
+      try {
+        Thread.sleep(750);
+        Random r = ThreadLocalRandom.current();
+        int importantNumber = 100 / r.nextInt(3);
+        System.out.println("Important number: " + importantNumber);
+      } catch (InterruptedException ie) {
+        Thread.currentThread().interrupt();
+      } catch (ArithmeticException ae) {
+        TraceScope c = Trace.startSpan("dealing with arithmetic exception.");
+        try {
+          Thread.sleep((long) (3000 * Math.random()));
+        } catch (InterruptedException ie1) {
+          Thread.currentThread().interrupt();
+        } finally {
+          c.close();
+        }
+      }
+    }
+  }
+
+  public void pretendRpcSend() {
+    pretendRpcReceiveWithTraceInfo(Trace.currentSpan());
+  }
+
+  public void pretendRpcReceiveWithTraceInfo(Span parent) {
+    TraceScope s = Trace.startSpan("received RPC", parent);
+    try {
+      importantWork1();
+    } finally {
+      s.close();
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TraceGraph.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TraceGraph.java b/htrace-core/src/test/java/org/apache/htrace/core/TraceGraph.java
new file mode 100644
index 0000000..a06e620
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TraceGraph.java
@@ -0,0 +1,176 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.TreeSet;
+
+/**
+ * Used to create the graph formed by spans.
+ */
+public class TraceGraph {
+  private static final Log LOG = LogFactory.getLog(Tracer.class);
+
+
+  public static class SpansByParent {
+    /**
+     * Compare two spans by span ID.
+     */
+    private static Comparator<Span> COMPARATOR =
+        new Comparator<Span>() {
+          @Override
+          public int compare(Span a, Span b) {
+            return a.getSpanId().compareTo(b.getSpanId());
+          }
+        };
+
+    private final TreeSet<Span> treeSet;
+
+    private final HashMap<SpanId, LinkedList<Span>> parentToSpans;
+
+    SpansByParent(Collection<Span> spans) {
+      TreeSet<Span> treeSet = new TreeSet<Span>(COMPARATOR);
+      parentToSpans = new HashMap<SpanId, LinkedList<Span>>();
+      for (Span span : spans) {
+        treeSet.add(span);
+        for (SpanId parent : span.getParents()) {
+          LinkedList<Span> list = parentToSpans.get(parent);
+          if (list == null) {
+            list = new LinkedList<Span>();
+            parentToSpans.put(parent, list);
+          }
+          list.add(span);
+        }
+        if (span.getParents().length == 0) {
+          LinkedList<Span> list = parentToSpans.get(SpanId.INVALID);
+          if (list == null) {
+            list = new LinkedList<Span>();
+            parentToSpans.put(SpanId.INVALID, list);
+          }
+          list.add(span);
+        }
+      }
+      this.treeSet = treeSet;
+    }
+
+    public List<Span> find(SpanId parentId) {
+      LinkedList<Span> spans = parentToSpans.get(parentId);
+      if (spans == null) {
+        return new LinkedList<Span>();
+      }
+      return spans;
+    }
+
+    public Iterator<Span> iterator() {
+      return Collections.unmodifiableSortedSet(treeSet).iterator();
+    }
+  }
+
+  public static class SpansByTracerId {
+    /**
+     * Compare two spans by process ID, and then by span ID.
+     */
+    private static Comparator<Span> COMPARATOR =
+        new Comparator<Span>() {
+          @Override
+          public int compare(Span a, Span b) {
+            int cmp = a.getTracerId().compareTo(b.getTracerId());
+            if (cmp != 0) {
+              return cmp;
+            }
+            return a.getSpanId().compareTo(b.getSpanId());
+          }
+        };
+
+    private final TreeSet<Span> treeSet;
+
+    SpansByTracerId(Collection<Span> spans) {
+      TreeSet<Span> treeSet = new TreeSet<Span>(COMPARATOR);
+      for (Span span : spans) {
+        treeSet.add(span);
+      }
+      this.treeSet = treeSet;
+    }
+
+    public List<Span> find(String tracerId) {
+      List<Span> spans = new ArrayList<Span>();
+      Span span = new MilliSpan.Builder().
+                    spanId(SpanId.INVALID).
+                    tracerId(tracerId).
+                    build();
+      while (true) {
+        span = treeSet.higher(span);
+        if (span == null) {
+          break;
+        }
+        if (span.getTracerId().equals(tracerId)) {
+          break;
+        }
+        spans.add(span);
+      }
+      return spans;
+    }
+
+    public Iterator<Span> iterator() {
+      return Collections.unmodifiableSortedSet(treeSet).iterator();
+    }
+  }
+
+  private final SpansByParent spansByParent;
+  private final SpansByTracerId spansByTracerId;
+
+  /**
+   * Create a new TraceGraph
+   *
+   * @param spans The collection of spans to use to create this TraceGraph. Should
+   *              have at least one root span.
+   */
+  public TraceGraph(Collection<Span> spans) {
+    this.spansByParent = new SpansByParent(spans);
+    this.spansByTracerId = new SpansByTracerId(spans);
+  }
+
+  public SpansByParent getSpansByParent() {
+    return spansByParent;
+  }
+
+  public SpansByTracerId getSpansByTracerId() {
+    return spansByTracerId;
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder bld = new StringBuilder();
+    String prefix = "";
+    for (Iterator<Span> iter = spansByParent.iterator(); iter.hasNext();) {
+      Span span = iter.next();
+      bld.append(prefix).append(span.toString());
+      prefix = "\n";
+    }
+    return bld.toString();
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/impl/TestLocalFileSpanReceiver.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/impl/TestLocalFileSpanReceiver.java b/htrace-core/src/test/java/org/apache/htrace/impl/TestLocalFileSpanReceiver.java
deleted file mode 100644
index 311ddc6..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/impl/TestLocalFileSpanReceiver.java
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import com.fasterxml.jackson.databind.ObjectMapper;
-import java.io.File;
-import java.io.IOException;
-import java.util.HashMap;
-import org.apache.htrace.HTraceConfiguration;
-import org.apache.htrace.Sampler;
-import org.apache.htrace.Span;
-import org.apache.htrace.SpanReceiver;
-import org.apache.htrace.SpanReceiverBuilder;
-import org.apache.htrace.Trace;
-import org.apache.htrace.TraceScope;
-import org.junit.Ignore;
-import org.junit.Test;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertEquals;
-
-public class TestLocalFileSpanReceiver {
-  @Test
-  public void testUniqueLocalTraceFileName() {
-    String filename1 = LocalFileSpanReceiver.getUniqueLocalTraceFileName();
-    System.out.println("##### :" + filename1);
-    String filename2 = LocalFileSpanReceiver.getUniqueLocalTraceFileName();
-    System.out.println("##### :" + filename2);
-    boolean eq = filename1.equals(filename2);
-    if (System.getProperty("os.name").startsWith("Linux")) {
-      // ${java.io.tmpdir}/[pid]
-      assertTrue(eq);
-    } else {
-      // ${java.io.tmpdir}/[random UUID]
-      assertFalse(eq);
-    }
-  }
-
-  @Test
-  public void testWriteToLocalFile() throws IOException {
-    String traceFileName = LocalFileSpanReceiver.getUniqueLocalTraceFileName();
-    HashMap<String, String> confMap = new HashMap<String, String>();
-    confMap.put(LocalFileSpanReceiver.PATH_KEY, traceFileName);
-    confMap.put(SpanReceiverBuilder.SPAN_RECEIVER_CONF_KEY,
-                LocalFileSpanReceiver.class.getName());
-    confMap.put(TracerId.TRACER_ID_KEY, "testTrid");
-    SpanReceiver rcvr =
-        new SpanReceiverBuilder(HTraceConfiguration.fromMap(confMap))
-            .logErrors(false).build();
-    Trace.addReceiver(rcvr);
-    TraceScope ts = Trace.startSpan("testWriteToLocalFile", Sampler.ALWAYS);
-    ts.close();
-    Trace.removeReceiver(rcvr);
-    rcvr.close();
-
-    ObjectMapper mapper = new ObjectMapper();
-    MilliSpan span = mapper.readValue(new File(traceFileName), MilliSpan.class);
-    assertEquals("testWriteToLocalFile", span.getDescription());
-    assertEquals("testTrid", span.getTracerId());
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/impl/TestMilliSpan.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/impl/TestMilliSpan.java b/htrace-core/src/test/java/org/apache/htrace/impl/TestMilliSpan.java
deleted file mode 100644
index 9a0be4a..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/impl/TestMilliSpan.java
+++ /dev/null
@@ -1,148 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-
-import org.apache.htrace.Span;
-import org.apache.htrace.SpanId;
-import org.apache.htrace.TimelineAnnotation;
-import org.junit.Test;
-
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
-import java.util.Random;
-import java.util.concurrent.ThreadLocalRandom;
-
-public class TestMilliSpan {
-  private void compareSpans(Span expected, Span got) throws Exception {
-    assertEquals(expected.getStartTimeMillis(), got.getStartTimeMillis());
-    assertEquals(expected.getStopTimeMillis(), got.getStopTimeMillis());
-    assertEquals(expected.getDescription(), got.getDescription());
-    assertEquals(expected.getSpanId(), got.getSpanId());
-    assertEquals(expected.getTracerId(), got.getTracerId());
-    assertTrue(Arrays.equals(expected.getParents(), got.getParents()));
-    Map<String, String> expectedT = expected.getKVAnnotations();
-    Map<String, String> gotT = got.getKVAnnotations();
-    if (expectedT == null) {
-      assertEquals(null, gotT);
-    } else {
-      assertEquals(expectedT.size(), gotT.size());
-      for (String key : expectedT.keySet()) {
-        assertEquals(expectedT.get(key), gotT.get(key));
-      }
-    }
-    List<TimelineAnnotation> expectedTimeline =
-        expected.getTimelineAnnotations();
-    List<TimelineAnnotation> gotTimeline =
-        got.getTimelineAnnotations();
-    if (expectedTimeline == null) {
-      assertEquals(null, gotTimeline);
-    } else {
-      assertEquals(expectedTimeline.size(), gotTimeline.size());
-      Iterator<TimelineAnnotation> iter = gotTimeline.iterator();
-      for (TimelineAnnotation expectedAnn : expectedTimeline) {
-        TimelineAnnotation gotAnn =  iter.next();
-        assertEquals(expectedAnn.getMessage(), gotAnn.getMessage());
-        assertEquals(expectedAnn.getTime(), gotAnn.getTime());
-      }
-    }
-  }
-
-  @Test
-  public void testJsonSerialization() throws Exception {
-    MilliSpan span = new MilliSpan.Builder().
-        description("foospan").
-        begin(123L).
-        end(456L).
-        parents(new SpanId[] { new SpanId(7L, 7L) }).
-        tracerId("b2404.halxg.com:8080").
-        spanId(new SpanId(7L, 8L)).
-        build();
-    String json = span.toJson();
-    MilliSpan dspan = MilliSpan.fromJson(json);
-    compareSpans(span, dspan);
-  }
-
-  @Test
-  public void testJsonSerializationWithNegativeLongValue() throws Exception {
-    MilliSpan span = new MilliSpan.Builder().
-        description("foospan").
-        begin(-1L).
-        end(-1L).
-        parents(new SpanId[] { new SpanId(-1L, -1L) }).
-        tracerId("b2404.halxg.com:8080").
-        spanId(new SpanId(-1L, -2L)).
-        build();
-    String json = span.toJson();
-    MilliSpan dspan = MilliSpan.fromJson(json);
-    compareSpans(span, dspan);
-  }
-
-  @Test
-  public void testJsonSerializationWithRandomLongValue() throws Exception {
-    SpanId parentId = SpanId.fromRandom();
-    MilliSpan span = new MilliSpan.Builder().
-        description("foospan").
-        begin(ThreadLocalRandom.current().nextLong()).
-        end(ThreadLocalRandom.current().nextLong()).
-        parents(new SpanId[] { parentId }).
-        tracerId("b2404.halxg.com:8080").
-        spanId(parentId.newChildId()).
-        build();
-    String json = span.toJson();
-    MilliSpan dspan = MilliSpan.fromJson(json);
-    compareSpans(span, dspan);
-  }
-
-  @Test
-  public void testJsonSerializationWithOptionalFields() throws Exception {
-    MilliSpan.Builder builder = new MilliSpan.Builder().
-        description("foospan").
-        begin(300).
-        end(400).
-        parents(new SpanId[] { }).
-        tracerId("b2408.halxg.com:8080").
-        spanId(new SpanId(111111111L, 111111111L));
-    Map<String, String> traceInfo = new HashMap<String, String>();
-    traceInfo.put("abc", "123");
-    traceInfo.put("def", "456");
-    builder.traceInfo(traceInfo);
-    List<TimelineAnnotation> timeline = new LinkedList<TimelineAnnotation>();
-    timeline.add(new TimelineAnnotation(310L, "something happened"));
-    timeline.add(new TimelineAnnotation(380L, "something else happened"));
-    timeline.add(new TimelineAnnotation(390L, "more things"));
-    builder.timeline(timeline);
-    MilliSpan span = builder.build();
-    String json = span.toJson();
-    MilliSpan dspan = MilliSpan.fromJson(json);
-    compareSpans(span, dspan);
-  }
-
-  @Test
-  public void testJsonSerializationWithFieldsNotSet() throws Exception {
-    MilliSpan span = new MilliSpan.Builder().build();
-    String json = span.toJson();
-    MilliSpan dspan = MilliSpan.fromJson(json);
-    compareSpans(span, dspan);
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/impl/TestTracerId.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/impl/TestTracerId.java b/htrace-core/src/test/java/org/apache/htrace/impl/TestTracerId.java
deleted file mode 100644
index 271d082..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/impl/TestTracerId.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import java.io.IOException;
-import org.junit.Test;
-import static org.junit.Assert.assertEquals;
-
-public class TestTracerId {
-  private void testTracerIdImpl(String expected, String fmt) {
-    assertEquals(expected, new TracerId(fmt).get());
-  }
-
-  @Test
-  public void testSimpleTracerIds() {
-    testTracerIdImpl("abc", "abc");
-    testTracerIdImpl("abc", "a\\bc");
-    testTracerIdImpl("abc", "ab\\c");
-    testTracerIdImpl("abc", "\\a\\b\\c");
-    testTracerIdImpl("a\\bc", "a\\\\bc");
-  }
-
-  @Test
-  public void testSubstitutionVariables() throws IOException {
-    testTracerIdImpl(TracerId.getProcessName(), "${pname}");
-    testTracerIdImpl("my." + TracerId.getProcessName(), "my.${pname}");
-    testTracerIdImpl(TracerId.getBestIpString() + ".str", "${ip}.str");
-    testTracerIdImpl("${pname}", "\\${pname}");
-    testTracerIdImpl("$cash$money{}", "$cash$money{}");
-    testTracerIdImpl("Foo." + Long.valueOf(TracerId.getOsPid()).toString(),
-        "Foo.${pid}");
-  }
-}


[3/4] incubator-htrace git commit: HTRACE-211. Move htrace-core classes to the org.apache.htrace.core namespace (cmccabe)

Posted by cm...@apache.org.
http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/Sampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/Sampler.java b/htrace-core/src/main/java/org/apache/htrace/core/Sampler.java
new file mode 100644
index 0000000..91843f5
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/Sampler.java
@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+/**
+ * Extremely simple callback to determine the frequency that an action should be
+ * performed.
+ * <p/>
+ * For example, the next() function may look like this:
+ * <p/>
+ * <pre>
+ * <code>
+ * public boolean next() {
+ *   return Math.random() &gt; 0.5;
+ * }
+ * </code>
+ * </pre>
+ * This would trace 50% of all gets, 75% of all puts and would not trace any other requests.
+ */
+public interface Sampler {
+  public static final Sampler ALWAYS = AlwaysSampler.INSTANCE;
+  public static final Sampler NEVER = NeverSampler.INSTANCE;
+
+  public boolean next();
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/SamplerBuilder.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/SamplerBuilder.java b/htrace-core/src/main/java/org/apache/htrace/core/SamplerBuilder.java
new file mode 100644
index 0000000..5b53905
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/SamplerBuilder.java
@@ -0,0 +1,91 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.lang.reflect.Constructor;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * A {@link Sampler} builder. It reads a {@link Sampler} class name from the provided
+ * configuration using the {@link #SAMPLER_CONF_KEY} key. Unqualified class names
+ * are interpreted as members of the {@code org.apache.htrace.impl} package. The {@link #build()}
+ * method constructs an instance of that class, initialized with the same configuration.
+ */
+public class SamplerBuilder {
+
+  // TODO: should follow the same API as SpanReceiverBuilder
+
+  public final static String SAMPLER_CONF_KEY = "sampler";
+  private final static String DEFAULT_PACKAGE = "org.apache.htrace.core";
+  private final static ClassLoader classLoader =
+      SamplerBuilder.class.getClassLoader();
+  private final HTraceConfiguration conf;
+  private static final Log LOG = LogFactory.getLog(SamplerBuilder.class);
+
+  public SamplerBuilder(HTraceConfiguration conf) {
+    this.conf = conf;
+  }
+
+  public Sampler build() {
+    Sampler sampler = newSampler();
+    if (LOG.isTraceEnabled()) {
+      LOG.trace("Created new sampler of type " +
+          sampler.getClass().getName(), new Exception());
+    }
+    return sampler;
+  }
+
+  private Sampler newSampler() {
+    String str = conf.get(SAMPLER_CONF_KEY);
+    if (str == null || str.isEmpty()) {
+      return NeverSampler.INSTANCE;
+    }
+    if (!str.contains(".")) {
+      str = DEFAULT_PACKAGE + "." + str;
+    }
+    Class cls = null;
+    try {
+      cls = classLoader.loadClass(str);
+    } catch (ClassNotFoundException e) {
+      LOG.error("SamplerBuilder cannot find sampler class " + str +
+          ": falling back on NeverSampler.");
+      return NeverSampler.INSTANCE;
+    }
+    Constructor<Sampler> ctor = null;
+    try {
+      ctor = cls.getConstructor(HTraceConfiguration.class);
+    } catch (NoSuchMethodException e) {
+      LOG.error("SamplerBuilder cannot find a constructor for class " + str +
+          "which takes an HTraceConfiguration.  Falling back on " +
+          "NeverSampler.");
+      return NeverSampler.INSTANCE;
+    }
+    try {
+      return ctor.newInstance(conf);
+    } catch (ReflectiveOperationException e) {
+      LOG.error("SamplerBuilder reflection error when constructing " + str +
+          ".  Falling back on NeverSampler.", e);
+      return NeverSampler.INSTANCE;
+    } catch (Throwable e) {
+      LOG.error("SamplerBuilder constructor error when constructing " + str +
+          ".  Falling back on NeverSampler.", e);
+      return NeverSampler.INSTANCE;
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/Span.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/Span.java b/htrace-core/src/main/java/org/apache/htrace/core/Span.java
new file mode 100644
index 0000000..db1a961
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/Span.java
@@ -0,0 +1,192 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+
+
+/**
+ * Base interface for gathering and reporting statistics about a block of
+ * execution.
+ * <p/>
+ * Spans should form a directed acyclic graph structure.  It should be possible
+ * to keep following the parents of a span until you arrive at a span with no
+ * parents.<p/>
+ */
+@JsonSerialize(using = Span.SpanSerializer.class)
+public interface Span {
+  /**
+   * The block has completed, stop the clock
+   */
+  void stop();
+
+  /**
+   * Get the start time, in milliseconds
+   */
+  long getStartTimeMillis();
+
+  /**
+   * Get the stop time, in milliseconds
+   */
+  long getStopTimeMillis();
+
+  /**
+   * Return the total amount of time elapsed since start was called, if running,
+   * or difference between stop and start
+   */
+  long getAccumulatedMillis();
+
+  /**
+   * Has the span been started and not yet stopped?
+   */
+  boolean isRunning();
+
+  /**
+   * Return a textual description of this span.<p/>
+   *
+   * Will never be null.
+   */
+  String getDescription();
+
+  /**
+   * A pseudo-unique (random) number assigned to this span instance.<p/>
+   *
+   * The spanId is immutable and cannot be changed.  It is safe to access this
+   * from multiple threads.
+   */
+  SpanId getSpanId();
+
+  /**
+   * Create a child span of this span with the given description
+   */
+  Span child(String description);
+
+  @Override
+  String toString();
+
+  /**
+   * Returns the parent IDs of the span.<p/>
+   *
+   * The array will be empty if there are no parents.
+   */
+  SpanId[] getParents();
+
+  /**
+   * Set the parents of this span.<p/>
+   *
+   * Any existing parents will be cleared by this call.
+   */
+  void setParents(SpanId[] parents);
+
+  /**
+   * Add a data annotation associated with this span
+   */
+  void addKVAnnotation(String key, String value);
+
+  /**
+   * Add a timeline annotation associated with this span
+   */
+  void addTimelineAnnotation(String msg);
+
+  /**
+   * Get data associated with this span (read only)<p/>
+   *
+   * Will never be null.
+   */
+  Map<String, String> getKVAnnotations();
+
+  /**
+   * Get any timeline annotations (read only)<p/>
+   *
+   * Will never be null.
+   */
+  List<TimelineAnnotation> getTimelineAnnotations();
+
+  /**
+   * Return a unique id for the process from which this Span originated.<p/>
+   *
+   * Will never be null.
+   */
+  String getTracerId();
+
+  /**
+   * Set the process id of a span.
+   */
+  void setTracerId(String s);
+
+  /**
+   * Serialize to Json
+   */
+  String toJson();
+
+  public static class SpanSerializer extends JsonSerializer<Span> {
+    @Override
+    public void serialize(Span span, JsonGenerator jgen, SerializerProvider provider)
+        throws IOException {
+      jgen.writeStartObject();
+      if (span.getSpanId().isValid()) {
+        jgen.writeStringField("a", span.getSpanId().toString());
+      }
+      if (span.getStartTimeMillis() != 0) {
+        jgen.writeNumberField("b", span.getStartTimeMillis());
+      }
+      if (span.getStopTimeMillis() != 0) {
+        jgen.writeNumberField("e", span.getStopTimeMillis());
+      }
+      if (!span.getDescription().isEmpty()) {
+        jgen.writeStringField("d", span.getDescription());
+      }
+      String tracerId = span.getTracerId();
+      if (!tracerId.isEmpty()) {
+        jgen.writeStringField("r", tracerId);
+      }
+      jgen.writeArrayFieldStart("p");
+      for (SpanId parent : span.getParents()) {
+        jgen.writeString(parent.toString());
+      }
+      jgen.writeEndArray();
+      Map<String, String> traceInfoMap = span.getKVAnnotations();
+      if (!traceInfoMap.isEmpty()) {
+        jgen.writeObjectFieldStart("n");
+        for (Map.Entry<String, String> e : traceInfoMap.entrySet()) {
+          jgen.writeStringField(e.getKey(), e.getValue());
+        }
+        jgen.writeEndObject();
+      }
+      List<TimelineAnnotation> timelineAnnotations =
+          span.getTimelineAnnotations();
+      if (!timelineAnnotations.isEmpty()) {
+        jgen.writeArrayFieldStart("t");
+        for (TimelineAnnotation tl : timelineAnnotations) {
+          jgen.writeStartObject();
+          jgen.writeNumberField("t", tl.getTime());
+          jgen.writeStringField("m", tl.getMessage());
+          jgen.writeEndObject();
+        }
+        jgen.writeEndArray();
+      }
+      jgen.writeEndObject();
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/SpanId.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/SpanId.java b/htrace-core/src/main/java/org/apache/htrace/core/SpanId.java
new file mode 100644
index 0000000..e10f894
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/SpanId.java
@@ -0,0 +1,149 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.math.BigInteger;
+import java.lang.Void;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.Random;
+
+/**
+ * Uniquely identifies an HTrace span.
+ *
+ * Span IDs are 128 bits in total.  The upper 64 bits of a span ID is the same
+ * as the upper 64 bits of the parent span, if there is one.  The lower 64 bits
+ * are always random.
+ */
+public final class SpanId implements Comparable<SpanId> {
+  private static final int SPAN_ID_STRING_LENGTH = 32;
+  private final long high;
+  private final long low;
+
+  /**
+   * The invalid span ID, which is all zeroes.
+   *
+   * It is also the "least" span ID in the sense that it is considered
+   * smaller than any other span ID.
+   */
+  public static SpanId INVALID = new SpanId(0, 0);
+
+  private static long nonZeroRand64() {
+    while (true) {
+      long r = ThreadLocalRandom.current().nextLong();
+      if (r != 0) {
+        return r;
+      }
+    }
+  }
+
+  public static SpanId fromRandom() {
+    return new SpanId(nonZeroRand64(), nonZeroRand64());
+  }
+
+  public static SpanId fromString(String str) {
+    if (str.length() != SPAN_ID_STRING_LENGTH) {
+      throw new RuntimeException("Invalid SpanID string: length was not " +
+          SPAN_ID_STRING_LENGTH);
+    }
+    long high =
+      ((Long.parseLong(str.substring(0, 8), 16)) << 32) |
+      (Long.parseLong(str.substring(8, 16), 16));
+    long low =
+      ((Long.parseLong(str.substring(16, 24), 16)) << 32) |
+      (Long.parseLong(str.substring(24, 32), 16));
+    return new SpanId(high, low);
+  }
+
+  public SpanId(long high, long low) {
+    this.high = high;
+    this.low = low;
+  }
+
+  public long getHigh() {
+    return high;
+  }
+
+  public long getLow() {
+    return low;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (!(o instanceof SpanId)) {
+      return false;
+    }
+    SpanId other = (SpanId)o;
+    return ((other.high == high) && (other.low == low));
+  }
+
+  @Override
+  public int compareTo(SpanId other) {
+    int cmp = compareAsUnsigned(high, other.high);
+    if (cmp != 0) {
+      return cmp;
+    }
+    return compareAsUnsigned(low, other.low);
+  }
+
+  private static int compareAsUnsigned(long a, long b) {
+    boolean aSign = a < 0;
+    boolean bSign = b < 0;
+    if (aSign != bSign) {
+      if (aSign) {
+        return 1;
+      } else {
+        return -1;
+      }
+    }
+    if (aSign) {
+      a = -a;
+      b = -b;
+    }
+    if (a < b) {
+      return -1;
+    } else if (a > b) {
+      return 1;
+    } else {
+      return 0;
+    }
+  }
+
+  @Override
+  public int hashCode() {
+    return (int)((0xffffffff & (high >> 32))) ^
+           (int)((0xffffffff & (high >> 0))) ^
+           (int)((0xffffffff & (low >> 32))) ^
+           (int)((0xffffffff & (low >> 0)));
+  }
+
+  @Override
+  public String toString() {
+    return String.format("%08x%08x%08x%08x",
+        (0x00000000ffffffffL & (high >> 32)),
+        (0x00000000ffffffffL & high),
+        (0x00000000ffffffffL & (low >> 32)),
+        (0x00000000ffffffffL & low));
+  }
+
+  public boolean isValid() {
+    return (high != 0)  || (low != 0);
+  }
+
+  public SpanId newChildId() {
+    return new SpanId(high, nonZeroRand64());
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/SpanReceiver.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/SpanReceiver.java b/htrace-core/src/main/java/org/apache/htrace/core/SpanReceiver.java
new file mode 100644
index 0000000..5547c51
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/SpanReceiver.java
@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+
+import java.io.Closeable;
+
+
+/**
+ * The collector within a process that is the destination of Spans when a trace is running.
+ * {@code SpanReceiver} implementations are expected to provide a constructor with the signature
+ * <p>
+ * <pre>
+ * <code>public SpanReceiverImpl(HTraceConfiguration)</code>
+ * </pre>
+ * The helper class {@link org.apache.htrace.SpanReceiverBuilder} provides convenient factory
+ * methods for creating {@code SpanReceiver} instances from configuration.
+ * @see org.apache.htrace.SpanReceiverBuilder
+ */
+public interface SpanReceiver extends Closeable {
+  /**
+   * Called when a Span is stopped and can now be stored.
+   */
+  public void receiveSpan(Span span);
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/SpanReceiverBuilder.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/SpanReceiverBuilder.java b/htrace-core/src/main/java/org/apache/htrace/core/SpanReceiverBuilder.java
new file mode 100644
index 0000000..3ab0b07
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/SpanReceiverBuilder.java
@@ -0,0 +1,138 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.lang.reflect.Constructor;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * A {@link SpanReceiver} builder. It reads a {@link SpanReceiver} class name from the provided
+ * configuration using the {@link #SPAN_RECEIVER_CONF_KEY} key. Unqualified class names
+ * are interpreted as members of the {@code org.apache.htrace.impl} package. The {@link #build()}
+ * method constructs an instance of that class, initialized with the same configuration.
+ */
+public class SpanReceiverBuilder {
+  private static final Log LOG = LogFactory.getLog(SpanReceiverBuilder.class);
+
+  public final static String SPAN_RECEIVER_CONF_KEY = "span.receiver";
+  private final static String DEFAULT_PACKAGE = "org.apache.htrace.core";
+  private final static ClassLoader classLoader =
+      SpanReceiverBuilder.class.getClassLoader();
+  private final HTraceConfiguration conf;
+  private boolean logErrors;
+  private String spanReceiverClass;
+
+  public SpanReceiverBuilder(HTraceConfiguration conf) {
+    this.conf = conf;
+    reset();
+  }
+
+  /**
+   * Set this builder back to defaults. Any previous calls to {@link #spanReceiverClass(String)}
+   * are overridden by the value provided by configuration.
+   * @return This instance
+   */
+  public SpanReceiverBuilder reset() {
+    this.logErrors = true;
+    this.spanReceiverClass = this.conf.get(SPAN_RECEIVER_CONF_KEY);
+    return this;
+  }
+
+  /**
+   * Override the {@code SpanReceiver} class name provided in configuration with a new value.
+   * @return This instance
+   */
+  public SpanReceiverBuilder spanReceiverClass(final String spanReceiverClass) {
+    this.spanReceiverClass = spanReceiverClass;
+    return this;
+  }
+
+  /**
+   * Configure whether we should log errors during build().
+   * @return This instance
+   */
+  public SpanReceiverBuilder logErrors(boolean logErrors) {
+    this.logErrors = logErrors;
+    return this;
+  }
+
+  private void logError(String errorStr) {
+    if (!logErrors) {
+      return;
+    }
+    LOG.error(errorStr);
+  }
+
+  private void logError(String errorStr, Throwable e) {
+    if (!logErrors) {
+      return;
+    }
+    LOG.error(errorStr, e);
+  }
+
+  public SpanReceiver build() {
+    SpanReceiver spanReceiver = newSpanReceiver();
+    if (LOG.isTraceEnabled()) {
+      LOG.trace("Created new span receiver of type " +
+             ((spanReceiver == null) ? "(none)" :
+               spanReceiver.getClass().getName()));
+    }
+    return spanReceiver;
+  }
+
+  private SpanReceiver newSpanReceiver() {
+    if ((this.spanReceiverClass == null) ||
+        this.spanReceiverClass.isEmpty()) {
+      LOG.debug("No span receiver class specified.");
+      return null;
+    }
+    String str = spanReceiverClass;
+    if (!str.contains(".")) {
+      str = DEFAULT_PACKAGE + "." + str;
+    }
+    Class cls = null;
+    try {
+      cls = classLoader.loadClass(str);
+    } catch (ClassNotFoundException e) {
+      logError("SpanReceiverBuilder cannot find SpanReceiver class " + str +
+          ": disabling span receiver.");
+      return null;
+    }
+    Constructor<SpanReceiver> ctor = null;
+    try {
+      ctor = cls.getConstructor(HTraceConfiguration.class);
+    } catch (NoSuchMethodException e) {
+      logError("SpanReceiverBuilder cannot find a constructor for class " +
+          str + "which takes an HTraceConfiguration.  Disabling span " +
+          "receiver.");
+      return null;
+    }
+    try {
+      LOG.debug("Creating new instance of " + str + "...");
+      return ctor.newInstance(conf);
+    } catch (ReflectiveOperationException e) {
+      logError("SpanReceiverBuilder reflection error when constructing " + str +
+          ".  Disabling span receiver.", e);
+      return null;
+    } catch (Throwable e) {
+      logError("SpanReceiverBuilder constructor error when constructing " + str +
+          ".  Disabling span receiver.", e);
+      return null;
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/StandardOutSpanReceiver.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/StandardOutSpanReceiver.java b/htrace-core/src/main/java/org/apache/htrace/core/StandardOutSpanReceiver.java
new file mode 100644
index 0000000..b084046
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/StandardOutSpanReceiver.java
@@ -0,0 +1,42 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import java.io.IOException;
+
+/**
+ * Used for testing. Simply prints to standard out any spans it receives.
+ */
+public class StandardOutSpanReceiver implements SpanReceiver {
+  private static final Log LOG = LogFactory.getLog(StandardOutSpanReceiver.class);
+
+  public StandardOutSpanReceiver(HTraceConfiguration conf) {
+    LOG.trace("Created new StandardOutSpanReceiver.");
+  }
+
+  @Override
+  public void receiveSpan(Span span) {
+    System.out.println(span);
+  }
+
+  @Override
+  public void close() throws IOException {
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/TimelineAnnotation.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/TimelineAnnotation.java b/htrace-core/src/main/java/org/apache/htrace/core/TimelineAnnotation.java
new file mode 100644
index 0000000..18de061
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/TimelineAnnotation.java
@@ -0,0 +1,40 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+public class TimelineAnnotation {
+  private final long time;
+  private final String msg;
+
+  public TimelineAnnotation(long time, String msg) {
+    this.time = time;
+    this.msg = msg;
+  }
+
+  public long getTime() {
+    return time;
+  }
+
+  public String getMessage() {
+    return msg;
+  }
+
+  @Override
+  public String toString() {
+    return "@" + time + ": " + msg;
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/Trace.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/Trace.java b/htrace-core/src/main/java/org/apache/htrace/core/Trace.java
new file mode 100644
index 0000000..9b72afe
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/Trace.java
@@ -0,0 +1,219 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import java.util.concurrent.Callable;
+
+/**
+ * The Trace class is the primary way to interact with the library.  It provides
+ * methods to create and manipulate spans.
+ *
+ * A 'Span' represents a length of time.  It has many other attributes such as a
+ * description, ID, and even potentially a set of key/value strings attached to
+ * it.
+ *
+ * Each thread in your application has a single currently active currentSpan
+ * associated with it.  When this is non-null, it represents the current
+ * operation that the thread is doing.  Spans are NOT thread-safe, and must
+ * never be used by multiple threads at once.  With care, it is possible to
+ * safely pass a Span object between threads, but in most cases this is not
+ * necessary.
+ *
+ * A 'TraceScope' can either be empty, or contain a Span.  TraceScope objects
+ * implement the Java's Closeable interface.  Similar to file descriptors, they
+ * must be closed after they are created.  When a TraceScope contains a Span,
+ * this span is closed when the scope is closed.
+ *
+ * The 'startSpan' methods in this class do a few things:
+ * <ul>
+ *   <li>Create a new Span which has this thread's currentSpan as one of its parents.</li>
+ *   <li>Set currentSpan to the new Span.</li>
+ *   <li>Create a TraceSpan object to manage the new Span.</li>
+ * </ul>
+ *
+ * Closing a TraceScope does a few things:
+ * <ul>
+ *   <li>It closes the span which the scope was managing.</li>
+ *   <li>Set currentSpan to the previous currentSpan (which may be null).</li>
+ * </ul>
+ */
+public class Trace {
+  private static final Log LOG = LogFactory.getLog(Trace.class);
+
+  /**
+   * Creates a new trace scope.
+   *
+   * If this thread has a currently active trace span, the trace scope we create
+   * here will contain a new span descending from the currently active span.
+   * If there is no currently active trace span, the trace scope we create will
+   * be empty.
+   *
+   * @param description   The description field for the new span to create.
+   */
+  public static TraceScope startSpan(String description) {
+    return startSpan(description, NeverSampler.INSTANCE);
+  }
+
+  public static TraceScope startSpan(String description, SpanId parentId) {
+    if (parentId == null) {
+      return continueSpan(null);
+    }
+    Span newSpan = new MilliSpan.Builder().
+        begin(System.currentTimeMillis()).
+        end(0).
+        description(description).
+        spanId(parentId.newChildId()).
+        parents(new SpanId[] { parentId }).
+        build();
+    return continueSpan(newSpan);
+  }
+
+  /**
+   * Creates a new trace scope.
+   *
+   * If this thread has a currently active trace span, it must be the 'parent'
+   * span that you pass in here as a parameter.  The trace scope we create here
+   * will contain a new span which is a child of 'parent'.
+   *
+   * @param description   The description field for the new span to create.
+   */
+  public static TraceScope startSpan(String description, Span parent) {
+    if (parent == null) {
+      return startSpan(description);
+    }
+    Span currentSpan = currentSpan();
+    if ((currentSpan != null) && (currentSpan != parent)) {
+      Tracer.clientError("HTrace client error: thread " +
+          Thread.currentThread().getName() + " tried to start a new Span " +
+          "with parent " + parent.toString() + ", but there is already a " +
+          "currentSpan " + currentSpan);
+    }
+    return continueSpan(parent.child(description));
+  }
+
+  public static <T> TraceScope startSpan(String description, Sampler s) {
+    Span span = null;
+    if (isTracing() || s.next()) {
+      span = Tracer.getInstance().createNew(description);
+    }
+    return continueSpan(span);
+  }
+
+  /**
+   * Pick up an existing span from another thread.
+   */
+  public static TraceScope continueSpan(Span s) {
+    // Return an empty TraceScope that does nothing on close
+    if (s == null) return NullScope.INSTANCE;
+    return Tracer.getInstance().continueSpan(s);
+  }
+
+  /**
+   * Removes the given SpanReceiver from the list of SpanReceivers.
+   */
+  public static void removeReceiver(SpanReceiver rcvr) {
+    Tracer.getInstance().removeReceiver(rcvr);
+  }
+
+  /**
+   * Adds the given SpanReceiver to the current Tracer instance's list of
+   * SpanReceivers.
+   */
+  public static void addReceiver(SpanReceiver rcvr) {
+    Tracer.getInstance().addReceiver(rcvr);
+  }
+
+  /**
+   * Adds a data annotation to the current span if tracing is currently on.
+   */
+  public static void addKVAnnotation(String key, String value) {
+    Span s = currentSpan();
+    if (s != null) {
+      s.addKVAnnotation(key, value);
+    }
+  }
+
+  /**
+   * Annotate the current span with the given message.
+   */
+  public static void addTimelineAnnotation(String msg) {
+    Span s = currentSpan();
+    if (s != null) {
+      s.addTimelineAnnotation(msg);
+    }
+  }
+
+  /**
+   * Returns true if the current thread is a part of a trace, false otherwise.
+   */
+  public static boolean isTracing() {
+    return Tracer.getInstance().isTracing();
+  }
+
+  /**
+   * If we are tracing, return the current span, else null
+   *
+   * @return Span representing the current trace, or null if not tracing.
+   */
+  public static Span currentSpan() {
+    return Tracer.getInstance().currentSpan();
+  }
+
+  /**
+   * Wrap the callable in a TraceCallable, if tracing.
+   *
+   * @return The callable provided, wrapped if tracing, 'callable' if not.
+   */
+  public static <V> Callable<V> wrap(Callable<V> callable) {
+    if (isTracing()) {
+      return new TraceCallable<V>(Trace.currentSpan(), callable);
+    } else {
+      return callable;
+    }
+  }
+
+  /**
+   * Wrap the runnable in a TraceRunnable, if tracing
+   *
+   * @return The runnable provided, wrapped if tracing, 'runnable' if not.
+   */
+  public static Runnable wrap(Runnable runnable) {
+    if (isTracing()) {
+      return new TraceRunnable(Trace.currentSpan(), runnable);
+    } else {
+      return runnable;
+    }
+  }
+
+  /**
+   * Wrap the runnable in a TraceRunnable, if tracing
+   *
+   * @param description name of the span to be created.
+   * @param runnable The runnable that will have tracing info associated with it if tracing.
+   * @return The runnable provided, wrapped if tracing, 'runnable' if not.
+   */
+  public static Runnable wrap(String description, Runnable runnable) {
+    if (isTracing()) {
+      return new TraceRunnable(Trace.currentSpan(), runnable, description);
+    } else {
+      return runnable;
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/TraceCallable.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/TraceCallable.java b/htrace-core/src/main/java/org/apache/htrace/core/TraceCallable.java
new file mode 100644
index 0000000..08bcace
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/TraceCallable.java
@@ -0,0 +1,65 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.util.concurrent.Callable;
+
+/**
+ * Wrap a Callable with a Span that survives a change in threads.
+ */
+public class TraceCallable<V> implements Callable<V> {
+  private final Callable<V> impl;
+  private final Span parent;
+  private final String description;
+
+  public TraceCallable(Callable<V> impl) {
+    this(Trace.currentSpan(), impl);
+  }
+
+  public TraceCallable(Span parent, Callable<V> impl) {
+    this(parent, impl, null);
+  }
+
+  public TraceCallable(Span parent, Callable<V> impl, String description) {
+    this.impl = impl;
+    this.parent = parent;
+    this.description = description;
+  }
+
+  @Override
+  public V call() throws Exception {
+    if (parent != null) {
+      TraceScope chunk = Trace.startSpan(getDescription(), parent);
+
+      try {
+        return impl.call();
+      } finally {
+        chunk.close();
+      }
+    } else {
+      return impl.call();
+    }
+  }
+
+  public Callable<V> getImpl() {
+    return impl;
+  }
+
+  private String getDescription() {
+    return this.description == null ? Thread.currentThread().getName() : description;
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/TraceExecutorService.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/TraceExecutorService.java b/htrace-core/src/main/java/org/apache/htrace/core/TraceExecutorService.java
new file mode 100644
index 0000000..8519d04
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/TraceExecutorService.java
@@ -0,0 +1,118 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+
+public class TraceExecutorService implements ExecutorService {
+
+  private final ExecutorService impl;
+
+  public TraceExecutorService(ExecutorService impl) {
+    this.impl = impl;
+  }
+
+  @Override
+  public void execute(Runnable command) {
+    impl.execute(new TraceRunnable(command));
+  }
+
+  @Override
+  public void shutdown() {
+    impl.shutdown();
+  }
+
+  @Override
+  public List<Runnable> shutdownNow() {
+    return impl.shutdownNow();
+  }
+
+  @Override
+  public boolean isShutdown() {
+    return impl.isShutdown();
+  }
+
+  @Override
+  public boolean isTerminated() {
+    return impl.isTerminated();
+  }
+
+  @Override
+  public boolean awaitTermination(long timeout, TimeUnit unit)
+      throws InterruptedException {
+    return impl.awaitTermination(timeout, unit);
+  }
+
+  @Override
+  public <T> Future<T> submit(Callable<T> task) {
+    return impl.submit(new TraceCallable<T>(task));
+  }
+
+  @Override
+  public <T> Future<T> submit(Runnable task, T result) {
+    return impl.submit(new TraceRunnable(task), result);
+  }
+
+  @Override
+  public Future<?> submit(Runnable task) {
+    return impl.submit(new TraceRunnable(task));
+  }
+
+  private <T> Collection<? extends Callable<T>> wrapCollection(
+      Collection<? extends Callable<T>> tasks) {
+    List<Callable<T>> result = new ArrayList<Callable<T>>();
+    for (Callable<T> task : tasks) {
+      result.add(new TraceCallable<T>(task));
+    }
+    return result;
+  }
+
+  @Override
+  public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)
+      throws InterruptedException {
+    return impl.invokeAll(wrapCollection(tasks));
+  }
+
+  @Override
+  public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks,
+                                       long timeout, TimeUnit unit) throws InterruptedException {
+    return impl.invokeAll(wrapCollection(tasks), timeout, unit);
+  }
+
+  @Override
+  public <T> T invokeAny(Collection<? extends Callable<T>> tasks)
+      throws InterruptedException, ExecutionException {
+    return impl.invokeAny(wrapCollection(tasks));
+  }
+
+  @Override
+  public <T> T invokeAny(Collection<? extends Callable<T>> tasks, long timeout,
+                         TimeUnit unit) throws InterruptedException, ExecutionException,
+      TimeoutException {
+    return impl.invokeAny(wrapCollection(tasks), timeout, unit);
+  }
+
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/TraceProxy.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/TraceProxy.java b/htrace-core/src/main/java/org/apache/htrace/core/TraceProxy.java
new file mode 100644
index 0000000..de9c980
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/TraceProxy.java
@@ -0,0 +1,58 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+
+public class TraceProxy {
+  /**
+   * Returns an object that will trace all calls to itself.
+   */
+  public static <T> T trace(T instance) {
+    return trace(instance, Sampler.ALWAYS);
+  }
+
+  /**
+   * Returns an object that will trace all calls to itself.
+   */
+  @SuppressWarnings("unchecked")
+  public static <T, V> T trace(final T instance, final Sampler sampler) {
+    InvocationHandler handler = new InvocationHandler() {
+      @Override
+      public Object invoke(Object obj, Method method, Object[] args)
+          throws Throwable {
+        if (!sampler.next()) {
+          return method.invoke(instance, args);
+        }
+
+        TraceScope scope = Trace.startSpan(method.getName(), Sampler.ALWAYS);
+        try {
+          return method.invoke(instance, args);
+        } catch (Throwable ex) {
+          ex.printStackTrace();
+          throw ex;
+        } finally {
+          scope.close();
+        }
+      }
+    };
+    return (T) Proxy.newProxyInstance(instance.getClass().getClassLoader(),
+        instance.getClass().getInterfaces(), handler);
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/TraceRunnable.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/TraceRunnable.java b/htrace-core/src/main/java/org/apache/htrace/core/TraceRunnable.java
new file mode 100644
index 0000000..6accea9
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/TraceRunnable.java
@@ -0,0 +1,64 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+/**
+ * Wrap a Runnable with a Span that survives a change in threads.
+ */
+public class TraceRunnable implements Runnable {
+
+  private final Span parent;
+  private final Runnable runnable;
+  private final String description;
+
+  public TraceRunnable(Runnable runnable) {
+    this(Trace.currentSpan(), runnable);
+  }
+
+  public TraceRunnable(Span parent, Runnable runnable) {
+    this(parent, runnable, null);
+  }
+
+  public TraceRunnable(Span parent, Runnable runnable, String description) {
+    this.parent = parent;
+    this.runnable = runnable;
+    this.description = description;
+  }
+
+  @Override
+  public void run() {
+    if (parent != null) {
+      TraceScope chunk = Trace.startSpan(getDescription(), parent);
+
+      try {
+        runnable.run();
+      } finally {
+        chunk.close();
+      }
+    } else {
+      runnable.run();
+    }
+  }
+
+  private String getDescription() {
+    return this.description == null ? Thread.currentThread().getName() : description;
+  }
+
+  public Runnable getRunnable() {
+    return runnable;
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/TraceScope.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/TraceScope.java b/htrace-core/src/main/java/org/apache/htrace/core/TraceScope.java
new file mode 100644
index 0000000..f41e720
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/TraceScope.java
@@ -0,0 +1,99 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.io.Closeable;
+import java.lang.Thread;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+public class TraceScope implements Closeable {
+  private static final Log LOG = LogFactory.getLog(TraceScope.class);
+
+  /**
+   * the span for this scope
+   */
+  private final Span span;
+
+  /**
+   * the span that was "current" before this scope was entered
+   */
+  private final Span savedSpan;
+
+  private boolean detached = false;
+
+  TraceScope(Span span, Span saved) {
+    this.span = span;
+    this.savedSpan = saved;
+  }
+
+  public Span getSpan() {
+    return span;
+  }
+
+  /**
+   * Remove this span as the current thread, but don't stop it yet or
+   * send it for collection. This is useful if the span object is then
+   * passed to another thread for use with Trace.continueTrace().
+   *
+   * @return the same Span object
+   */
+  public Span detach() {
+    if (detached) {
+      Tracer.clientError("Tried to detach trace span " + span + " but " +
+          "it has already been detached.");
+    }
+    detached = true;
+
+    Span cur = Tracer.getInstance().currentSpan();
+    if (cur != span) {
+      Tracer.clientError("Tried to detach trace span " + span + " but " +
+          "it is not the current span for the " +
+          Thread.currentThread().getName() + " thread.  You have " +
+          "probably forgotten to close or detach " + cur);
+    } else {
+      Tracer.getInstance().setCurrentSpan(savedSpan);
+    }
+    return span;
+  }
+
+  /**
+   * Return true when {@link #detach()} has been called. Helpful when debugging
+   * multiple threads working on a single span.
+   */
+  public boolean isDetached() {
+    return detached;
+  }
+
+  @Override
+  public void close() {
+    if (detached) {
+      return;
+    }
+    detached = true;
+    Span cur = Tracer.getInstance().currentSpan();
+    if (cur != span) {
+      Tracer.clientError("Tried to close trace span " + span + " but " +
+          "it is not the current span for the " +
+          Thread.currentThread().getName() + " thread.  You have " +
+          "probably forgotten to close or detach " + cur);
+    } else {
+      span.stop();
+      Tracer.getInstance().setCurrentSpan(savedSpan);
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/Tracer.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/Tracer.java b/htrace-core/src/main/java/org/apache/htrace/core/Tracer.java
new file mode 100644
index 0000000..b2ef6e6
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/Tracer.java
@@ -0,0 +1,129 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * A Tracer provides the implementation for collecting and distributing Spans
+ * within a process.
+ */
+public class Tracer {
+  private static final Log LOG = LogFactory.getLog(Tracer.class);
+
+  static long nonZeroRandom64() {
+    long id;
+    Random random = ThreadLocalRandom.current();
+    do {
+      id = random.nextLong();
+    } while (id == 0);
+    return id;
+  }
+
+  private final List<SpanReceiver> receivers = new CopyOnWriteArrayList<SpanReceiver>();
+  private static final ThreadLocal<Span> currentSpan = new ThreadLocal<Span>() {
+    @Override
+    protected Span initialValue() {
+      return null;
+    }
+  };
+  private static final SpanId EMPTY_PARENT_ARRAY[] = new SpanId[0];
+
+  /**
+   * Log a client error, and throw an exception.
+   *
+   * @param str     The message to use in the log and the exception.
+   */
+  static void clientError(String str) {
+    LOG.error(str);
+    throw new RuntimeException(str);
+  }
+
+  /**
+   * Internal class for defered singleton idiom.
+   * <p/>
+   * https://en.wikipedia.org/wiki/Initialization_on_demand_holder_idiom
+   */
+  private static class TracerHolder {
+    private static final Tracer INSTANCE = new Tracer();
+  }
+
+  public static Tracer getInstance() {
+    return TracerHolder.INSTANCE;
+  }
+
+  protected Span createNew(String description) {
+    Span parent = currentSpan.get();
+    if (parent == null) {
+      return new MilliSpan.Builder().
+          begin(System.currentTimeMillis()).
+          end(0).
+          description(description).
+          parents(EMPTY_PARENT_ARRAY).
+          spanId(SpanId.fromRandom()).
+          build();
+    } else {
+      return parent.child(description);
+    }
+  }
+
+  protected boolean isTracing() {
+    return currentSpan.get() != null;
+  }
+
+  protected Span currentSpan() {
+    return currentSpan.get();
+  }
+
+  public void deliver(Span span) {
+    for (SpanReceiver receiver : receivers) {
+      receiver.receiveSpan(span);
+    }
+  }
+
+  protected void addReceiver(SpanReceiver receiver) {
+    receivers.add(receiver);
+  }
+
+  protected void removeReceiver(SpanReceiver receiver) {
+    receivers.remove(receiver);
+  }
+
+  protected Span setCurrentSpan(Span span) {
+    if (LOG.isTraceEnabled()) {
+      LOG.trace("setting current span " + span);
+    }
+    currentSpan.set(span);
+    return span;
+  }
+
+  public TraceScope continueSpan(Span s) {
+    Span oldCurrent = currentSpan();
+    setCurrentSpan(s);
+    return new TraceScope(s, oldCurrent);
+  }
+
+  protected int numReceivers() {
+    return receivers.size();
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/TracerId.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/TracerId.java b/htrace-core/src/main/java/org/apache/htrace/core/TracerId.java
new file mode 100644
index 0000000..7cdbd34
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/TracerId.java
@@ -0,0 +1,290 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.lang.management.ManagementFactory;
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.util.Enumeration;
+import java.util.Locale;
+import java.util.TreeSet;
+
+/**
+ * The HTrace tracer ID.<p/>
+ *
+ * HTrace tracer IDs are created from format strings.
+ * Format strings contain variables which the TracerId class will
+ * replace with the correct values at runtime.<p/>
+ *
+ * <ul>
+ * <li>${ip}: will be replaced with an ip address.</li>
+ * <li>${pname}: will be replaced the process name obtained from java.</li>
+ * </ul><p/>
+ *
+ * For example, the string "${pname}/${ip}" will be replaced with something
+ * like: DataNode/192.168.0.1, assuming that the process' name is DataNode
+ * and its IP address is 192.168.0.1.<p/>
+ *
+ * Process ID strings can contain backslashes as escapes.
+ * For example, "\a" will map to "a".  "\${ip}" will map to the literal
+ * string "${ip}", not the IP address.  A backslash itself can be escaped by a
+ * preceding backslash.
+ */
+public final class TracerId {
+  private static final Log LOG = LogFactory.getLog(TracerId.class);
+
+  /**
+   * The configuration key to use for process id
+   */
+  public static final String TRACER_ID_KEY = "process.id";
+
+  /**
+   * The default process ID to use if no other ID is configured.
+   */
+  private static final String DEFAULT_TRACER_ID = "${pname}/${ip}";
+
+  private final String tracerId;
+
+  TracerId(String fmt) {
+    StringBuilder bld = new StringBuilder();
+    StringBuilder varBld = null;
+    boolean escaping = false;
+    int varSeen = 0;
+    for (int i = 0, len = fmt.length() ; i < len; i++) {
+      char c = fmt.charAt(i);
+      if (c == '\\') {
+        if (!escaping) {
+          escaping = true;
+          continue;
+        }
+      }
+      switch (varSeen) {
+        case 0:
+          if (c == '$') {
+            if (!escaping) {
+              varSeen = 1;
+              continue;
+            }
+          }
+          escaping = false;
+          varSeen = 0;
+          bld.append(c);
+          break;
+        case 1:
+          if (c == '{') {
+            if (!escaping) {
+              varSeen = 2;
+              varBld = new StringBuilder();
+              continue;
+            }
+          }
+          escaping = false;
+          varSeen = 0;
+          bld.append("$").append(c);
+          break;
+        default:
+          if (c == '}') {
+            if (!escaping) {
+              String var = varBld.toString();
+              bld.append(processShellVar(var));
+              varBld = null;
+              varSeen = 0;
+              continue;
+            }
+          }
+          escaping = false;
+          varBld.append(c);
+          varSeen++;
+          break;
+      }
+    }
+    if (varSeen > 0) {
+      LOG.warn("Unterminated process ID substitution variable at the end " +
+          "of format string " + fmt);
+    }
+    this.tracerId = bld.toString();
+    if (LOG.isTraceEnabled()) {
+      LOG.trace("ProcessID(fmt=" + fmt + "): computed process ID of \"" +
+          this.tracerId + "\"");
+    }
+  }
+
+  public TracerId(HTraceConfiguration conf) {
+    this(conf.get(TRACER_ID_KEY, DEFAULT_TRACER_ID));
+  }
+
+  private String processShellVar(String var) {
+    if (var.equals("pname")) {
+      return getProcessName();
+    } else if (var.equals("ip")) {
+      return getBestIpString();
+    } else if (var.equals("pid")) {
+      return Long.valueOf(getOsPid()).toString();
+    } else {
+      LOG.warn("unknown ProcessID variable " + var);
+      return "";
+    }
+  }
+
+  static String getProcessName() {
+    String cmdLine = System.getProperty("sun.java.command");
+    if (cmdLine != null && !cmdLine.isEmpty()) {
+      String fullClassName = cmdLine.split("\\s+")[0];
+      String[] classParts = fullClassName.split("\\.");
+      cmdLine = classParts[classParts.length - 1];
+    }
+    return (cmdLine == null || cmdLine.isEmpty()) ? "Unknown" : cmdLine;
+  }
+
+  /**
+   * Get the best IP address that represents this node.<p/>
+   *
+   * This is complicated since nodes can have multiple network interfaces,
+   * and each network interface can have multiple IP addresses.  What we're
+   * looking for here is an IP address that will serve to identify this node
+   * to HTrace.  So we prefer site-local addresess (i.e. private ones on the
+   * LAN) to publicly routable interfaces.  If there are multiple addresses
+   * to choose from, we select the one which comes first in textual sort
+   * order.  This should ensure that we at least consistently call each node
+   * by a single name.
+   */
+  static String getBestIpString() {
+    Enumeration<NetworkInterface> ifaces;
+    try {
+      ifaces = NetworkInterface.getNetworkInterfaces();
+    } catch (SocketException e) {
+      LOG.error("Error getting network interfaces", e);
+      return "127.0.0.1";
+    }
+    TreeSet<String> siteLocalCandidates = new TreeSet<String>();
+    TreeSet<String> candidates = new TreeSet<String>();
+    while (ifaces.hasMoreElements()) {
+      NetworkInterface iface = ifaces.nextElement();
+      for (Enumeration<InetAddress> addrs =
+               iface.getInetAddresses(); addrs.hasMoreElements();) {
+        InetAddress addr = addrs.nextElement();
+        if (!addr.isLoopbackAddress()) {
+          if (addr.isSiteLocalAddress()) {
+            siteLocalCandidates.add(addr.getHostAddress());
+          } else {
+            candidates.add(addr.getHostAddress());
+          }
+        }
+      }
+    }
+    if (!siteLocalCandidates.isEmpty()) {
+      return siteLocalCandidates.first();
+    }
+    if (!candidates.isEmpty()) {
+      return candidates.first();
+    }
+    return "127.0.0.1";
+  }
+
+  /**
+   * Get the process id from the operating system.<p/>
+   *
+   * Unfortunately, there is no simple method to get the process id in Java.
+   * The approach we take here is to use the shell method (see
+   * {TracerId#getOsPidFromShellPpid}) unless we are on Windows, where the
+   * shell is not available.  On Windows, we use
+   * {TracerId#getOsPidFromManagementFactory}, which depends on some
+   * undocumented features of the JVM, but which doesn't require a shell.
+   */
+  static long getOsPid() {
+    if ((System.getProperty("os.name", "generic").toLowerCase(Locale.ENGLISH)).
+        contains("windows")) {
+      return getOsPidFromManagementFactory();
+    } else {
+      return getOsPidFromShellPpid();
+    }
+  }
+
+  /**
+   * Get the process ID by executing a shell and printing the PPID (parent
+   * process ID).<p/>
+   *
+   * This method of getting the process ID doesn't depend on any undocumented
+   * features of the virtual machine, and should work on almost any UNIX
+   * operating system.
+   */
+  private static long getOsPidFromShellPpid() {
+    Process p = null;
+    StringBuilder sb = new StringBuilder();
+    try {
+      p = new ProcessBuilder("/usr/bin/env", "sh", "-c", "echo $PPID").
+        redirectErrorStream(true).start();
+      BufferedReader reader = new BufferedReader(
+          new InputStreamReader(p.getInputStream()));
+      String line = "";
+      while ((line = reader.readLine()) != null) {
+        sb.append(line.trim());
+      }
+      int exitVal = p.waitFor();
+      if (exitVal != 0) {
+        throw new IOException("Process exited with error code " +
+            Integer.valueOf(exitVal).toString());
+      }
+    } catch (InterruptedException e) {
+      LOG.error("Interrupted while getting operating system pid from " +
+          "the shell.", e);
+      return 0L;
+    } catch (IOException e) {
+      LOG.error("Error getting operating system pid from the shell.", e);
+      return 0L;
+    } finally {
+      if (p != null) {
+        p.destroy();
+      }
+    }
+    try {
+      return Long.parseLong(sb.toString());
+    } catch (NumberFormatException e) {
+      LOG.error("Error parsing operating system pid from the shell.", e);
+      return 0L;
+    }
+  }
+
+  /**
+   * Get the process ID by looking at the name of the managed bean for the
+   * runtime system of the Java virtual machine.<p/>
+   *
+   * Although this is undocumented, in the Oracle JVM this name is of the form
+   * [OS_PROCESS_ID]@[HOSTNAME].
+   */
+  private static long getOsPidFromManagementFactory() {
+    try {
+      return Long.parseLong(ManagementFactory.getRuntimeMXBean().
+          getName().split("@")[0]);
+    } catch (NumberFormatException e) {
+      LOG.error("Failed to get the operating system process ID from the name " +
+          "of the managed bean for the JVM.", e);
+      return 0L;
+    }
+  }
+
+  public String get() {
+    return tracerId;
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/impl/AlwaysSampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/impl/AlwaysSampler.java b/htrace-core/src/main/java/org/apache/htrace/impl/AlwaysSampler.java
deleted file mode 100644
index 699f970..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/impl/AlwaysSampler.java
+++ /dev/null
@@ -1,36 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import org.apache.htrace.HTraceConfiguration;
-import org.apache.htrace.Sampler;
-
-/**
- * A Sampler that always returns true.
- */
-public final class AlwaysSampler implements Sampler {
-
-  public static final AlwaysSampler INSTANCE = new AlwaysSampler(null);
-
-  public AlwaysSampler(HTraceConfiguration conf) {
-  }
-
-  @Override
-  public boolean next() {
-    return true;
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/impl/CountSampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/impl/CountSampler.java b/htrace-core/src/main/java/org/apache/htrace/impl/CountSampler.java
deleted file mode 100644
index e59a4ba..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/impl/CountSampler.java
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import org.apache.htrace.HTraceConfiguration;
-import org.apache.htrace.Sampler;
-
-import java.util.Random;
-import java.util.concurrent.ThreadLocalRandom;
-
-/**
- * Sampler that returns true every N calls. Specify the frequency interval by configuring a
- * {@code long} value for {@link #SAMPLER_FREQUENCY_CONF_KEY}.
- */
-public class CountSampler implements Sampler {
-  public final static String SAMPLER_FREQUENCY_CONF_KEY = "sampler.frequency";
-
-  final long frequency;
-  long count = ThreadLocalRandom.current().nextLong();
-
-  public CountSampler(HTraceConfiguration conf) {
-    this.frequency = Long.parseLong(conf.get(SAMPLER_FREQUENCY_CONF_KEY), 10);
-  }
-
-  @Override
-  public boolean next() {
-    return (count++ % frequency) == 0;
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/impl/LocalFileSpanReceiver.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/impl/LocalFileSpanReceiver.java b/htrace-core/src/main/java/org/apache/htrace/impl/LocalFileSpanReceiver.java
deleted file mode 100644
index dfb701d..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/impl/LocalFileSpanReceiver.java
+++ /dev/null
@@ -1,264 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.ObjectWriter;
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.htrace.HTraceConfiguration;
-import org.apache.htrace.Span;
-import org.apache.htrace.SpanReceiver;
-
-import java.io.BufferedReader;
-import java.io.BufferedWriter;
-import java.io.EOFException;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.FileWriter;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.nio.ByteBuffer;
-import java.nio.channels.FileChannel;
-import java.nio.file.FileSystems;
-import java.nio.file.StandardOpenOption;
-import java.util.UUID;
-import java.util.concurrent.locks.ReentrantLock;
-
-/**
- * Writes the spans it receives to a local file.
- */
-public class LocalFileSpanReceiver implements SpanReceiver {
-  private static final Log LOG = LogFactory.getLog(LocalFileSpanReceiver.class);
-  public static final String PATH_KEY = "local-file-span-receiver.path";
-  public static final String CAPACITY_KEY = "local-file-span-receiver.capacity";
-  public static final int CAPACITY_DEFAULT = 5000;
-  private static ObjectWriter JSON_WRITER = new ObjectMapper().writer();
-  private final String path;
-
-  private byte[][] bufferedSpans;
-  private int bufferedSpansIndex;
-  private final ReentrantLock bufferLock = new ReentrantLock();
-
-  private final FileOutputStream stream;
-  private final FileChannel channel;
-  private final ReentrantLock channelLock = new ReentrantLock();
-  private final TracerId tracerId;
-
-  public LocalFileSpanReceiver(HTraceConfiguration conf) {
-    int capacity = conf.getInt(CAPACITY_KEY, CAPACITY_DEFAULT);
-    if (capacity < 1) {
-      throw new IllegalArgumentException(CAPACITY_KEY + " must not be " +
-          "less than 1.");
-    }
-    this.path = conf.get(PATH_KEY);
-    if (path == null || path.isEmpty()) {
-      throw new IllegalArgumentException("must configure " + PATH_KEY);
-    }
-    boolean success = false;
-    try {
-      this.stream = new FileOutputStream(path, true);
-    } catch (IOException ioe) {
-      LOG.error("Error opening " + path + ": " + ioe.getMessage());
-      throw new RuntimeException(ioe);
-    }
-    this.channel = stream.getChannel();
-    if (this.channel == null) {
-      try {
-        this.stream.close();
-      } catch (IOException e) {
-        LOG.error("Error closing " + path, e);
-      }
-      LOG.error("Failed to get channel for " + path);
-      throw new RuntimeException("Failed to get channel for " + path);
-    }
-    this.bufferedSpans = new byte[capacity][];
-    this.bufferedSpansIndex = 0;
-    if (LOG.isDebugEnabled()) {
-      LOG.debug("Created new LocalFileSpanReceiver with path = " + path +
-                ", capacity = " + capacity);
-    }
-    this.tracerId = new TracerId(conf);
-  }
-
-  /**
-   * Number of buffers to use in FileChannel#write.
-   *
-   * On UNIX, FileChannel#write uses writev-- a kernel interface that allows
-   * us to send multiple buffers at once.  This is more efficient than making a
-   * separate write call for each buffer, since it minimizes the number of
-   * transitions from userspace to kernel space.
-   */
-  private final int WRITEV_SIZE = 20;
-
-  private final static ByteBuffer newlineBuf = 
-      ByteBuffer.wrap(new byte[] { (byte)0xa });
-
-  /**
-   * Flushes a bufferedSpans array.
-   */
-  private void doFlush(byte[][] toFlush, int len) throws IOException {
-    int bidx = 0, widx = 0;
-    ByteBuffer writevBufs[] = new ByteBuffer[2 * WRITEV_SIZE];
-
-    while (true) {
-      if (widx == writevBufs.length) {
-        channel.write(writevBufs);
-        widx = 0;
-      }
-      if (bidx == len) {
-        break;
-      }
-      writevBufs[widx] = ByteBuffer.wrap(toFlush[bidx]);
-      writevBufs[widx + 1] = newlineBuf;
-      bidx++;
-      widx+=2;
-    }
-    if (widx > 0) {
-      channel.write(writevBufs, 0, widx);
-    }
-  }
-
-  @Override
-  public void receiveSpan(Span span) {
-    if (span.getTracerId().isEmpty()) {
-      span.setTracerId(tracerId.get());
-    }
-
-    // Serialize the span data into a byte[].  Note that we're not holding the
-    // lock here, to improve concurrency.
-    byte jsonBuf[] = null;
-    try {
-      jsonBuf = JSON_WRITER.writeValueAsBytes(span);
-    } catch (JsonProcessingException e) {
-        LOG.error("receiveSpan(path=" + path + ", span=" + span + "): " +
-                  "Json processing error: " + e.getMessage());
-      return;
-    }
-
-    // Grab the bufferLock and put our jsonBuf into the list of buffers to
-    // flush. 
-    byte toFlush[][] = null;
-    bufferLock.lock();
-    try {
-      if (bufferedSpans == null) {
-        LOG.debug("receiveSpan(path=" + path + ", span=" + span + "): " +
-                  "LocalFileSpanReceiver for " + path + " is closed.");
-        return;
-      }
-      bufferedSpans[bufferedSpansIndex] = jsonBuf;
-      bufferedSpansIndex++;
-      if (bufferedSpansIndex == bufferedSpans.length) {
-        // If we've hit the limit for the number of buffers to flush, 
-        // swap out the existing bufferedSpans array for a new array, and
-        // prepare to flush those spans to disk.
-        toFlush = bufferedSpans;
-        bufferedSpansIndex = 0;
-        bufferedSpans = new byte[bufferedSpans.length][];
-      }
-    } finally {
-      bufferLock.unlock();
-    }
-    if (toFlush != null) {
-      // We released the bufferLock above, to avoid blocking concurrent
-      // receiveSpan calls.  But now, we must take the channelLock, to make
-      // sure that we have sole access to the output channel.  If we did not do
-      // this, we might get interleaved output.
-      //
-      // There is a small chance that another thread doing a flush of more
-      // recent spans could get ahead of us here, and take the lock before we
-      // do.  This is ok, since spans don't have to be written out in order.
-      channelLock.lock();
-      try {
-        doFlush(toFlush, toFlush.length);
-      } catch (IOException ioe) {
-        LOG.error("Error flushing buffers to " + path + ": " +
-            ioe.getMessage());
-      } finally {
-        channelLock.unlock();
-      }
-    }
-  }
-
-  @Override
-  public void close() throws IOException {
-    byte toFlush[][] = null;
-    int numToFlush = 0;
-    bufferLock.lock();
-    try {
-      if (bufferedSpans == null) {
-        LOG.info("LocalFileSpanReceiver for " + path + " was already closed.");
-        return;
-      }
-      numToFlush = bufferedSpansIndex;
-      bufferedSpansIndex = 0;
-      toFlush = bufferedSpans;
-      bufferedSpans = null;
-    } finally {
-      bufferLock.unlock();
-    }
-    channelLock.lock();
-    try {
-      doFlush(toFlush, numToFlush);
-    } catch (IOException ioe) {
-      LOG.error("Error flushing buffers to " + path + ": " +
-          ioe.getMessage());
-    } finally {
-      try {
-        stream.close();
-      } catch (IOException e) {
-        LOG.error("Error closing stream for " + path, e);
-      }
-      channelLock.unlock();
-    }
-  }
-
-  public static String getUniqueLocalTraceFileName() {
-    String tmp = System.getProperty("java.io.tmpdir", "/tmp");
-    String nonce = null;
-    BufferedReader reader = null;
-    try {
-      // On Linux we can get a unique local file name by reading the process id
-      // out of /proc/self/stat.  (There isn't any portable way to get the
-      // process ID from Java.)
-      reader = new BufferedReader(
-          new InputStreamReader(new FileInputStream("/proc/self/stat"),
-                                "UTF-8"));
-      String line = reader.readLine();
-      if (line == null) {
-        throw new EOFException();
-      }
-      nonce = line.split(" ")[0];
-    } catch (IOException e) {
-    } finally {
-      if (reader != null) {
-        try {
-          reader.close();
-        } catch(IOException e) {
-          LOG.warn("Exception in closing " + reader, e);
-        }
-      }
-    }
-    if (nonce == null) {
-      // If we can't use the process ID, use a random nonce.
-      nonce = UUID.randomUUID().toString();
-    }
-    return new File(tmp, nonce).getAbsolutePath();
-  }
-}


[2/4] incubator-htrace git commit: HTRACE-211. Move htrace-core classes to the org.apache.htrace.core namespace (cmccabe)

Posted by cm...@apache.org.
http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/impl/MilliSpan.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/impl/MilliSpan.java b/htrace-core/src/main/java/org/apache/htrace/impl/MilliSpan.java
deleted file mode 100644
index 9d49cf9..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/impl/MilliSpan.java
+++ /dev/null
@@ -1,352 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import com.fasterxml.jackson.core.JsonParser;
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.DeserializationContext;
-import com.fasterxml.jackson.databind.JsonDeserializer;
-import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.ObjectReader;
-import com.fasterxml.jackson.databind.ObjectWriter;
-import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
-import org.apache.htrace.Span;
-import org.apache.htrace.SpanId;
-import org.apache.htrace.TimelineAnnotation;
-import org.apache.htrace.Tracer;
-
-import java.io.IOException;
-import java.io.StringWriter;
-import java.io.UnsupportedEncodingException;
-import java.math.BigInteger;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
-
-/**
- * A Span implementation that stores its information in milliseconds since the
- * epoch.
- */
-@JsonDeserialize(using = MilliSpan.MilliSpanDeserializer.class)
-public class MilliSpan implements Span {
-  private static ObjectMapper OBJECT_MAPPER = new ObjectMapper();
-  private static ObjectReader JSON_READER = OBJECT_MAPPER.reader(MilliSpan.class);
-  private static ObjectWriter JSON_WRITER = OBJECT_MAPPER.writer();
-  private static final SpanId EMPTY_PARENT_ARRAY[] = new SpanId[0];
-  private static final String EMPTY_STRING = "";
-
-  private long begin;
-  private long end;
-  private final String description;
-  private SpanId parents[];
-  private final SpanId spanId;
-  private Map<String, String> traceInfo = null;
-  private String tracerId;
-  private List<TimelineAnnotation> timeline = null;
-
-  @Override
-  public Span child(String childDescription) {
-    return new MilliSpan.Builder().
-      begin(System.currentTimeMillis()).
-      end(0).
-      description(childDescription).
-      parents(new SpanId[] {spanId}).
-      spanId(spanId.newChildId()).
-      tracerId(tracerId).
-      build();
-  }
-
-  /**
-   * The public interface for constructing a MilliSpan.
-   */
-  public static class Builder {
-    private long begin;
-    private long end;
-    private String description = EMPTY_STRING;
-    private SpanId parents[] = EMPTY_PARENT_ARRAY;
-    private SpanId spanId = SpanId.INVALID;
-    private Map<String, String> traceInfo = null;
-    private String tracerId = EMPTY_STRING;
-    private List<TimelineAnnotation> timeline = null;
-
-    public Builder() {
-    }
-
-    public Builder begin(long begin) {
-      this.begin = begin;
-      return this;
-    }
-
-    public Builder end(long end) {
-      this.end = end;
-      return this;
-    }
-
-    public Builder description(String description) {
-      this.description = description;
-      return this;
-    }
-
-    public Builder parents(SpanId parents[]) {
-      this.parents = parents;
-      return this;
-    }
-
-    public Builder parents(List<SpanId> parentList) {
-      SpanId[] parents = new SpanId[parentList.size()];
-      for (int i = 0; i < parentList.size(); i++) {
-        parents[i] = parentList.get(i);
-      }
-      this.parents = parents;
-      return this;
-    }
-
-    public Builder spanId(SpanId spanId) {
-      this.spanId = spanId;
-      return this;
-    }
-
-    public Builder traceInfo(Map<String, String> traceInfo) {
-      this.traceInfo = traceInfo.isEmpty() ? null : traceInfo;
-      return this;
-    }
-
-    public Builder tracerId(String tracerId) {
-      this.tracerId = tracerId;
-      return this;
-    }
-
-    public Builder timeline(List<TimelineAnnotation> timeline) {
-      this.timeline = timeline.isEmpty() ? null : timeline;
-      return this;
-    }
-
-    public MilliSpan build() {
-      return new MilliSpan(this);
-    }
-  }
-
-  public MilliSpan() {
-    this.begin = 0;
-    this.end = 0;
-    this.description = EMPTY_STRING;
-    this.parents = EMPTY_PARENT_ARRAY;
-    this.spanId = SpanId.INVALID;
-    this.traceInfo = null;
-    this.tracerId = EMPTY_STRING;
-    this.timeline = null;
-  }
-
-  private MilliSpan(Builder builder) {
-    this.begin = builder.begin;
-    this.end = builder.end;
-    this.description = builder.description;
-    this.parents = builder.parents;
-    this.spanId = builder.spanId;
-    this.traceInfo = builder.traceInfo;
-    this.tracerId = builder.tracerId;
-    this.timeline = builder.timeline;
-  }
-
-  @Override
-  public synchronized void stop() {
-    if (end == 0) {
-      if (begin == 0)
-        throw new IllegalStateException("Span for " + description
-            + " has not been started");
-      end = System.currentTimeMillis();
-      Tracer.getInstance().deliver(this);
-    }
-  }
-
-  protected long currentTimeMillis() {
-    return System.currentTimeMillis();
-  }
-
-  @Override
-  public synchronized boolean isRunning() {
-    return begin != 0 && end == 0;
-  }
-
-  @Override
-  public synchronized long getAccumulatedMillis() {
-    if (begin == 0)
-      return 0;
-    if (end > 0)
-      return end - begin;
-    return currentTimeMillis() - begin;
-  }
-
-  @Override
-  public String toString() {
-    return toJson();
-  }
-
-  @Override
-  public String getDescription() {
-    return description;
-  }
-
-  @Override
-  public SpanId getSpanId() {
-    return spanId;
-  }
-
-  @Override
-  public SpanId[] getParents() {
-    return parents;
-  }
-
-  @Override
-  public void setParents(SpanId[] parents) {
-    this.parents = parents;
-  }
-
-  @Override
-  public long getStartTimeMillis() {
-    return begin;
-  }
-
-  @Override
-  public long getStopTimeMillis() {
-    return end;
-  }
-
-  @Override
-  public void addKVAnnotation(String key, String value) {
-    if (traceInfo == null)
-      traceInfo = new HashMap<String, String>();
-    traceInfo.put(key, value);
-  }
-
-  @Override
-  public void addTimelineAnnotation(String msg) {
-    if (timeline == null) {
-      timeline = new ArrayList<TimelineAnnotation>();
-    }
-    timeline.add(new TimelineAnnotation(System.currentTimeMillis(), msg));
-  }
-
-  @Override
-  public Map<String, String> getKVAnnotations() {
-    if (traceInfo == null)
-      return Collections.emptyMap();
-    return Collections.unmodifiableMap(traceInfo);
-  }
-
-  @Override
-  public List<TimelineAnnotation> getTimelineAnnotations() {
-    if (timeline == null) {
-      return Collections.emptyList();
-    }
-    return Collections.unmodifiableList(timeline);
-  }
-
-  @Override
-  public String getTracerId() {
-    return tracerId;
-  }
-
-  @Override
-  public void setTracerId(String tracerId) {
-    this.tracerId = tracerId;
-  }
-
-  @Override
-  public String toJson() {
-    StringWriter writer = new StringWriter();
-    try {
-      JSON_WRITER.writeValue(writer, this);
-    } catch (IOException e) {
-      // An IOException should not be possible when writing to a string.
-      throw new RuntimeException(e);
-    }
-    return writer.toString();
-  }
-
-  public static class MilliSpanDeserializer
-        extends JsonDeserializer<MilliSpan> {
-    @Override
-    public MilliSpan deserialize(JsonParser jp, DeserializationContext ctxt)
-          throws IOException, JsonProcessingException {
-      JsonNode root = jp.getCodec().readTree(jp);
-      Builder builder = new Builder();
-      JsonNode bNode = root.get("b");
-      if (bNode != null) {
-        builder.begin(bNode.asLong());
-      }
-      JsonNode eNode = root.get("e");
-      if (eNode != null) {
-        builder.end(eNode.asLong());
-      }
-      JsonNode dNode = root.get("d");
-      if (dNode != null) {
-        builder.description(dNode.asText());
-      }
-      JsonNode sNode = root.get("a");
-      if (sNode != null) {
-        builder.spanId(SpanId.fromString(sNode.asText()));
-      }
-      JsonNode rNode = root.get("r");
-      if (rNode != null) {
-        builder.tracerId(rNode.asText());
-      }
-      JsonNode parentsNode = root.get("p");
-      LinkedList<SpanId> parents = new LinkedList<SpanId>();
-      if (parentsNode != null) {
-        for (Iterator<JsonNode> iter = parentsNode.elements();
-             iter.hasNext(); ) {
-          JsonNode parentIdNode = iter.next();
-          parents.add(SpanId.fromString(parentIdNode.asText()));
-        }
-      }
-      builder.parents(parents);
-      JsonNode traceInfoNode = root.get("n");
-      if (traceInfoNode != null) {
-        HashMap<String, String> traceInfo = new HashMap<String, String>();
-        for (Iterator<String> iter = traceInfoNode.fieldNames();
-             iter.hasNext(); ) {
-          String field = iter.next();
-          traceInfo.put(field, traceInfoNode.get(field).asText());
-        }
-        builder.traceInfo(traceInfo);
-      }
-      JsonNode timelineNode = root.get("t");
-      if (timelineNode != null) {
-        LinkedList<TimelineAnnotation> timeline =
-            new LinkedList<TimelineAnnotation>();
-        for (Iterator<JsonNode> iter = timelineNode.elements();
-             iter.hasNext(); ) {
-          JsonNode ann = iter.next();
-          timeline.add(new TimelineAnnotation(ann.get("t").asLong(),
-              ann.get("m").asText()));
-        }
-        builder.timeline(timeline);
-      }
-      return builder.build();
-    }
-  }
-
-  static MilliSpan fromJson(String json) throws IOException {
-    return JSON_READER.readValue(json);
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/impl/NeverSampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/impl/NeverSampler.java b/htrace-core/src/main/java/org/apache/htrace/impl/NeverSampler.java
deleted file mode 100644
index 3cb3827..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/impl/NeverSampler.java
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import org.apache.htrace.HTraceConfiguration;
-import org.apache.htrace.Sampler;
-
-/**
- * A Sampler that never returns true.
- */
-public final class NeverSampler implements Sampler {
-
-  public static final NeverSampler INSTANCE = new NeverSampler(null);
-
-  public NeverSampler(HTraceConfiguration conf) {
-  }
-
-  @Override
-  public boolean next() {
-    return false;
-  }
-
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/impl/POJOSpanReceiver.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/impl/POJOSpanReceiver.java b/htrace-core/src/main/java/org/apache/htrace/impl/POJOSpanReceiver.java
deleted file mode 100644
index 57e5299..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/impl/POJOSpanReceiver.java
+++ /dev/null
@@ -1,53 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import org.apache.htrace.HTraceConfiguration;
-import org.apache.htrace.Span;
-import org.apache.htrace.SpanReceiver;
-
-import java.io.IOException;
-import java.util.Collection;
-import java.util.HashSet;
-
-/**
- * SpanReceiver for testing only that just collects the Span objects it
- * receives. The spans it receives can be accessed with getSpans();
- */
-public class POJOSpanReceiver implements SpanReceiver {
-  private final Collection<Span> spans;
-
-  public POJOSpanReceiver(HTraceConfiguration conf) {
-    this.spans = new HashSet<Span>();
-  }
-
-  /**
-   * @return The spans this POJOSpanReceiver has received.
-   */
-  public Collection<Span> getSpans() {
-    return spans;
-  }
-
-  @Override
-  public void close() throws IOException {
-  }
-
-  @Override
-  public void receiveSpan(Span span) {
-    spans.add(span);
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/impl/ProbabilitySampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/impl/ProbabilitySampler.java b/htrace-core/src/main/java/org/apache/htrace/impl/ProbabilitySampler.java
deleted file mode 100644
index 903e590..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/impl/ProbabilitySampler.java
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.htrace.HTraceConfiguration;
-import org.apache.htrace.Sampler;
-
-import java.util.Random;
-import java.util.concurrent.ThreadLocalRandom;
-
-/**
- * Sampler that returns true a certain percentage of the time. Specify the frequency interval by
- * configuring a {@code double} value for {@link #SAMPLER_FRACTION_CONF_KEY}.
- */
-public class ProbabilitySampler implements Sampler {
-  private static final Log LOG = LogFactory.getLog(ProbabilitySampler.class);
-  public final double threshold;
-  public final static String SAMPLER_FRACTION_CONF_KEY = "sampler.fraction";
-
-  public ProbabilitySampler(HTraceConfiguration conf) {
-    this.threshold = Double.parseDouble(conf.get(SAMPLER_FRACTION_CONF_KEY));
-    if (LOG.isTraceEnabled()) {
-      LOG.trace("Created new ProbabilitySampler with threshold = " +
-                threshold + ".");
-    }
-  }
-
-  @Override
-  public boolean next() {
-    return ThreadLocalRandom.current().nextDouble() < threshold;
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/impl/StandardOutSpanReceiver.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/impl/StandardOutSpanReceiver.java b/htrace-core/src/main/java/org/apache/htrace/impl/StandardOutSpanReceiver.java
deleted file mode 100644
index f88af7f..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/impl/StandardOutSpanReceiver.java
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.htrace.HTraceConfiguration;
-import org.apache.htrace.Span;
-import org.apache.htrace.SpanReceiver;
-
-import java.io.IOException;
-
-/**
- * Used for testing. Simply prints to standard out any spans it receives.
- */
-public class StandardOutSpanReceiver implements SpanReceiver {
-  private static final Log LOG = LogFactory.getLog(StandardOutSpanReceiver.class);
-
-  public StandardOutSpanReceiver(HTraceConfiguration conf) {
-    LOG.trace("Created new StandardOutSpanReceiver.");
-  }
-
-  @Override
-  public void receiveSpan(Span span) {
-    System.out.println(span);
-  }
-
-  @Override
-  public void close() throws IOException {
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/impl/TracerId.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/impl/TracerId.java b/htrace-core/src/main/java/org/apache/htrace/impl/TracerId.java
deleted file mode 100644
index 83fa558..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/impl/TracerId.java
+++ /dev/null
@@ -1,291 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.impl;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.htrace.HTraceConfiguration;
-
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.lang.management.ManagementFactory;
-import java.net.InetAddress;
-import java.net.NetworkInterface;
-import java.net.SocketException;
-import java.util.Enumeration;
-import java.util.Locale;
-import java.util.TreeSet;
-
-/**
- * The HTrace tracer ID.<p/>
- *
- * HTrace tracer IDs are created from format strings.
- * Format strings contain variables which the TracerId class will
- * replace with the correct values at runtime.<p/>
- *
- * <ul>
- * <li>${ip}: will be replaced with an ip address.</li>
- * <li>${pname}: will be replaced the process name obtained from java.</li>
- * </ul><p/>
- *
- * For example, the string "${pname}/${ip}" will be replaced with something
- * like: DataNode/192.168.0.1, assuming that the process' name is DataNode
- * and its IP address is 192.168.0.1.<p/>
- *
- * Process ID strings can contain backslashes as escapes.
- * For example, "\a" will map to "a".  "\${ip}" will map to the literal
- * string "${ip}", not the IP address.  A backslash itself can be escaped by a
- * preceding backslash.
- */
-public final class TracerId {
-  private static final Log LOG = LogFactory.getLog(TracerId.class);
-
-  /**
-   * The configuration key to use for process id
-   */
-  public static final String TRACER_ID_KEY = "process.id";
-
-  /**
-   * The default process ID to use if no other ID is configured.
-   */
-  private static final String DEFAULT_TRACER_ID = "${pname}/${ip}";
-
-  private final String tracerId;
-
-  TracerId(String fmt) {
-    StringBuilder bld = new StringBuilder();
-    StringBuilder varBld = null;
-    boolean escaping = false;
-    int varSeen = 0;
-    for (int i = 0, len = fmt.length() ; i < len; i++) {
-      char c = fmt.charAt(i);
-      if (c == '\\') {
-        if (!escaping) {
-          escaping = true;
-          continue;
-        }
-      }
-      switch (varSeen) {
-        case 0:
-          if (c == '$') {
-            if (!escaping) {
-              varSeen = 1;
-              continue;
-            }
-          }
-          escaping = false;
-          varSeen = 0;
-          bld.append(c);
-          break;
-        case 1:
-          if (c == '{') {
-            if (!escaping) {
-              varSeen = 2;
-              varBld = new StringBuilder();
-              continue;
-            }
-          }
-          escaping = false;
-          varSeen = 0;
-          bld.append("$").append(c);
-          break;
-        default:
-          if (c == '}') {
-            if (!escaping) {
-              String var = varBld.toString();
-              bld.append(processShellVar(var));
-              varBld = null;
-              varSeen = 0;
-              continue;
-            }
-          }
-          escaping = false;
-          varBld.append(c);
-          varSeen++;
-          break;
-      }
-    }
-    if (varSeen > 0) {
-      LOG.warn("Unterminated process ID substitution variable at the end " +
-          "of format string " + fmt);
-    }
-    this.tracerId = bld.toString();
-    if (LOG.isTraceEnabled()) {
-      LOG.trace("ProcessID(fmt=" + fmt + "): computed process ID of \"" +
-          this.tracerId + "\"");
-    }
-  }
-
-  public TracerId(HTraceConfiguration conf) {
-    this(conf.get(TRACER_ID_KEY, DEFAULT_TRACER_ID));
-  }
-
-  private String processShellVar(String var) {
-    if (var.equals("pname")) {
-      return getProcessName();
-    } else if (var.equals("ip")) {
-      return getBestIpString();
-    } else if (var.equals("pid")) {
-      return Long.valueOf(getOsPid()).toString();
-    } else {
-      LOG.warn("unknown ProcessID variable " + var);
-      return "";
-    }
-  }
-
-  static String getProcessName() {
-    String cmdLine = System.getProperty("sun.java.command");
-    if (cmdLine != null && !cmdLine.isEmpty()) {
-      String fullClassName = cmdLine.split("\\s+")[0];
-      String[] classParts = fullClassName.split("\\.");
-      cmdLine = classParts[classParts.length - 1];
-    }
-    return (cmdLine == null || cmdLine.isEmpty()) ? "Unknown" : cmdLine;
-  }
-
-  /**
-   * Get the best IP address that represents this node.<p/>
-   *
-   * This is complicated since nodes can have multiple network interfaces,
-   * and each network interface can have multiple IP addresses.  What we're
-   * looking for here is an IP address that will serve to identify this node
-   * to HTrace.  So we prefer site-local addresess (i.e. private ones on the
-   * LAN) to publicly routable interfaces.  If there are multiple addresses
-   * to choose from, we select the one which comes first in textual sort
-   * order.  This should ensure that we at least consistently call each node
-   * by a single name.
-   */
-  static String getBestIpString() {
-    Enumeration<NetworkInterface> ifaces;
-    try {
-      ifaces = NetworkInterface.getNetworkInterfaces();
-    } catch (SocketException e) {
-      LOG.error("Error getting network interfaces", e);
-      return "127.0.0.1";
-    }
-    TreeSet<String> siteLocalCandidates = new TreeSet<String>();
-    TreeSet<String> candidates = new TreeSet<String>();
-    while (ifaces.hasMoreElements()) {
-      NetworkInterface iface = ifaces.nextElement();
-      for (Enumeration<InetAddress> addrs =
-               iface.getInetAddresses(); addrs.hasMoreElements();) {
-        InetAddress addr = addrs.nextElement();
-        if (!addr.isLoopbackAddress()) {
-          if (addr.isSiteLocalAddress()) {
-            siteLocalCandidates.add(addr.getHostAddress());
-          } else {
-            candidates.add(addr.getHostAddress());
-          }
-        }
-      }
-    }
-    if (!siteLocalCandidates.isEmpty()) {
-      return siteLocalCandidates.first();
-    }
-    if (!candidates.isEmpty()) {
-      return candidates.first();
-    }
-    return "127.0.0.1";
-  }
-
-  /**
-   * Get the process id from the operating system.<p/>
-   *
-   * Unfortunately, there is no simple method to get the process id in Java.
-   * The approach we take here is to use the shell method (see
-   * {TracerId#getOsPidFromShellPpid}) unless we are on Windows, where the
-   * shell is not available.  On Windows, we use
-   * {TracerId#getOsPidFromManagementFactory}, which depends on some
-   * undocumented features of the JVM, but which doesn't require a shell.
-   */
-  static long getOsPid() {
-    if ((System.getProperty("os.name", "generic").toLowerCase(Locale.ENGLISH)).
-        contains("windows")) {
-      return getOsPidFromManagementFactory();
-    } else {
-      return getOsPidFromShellPpid();
-    }
-  }
-
-  /**
-   * Get the process ID by executing a shell and printing the PPID (parent
-   * process ID).<p/>
-   *
-   * This method of getting the process ID doesn't depend on any undocumented
-   * features of the virtual machine, and should work on almost any UNIX
-   * operating system.
-   */
-  private static long getOsPidFromShellPpid() {
-    Process p = null;
-    StringBuilder sb = new StringBuilder();
-    try {
-      p = new ProcessBuilder("/usr/bin/env", "sh", "-c", "echo $PPID").
-        redirectErrorStream(true).start();
-      BufferedReader reader = new BufferedReader(
-          new InputStreamReader(p.getInputStream()));
-      String line = "";
-      while ((line = reader.readLine()) != null) {
-        sb.append(line.trim());
-      }
-      int exitVal = p.waitFor();
-      if (exitVal != 0) {
-        throw new IOException("Process exited with error code " +
-            Integer.valueOf(exitVal).toString());
-      }
-    } catch (InterruptedException e) {
-      LOG.error("Interrupted while getting operating system pid from " +
-          "the shell.", e);
-      return 0L;
-    } catch (IOException e) {
-      LOG.error("Error getting operating system pid from the shell.", e);
-      return 0L;
-    } finally {
-      if (p != null) {
-        p.destroy();
-      }
-    }
-    try {
-      return Long.parseLong(sb.toString());
-    } catch (NumberFormatException e) {
-      LOG.error("Error parsing operating system pid from the shell.", e);
-      return 0L;
-    }
-  }
-
-  /**
-   * Get the process ID by looking at the name of the managed bean for the
-   * runtime system of the Java virtual machine.<p/>
-   *
-   * Although this is undocumented, in the Oracle JVM this name is of the form
-   * [OS_PROCESS_ID]@[HOSTNAME].
-   */
-  private static long getOsPidFromManagementFactory() {
-    try {
-      return Long.parseLong(ManagementFactory.getRuntimeMXBean().
-          getName().split("@")[0]);
-    } catch (NumberFormatException e) {
-      LOG.error("Failed to get the operating system process ID from the name " +
-          "of the managed bean for the JVM.", e);
-      return 0L;
-    }
-  }
-
-  public String get() {
-    return tracerId;
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceCallable.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceCallable.java b/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceCallable.java
deleted file mode 100644
index e761fbf..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceCallable.java
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.wrappers;
-
-import org.apache.htrace.Span;
-import org.apache.htrace.Trace;
-import org.apache.htrace.TraceScope;
-
-import java.util.concurrent.Callable;
-
-/**
- * Wrap a Callable with a Span that survives a change in threads.
- */
-public class TraceCallable<V> implements Callable<V> {
-  private final Callable<V> impl;
-  private final Span parent;
-  private final String description;
-
-  public TraceCallable(Callable<V> impl) {
-    this(Trace.currentSpan(), impl);
-  }
-
-  public TraceCallable(Span parent, Callable<V> impl) {
-    this(parent, impl, null);
-  }
-
-  public TraceCallable(Span parent, Callable<V> impl, String description) {
-    this.impl = impl;
-    this.parent = parent;
-    this.description = description;
-  }
-
-  @Override
-  public V call() throws Exception {
-    if (parent != null) {
-      TraceScope chunk = Trace.startSpan(getDescription(), parent);
-
-      try {
-        return impl.call();
-      } finally {
-        chunk.close();
-      }
-    } else {
-      return impl.call();
-    }
-  }
-
-  public Callable<V> getImpl() {
-    return impl;
-  }
-
-  private String getDescription() {
-    return this.description == null ? Thread.currentThread().getName() : description;
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceExecutorService.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceExecutorService.java b/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceExecutorService.java
deleted file mode 100644
index 03e891f..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceExecutorService.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.wrappers;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-
-
-public class TraceExecutorService implements ExecutorService {
-
-  private final ExecutorService impl;
-
-  public TraceExecutorService(ExecutorService impl) {
-    this.impl = impl;
-  }
-
-  @Override
-  public void execute(Runnable command) {
-    impl.execute(new TraceRunnable(command));
-  }
-
-  @Override
-  public void shutdown() {
-    impl.shutdown();
-  }
-
-  @Override
-  public List<Runnable> shutdownNow() {
-    return impl.shutdownNow();
-  }
-
-  @Override
-  public boolean isShutdown() {
-    return impl.isShutdown();
-  }
-
-  @Override
-  public boolean isTerminated() {
-    return impl.isTerminated();
-  }
-
-  @Override
-  public boolean awaitTermination(long timeout, TimeUnit unit)
-      throws InterruptedException {
-    return impl.awaitTermination(timeout, unit);
-  }
-
-  @Override
-  public <T> Future<T> submit(Callable<T> task) {
-    return impl.submit(new TraceCallable<T>(task));
-  }
-
-  @Override
-  public <T> Future<T> submit(Runnable task, T result) {
-    return impl.submit(new TraceRunnable(task), result);
-  }
-
-  @Override
-  public Future<?> submit(Runnable task) {
-    return impl.submit(new TraceRunnable(task));
-  }
-
-  private <T> Collection<? extends Callable<T>> wrapCollection(
-      Collection<? extends Callable<T>> tasks) {
-    List<Callable<T>> result = new ArrayList<Callable<T>>();
-    for (Callable<T> task : tasks) {
-      result.add(new TraceCallable<T>(task));
-    }
-    return result;
-  }
-
-  @Override
-  public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)
-      throws InterruptedException {
-    return impl.invokeAll(wrapCollection(tasks));
-  }
-
-  @Override
-  public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks,
-                                       long timeout, TimeUnit unit) throws InterruptedException {
-    return impl.invokeAll(wrapCollection(tasks), timeout, unit);
-  }
-
-  @Override
-  public <T> T invokeAny(Collection<? extends Callable<T>> tasks)
-      throws InterruptedException, ExecutionException {
-    return impl.invokeAny(wrapCollection(tasks));
-  }
-
-  @Override
-  public <T> T invokeAny(Collection<? extends Callable<T>> tasks, long timeout,
-                         TimeUnit unit) throws InterruptedException, ExecutionException,
-      TimeoutException {
-    return impl.invokeAny(wrapCollection(tasks), timeout, unit);
-  }
-
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceProxy.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceProxy.java b/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceProxy.java
deleted file mode 100644
index c1aba29..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceProxy.java
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.wrappers;
-
-import org.apache.htrace.Sampler;
-import org.apache.htrace.Trace;
-import org.apache.htrace.TraceScope;
-
-import java.lang.reflect.InvocationHandler;
-import java.lang.reflect.Method;
-import java.lang.reflect.Proxy;
-
-public class TraceProxy {
-  /**
-   * Returns an object that will trace all calls to itself.
-   */
-  public static <T> T trace(T instance) {
-    return trace(instance, Sampler.ALWAYS);
-  }
-
-  /**
-   * Returns an object that will trace all calls to itself.
-   */
-  @SuppressWarnings("unchecked")
-  public static <T, V> T trace(final T instance, final Sampler sampler) {
-    InvocationHandler handler = new InvocationHandler() {
-      @Override
-      public Object invoke(Object obj, Method method, Object[] args)
-          throws Throwable {
-        if (!sampler.next()) {
-          return method.invoke(instance, args);
-        }
-
-        TraceScope scope = Trace.startSpan(method.getName(), Sampler.ALWAYS);
-        try {
-          return method.invoke(instance, args);
-        } catch (Throwable ex) {
-          ex.printStackTrace();
-          throw ex;
-        } finally {
-          scope.close();
-        }
-      }
-    };
-    return (T) Proxy.newProxyInstance(instance.getClass().getClassLoader(),
-        instance.getClass().getInterfaces(), handler);
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceRunnable.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceRunnable.java b/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceRunnable.java
deleted file mode 100644
index 6d370c8..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/wrappers/TraceRunnable.java
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace.wrappers;
-
-import org.apache.htrace.Span;
-import org.apache.htrace.Trace;
-import org.apache.htrace.TraceScope;
-
-/**
- * Wrap a Runnable with a Span that survives a change in threads.
- */
-public class TraceRunnable implements Runnable {
-
-  private final Span parent;
-  private final Runnable runnable;
-  private final String description;
-
-  public TraceRunnable(Runnable runnable) {
-    this(Trace.currentSpan(), runnable);
-  }
-
-  public TraceRunnable(Span parent, Runnable runnable) {
-    this(parent, runnable, null);
-  }
-
-  public TraceRunnable(Span parent, Runnable runnable, String description) {
-    this.parent = parent;
-    this.runnable = runnable;
-    this.description = description;
-  }
-
-  @Override
-  public void run() {
-    if (parent != null) {
-      TraceScope chunk = Trace.startSpan(getDescription(), parent);
-
-      try {
-        runnable.run();
-      } finally {
-        chunk.close();
-      }
-    } else {
-      runnable.run();
-    }
-  }
-
-  private String getDescription() {
-    return this.description == null ? Thread.currentThread().getName() : description;
-  }
-
-  public Runnable getRunnable() {
-    return runnable;
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/TestBadClient.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/TestBadClient.java b/htrace-core/src/test/java/org/apache/htrace/TestBadClient.java
deleted file mode 100644
index 868c0d0..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/TestBadClient.java
+++ /dev/null
@@ -1,154 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import static org.junit.Assert.assertThat;
-import static org.junit.Assert.assertTrue;
-import static org.hamcrest.CoreMatchers.containsString;
-
-import org.apache.htrace.HTraceConfiguration;
-import org.apache.htrace.Span;
-import org.apache.htrace.SpanReceiver;
-import org.apache.htrace.Tracer;
-import org.apache.htrace.impl.AlwaysSampler;
-import org.apache.htrace.impl.LocalFileSpanReceiver;
-import org.apache.htrace.impl.POJOSpanReceiver;
-import org.apache.htrace.impl.StandardOutSpanReceiver;
-import org.junit.After;
-import org.junit.Assert;
-import org.junit.Test;
-
-import java.io.File;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Map;
-
-public class TestBadClient {
-  /**
-   * Test closing an outer scope when an inner one is still active.
-   */
-  @Test
-  public void TestClosingOuterScope() throws Exception {
-    boolean gotException = false;
-    TraceScope outerScope = Trace.startSpan("outer", AlwaysSampler.INSTANCE);
-    TraceScope innerScope = Trace.startSpan("inner");
-    try {
-      outerScope.close();
-    } catch (RuntimeException e) {
-      assertThat(e.getMessage(),
-          containsString("You have probably forgotten to close or detach"));
-      gotException = true;
-    }
-    assertTrue("Expected to get exception because of improper " +
-        "scope closure.", gotException);
-    innerScope.close();
-  }
-
-  /**
-   * Test calling detach() two times on a scope object.
-   */
-  @Test
-  public void TestDoubleDetach() throws Exception {
-    boolean gotException = false;
-    TraceScope myScope = Trace.startSpan("myScope", AlwaysSampler.INSTANCE);
-    myScope.detach();
-    try {
-      myScope.detach();
-    } catch (RuntimeException e) {
-      assertThat(e.getMessage(),
-          containsString("it has already been detached."));
-      gotException = true;
-    }
-    assertTrue("Expected to get exception because of double TraceScope " +
-        "detach.", gotException);
-  }
-
-  private static class SpanHolder {
-    Span span;
-
-    void set(Span span) {
-      this.span = span;
-    }
-  }
-
-  /**
-   * Test correctly passing spans between threads using detach().
-   */
-  @Test
-  public void TestPassingSpanBetweenThreads() throws Exception {
-    final SpanHolder spanHolder = new SpanHolder();
-    Thread th = new Thread(new Runnable() {
-      @Override
-      public void run() {
-        TraceScope workerScope = Trace.startSpan("workerSpan",
-            AlwaysSampler.INSTANCE);
-        spanHolder.set(workerScope.getSpan());
-        workerScope.detach();
-      }
-    });
-    th.start();
-    th.join();
-
-    // Create new scope whose parent is the worker thread's span. 
-    TraceScope outermost = Trace.startSpan("outermost", spanHolder.span);
-    TraceScope nested = Trace.startSpan("nested");
-    nested.close();
-    outermost.close();
-    // Create another span which also descends from the worker thread's span.
-    TraceScope nested2 = Trace.startSpan("nested2", spanHolder.span);
-    nested2.close();
-
-    // Close the worker thread's span.
-    spanHolder.span.stop();
-
-    // We can create another descendant, even though the worker thread's span
-    // has been stopped.
-    TraceScope lateChildScope = Trace.startSpan("lateChild", spanHolder.span);
-    lateChildScope.close();
-  }
-
-  /**
-   * Test trying to manually set our TraceScope's parent in a case where there
-   * is a currently active span.
-   */
-  @Test
-  public void TestIncorrectStartSpan() throws Exception {
-    // Create new scope
-    TraceScope outermost = Trace.startSpan("outermost",
-        AlwaysSampler.INSTANCE);
-    // Create nested scope
-    TraceScope nested = Trace.startSpan("nested", outermost.getSpan()); 
-    // Error
-    boolean gotException = false;
-    try {
-      TraceScope error = Trace.startSpan("error", outermost.getSpan()); 
-      error.close();
-    } catch (RuntimeException e) {
-      assertThat(e.getMessage(),
-          containsString("there is already a currentSpan"));
-      gotException = true;
-    }
-    assertTrue("Expected to get exception because of incorrect startSpan.",
-        gotException);
-  }
-
-  @After
-  public void resetCurrentSpan() {
-    Tracer.getInstance().setCurrentSpan(null);
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/TestCountSampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/TestCountSampler.java b/htrace-core/src/test/java/org/apache/htrace/TestCountSampler.java
deleted file mode 100644
index 42ba4e2..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/TestCountSampler.java
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import org.apache.htrace.HTraceConfiguration;
-import org.apache.htrace.impl.CountSampler;
-import org.junit.Assert;
-import org.junit.Test;
-
-public class TestCountSampler {
-
-  @Test
-  public void testNext() {
-    CountSampler half = new CountSampler(HTraceConfiguration.
-        fromKeyValuePairs("sampler.frequency", "2"));
-    CountSampler hundred = new CountSampler(HTraceConfiguration.
-        fromKeyValuePairs("sampler.frequency", "100"));
-    int halfCount = 0;
-    int hundredCount = 0;
-    for (int i = 0; i < 200; i++) {
-      if (half.next())
-        halfCount++;
-      if (hundred.next())
-        hundredCount++;
-    }
-    Assert.assertEquals(2, hundredCount);
-    Assert.assertEquals(100, halfCount);
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/TestHTrace.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/TestHTrace.java b/htrace-core/src/test/java/org/apache/htrace/TestHTrace.java
deleted file mode 100644
index 92f96c8..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/TestHTrace.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import org.apache.htrace.TraceGraph.SpansByParent;
-import org.apache.htrace.impl.LocalFileSpanReceiver;
-import org.apache.htrace.impl.POJOSpanReceiver;
-import org.apache.htrace.impl.StandardOutSpanReceiver;
-import org.junit.Assert;
-import org.junit.Rule;
-import org.junit.Test;
-
-import java.io.File;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Map;
-
-public class TestHTrace {
-
-  @Rule
-  public TraceCreator traceCreator = new TraceCreator();
-
-  public static final String SPAN_FILE_FLAG = "spanFile";
-
-  /**
-   * Basic system test of HTrace.
-   *
-   * @throws Exception
-   */
-  @Test
-  public void testHtrace() throws Exception {
-    final int numTraces = 3;
-    String fileName = System.getProperty(SPAN_FILE_FLAG);
-
-    // writes spans to a file if one is provided to maven with
-    // -DspanFile="FILENAME", otherwise writes to standard out.
-    if (fileName != null) {
-      File f = new File(fileName);
-      File parent = f.getParentFile();
-      if (parent != null && !parent.exists() && !parent.mkdirs()) {
-        throw new IllegalArgumentException("Couldn't create file: "
-            + fileName);
-      }
-      HashMap<String, String> conf = new HashMap<String, String>();
-      conf.put("local-file-span-receiver.path", fileName);
-      LocalFileSpanReceiver receiver =
-          new LocalFileSpanReceiver(HTraceConfiguration.fromMap(conf));
-      traceCreator.addReceiver(receiver);
-    } else {
-      traceCreator.addReceiver(new StandardOutSpanReceiver(HTraceConfiguration.EMPTY));
-    }
-
-    traceCreator.addReceiver(new POJOSpanReceiver(HTraceConfiguration.EMPTY){
-      @Override
-      public void close() {
-        TraceGraph traceGraph = new TraceGraph(getSpans());
-        Collection<Span> roots = traceGraph.getSpansByParent().find(SpanId.INVALID);
-        Assert.assertTrue("Trace tree must have roots", !roots.isEmpty());
-        Assert.assertEquals(numTraces, roots.size());
-
-        Map<String, Span> descriptionToRootSpan = new HashMap<String, Span>();
-        for (Span root : roots) {
-          descriptionToRootSpan.put(root.getDescription(), root);
-        }
-
-        Assert.assertTrue(descriptionToRootSpan.keySet().contains(
-            TraceCreator.RPC_TRACE_ROOT));
-        Assert.assertTrue(descriptionToRootSpan.keySet().contains(
-            TraceCreator.SIMPLE_TRACE_ROOT));
-        Assert.assertTrue(descriptionToRootSpan.keySet().contains(
-            TraceCreator.THREADED_TRACE_ROOT));
-
-        SpansByParent spansByParentId = traceGraph.getSpansByParent();
-        Span rpcTraceRoot = descriptionToRootSpan.get(TraceCreator.RPC_TRACE_ROOT);
-        Assert.assertEquals(1, spansByParentId.find(rpcTraceRoot.getSpanId()).size());
-
-        Span rpcTraceChild1 = spansByParentId.find(rpcTraceRoot.getSpanId())
-            .iterator().next();
-        Assert.assertEquals(1, spansByParentId.find(rpcTraceChild1.getSpanId()).size());
-
-        Span rpcTraceChild2 = spansByParentId.find(rpcTraceChild1.getSpanId())
-            .iterator().next();
-        Assert.assertEquals(1, spansByParentId.find(rpcTraceChild2.getSpanId()).size());
-
-        Span rpcTraceChild3 = spansByParentId.find(rpcTraceChild2.getSpanId())
-            .iterator().next();
-        Assert.assertEquals(0, spansByParentId.find(rpcTraceChild3.getSpanId()).size());
-      }
-    });
-
-    traceCreator.createThreadedTrace();
-    traceCreator.createSimpleTrace();
-    traceCreator.createSampleRpcTrace();
-  }
-
-  @Test(timeout=60000)
-  public void testRootSpansHaveNonZeroSpanId() throws Exception {
-    TraceScope scope = Trace.startSpan("myRootSpan", new SpanId(100L, 200L));
-    Assert.assertNotNull(scope);
-    Assert.assertEquals("myRootSpan", scope.getSpan().getDescription());
-    Assert.assertEquals(100L, scope.getSpan().getSpanId().getHigh());
-    Assert.assertTrue(scope.getSpan().getSpanId().isValid());
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/TestHTraceConfiguration.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/TestHTraceConfiguration.java b/htrace-core/src/test/java/org/apache/htrace/TestHTraceConfiguration.java
deleted file mode 100644
index 440a826..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/TestHTraceConfiguration.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.htrace;
-
-import java.util.HashMap;
-import java.util.Map;
-
-import org.apache.htrace.HTraceConfiguration;
-import org.junit.Test;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-public class TestHTraceConfiguration {
-  @Test
-  public void testGetBoolean() throws Exception {
-
-    Map<String, String> m = new HashMap<String, String>();
-    m.put("testTrue", " True");
-    m.put("testFalse", "falsE ");
-    HTraceConfiguration configuration = HTraceConfiguration.fromMap(m);
-
-    // Tests for value being there
-    assertTrue(configuration.getBoolean("testTrue", false));
-    assertFalse(configuration.getBoolean("testFalse", true));
-
-    // Test for absent
-    assertTrue(configuration.getBoolean("absent", true));
-    assertFalse(configuration.getBoolean("absent", false));
-  }
-
-  @Test
-  public void testGetInt() throws Exception {
-    Map<String, String> m = new HashMap<String, String>();
-    m.put("a", "100");
-    m.put("b", "0");
-    m.put("c", "-100");
-    m.put("d", "5");
-
-    HTraceConfiguration configuration = HTraceConfiguration.fromMap(m);
-    assertEquals(100, configuration.getInt("a", -999));
-    assertEquals(0, configuration.getInt("b", -999));
-    assertEquals(-100, configuration.getInt("c", -999));
-    assertEquals(5, configuration.getInt("d", -999));
-    assertEquals(-999, configuration.getInt("absent", -999));
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/TestNullScope.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/TestNullScope.java b/htrace-core/src/test/java/org/apache/htrace/TestNullScope.java
deleted file mode 100644
index 26b1cba..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/TestNullScope.java
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import org.apache.htrace.Trace;
-import org.apache.htrace.TraceScope;
-import org.apache.htrace.NullScope;
-import org.junit.Assert;
-import org.junit.Test;
-
-public class TestNullScope {
-  @Test
-  public void testNullScope() {
-    Assert.assertTrue(!Trace.isTracing());
-    TraceScope tc = Trace.startSpan("NullScopeSingleton");
-    Assert.assertTrue(tc == NullScope.INSTANCE);
-    tc.detach();
-    tc.detach(); // should not fail even if called multiple times.
-    Assert.assertFalse(tc.isDetached());
-    tc.close();
-    tc.close(); // should not fail even if called multiple times.
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/TestSampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/TestSampler.java b/htrace-core/src/test/java/org/apache/htrace/TestSampler.java
deleted file mode 100644
index 7ff2e31..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/TestSampler.java
+++ /dev/null
@@ -1,59 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import java.util.HashMap;
-import java.util.Map;
-import org.apache.htrace.Sampler;
-import org.apache.htrace.Trace;
-import org.apache.htrace.TraceScope;
-import org.apache.htrace.impl.AlwaysSampler;
-import org.apache.htrace.impl.NeverSampler;
-import org.junit.Assert;
-import org.junit.Test;
-
-public class TestSampler {
-  @Test
-  public void testSamplerBuilder() {
-    Sampler alwaysSampler = new SamplerBuilder(
-        HTraceConfiguration.fromKeyValuePairs("sampler", "AlwaysSampler")).
-        build();
-    Assert.assertEquals(AlwaysSampler.class, alwaysSampler.getClass());
-
-    Sampler neverSampler = new SamplerBuilder(
-        HTraceConfiguration.fromKeyValuePairs("sampler", "NeverSampler")).
-        build();
-    Assert.assertEquals(NeverSampler.class, neverSampler.getClass());
-
-    Sampler neverSampler2 = new SamplerBuilder(HTraceConfiguration.
-        fromKeyValuePairs("sampler", "NonExistentSampler")).
-        build();
-    Assert.assertEquals(NeverSampler.class, neverSampler2.getClass());
-
-    Sampler neverSampler3 = new SamplerBuilder(HTraceConfiguration.
-        fromKeyValuePairs("sampler.is.not.defined", "NonExistentSampler")).
-        build();
-    Assert.assertEquals(NeverSampler.class, neverSampler3.getClass());
-  }
-
-  @Test
-  public void testAlwaysSampler() {
-    TraceScope cur = Trace.startSpan("test");
-    Assert.assertNotNull(cur);
-    cur.close();
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/TestSpanId.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/TestSpanId.java b/htrace-core/src/test/java/org/apache/htrace/TestSpanId.java
deleted file mode 100644
index 10e6cca..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/TestSpanId.java
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import java.util.Random;
-import org.apache.htrace.SpanId;
-import org.junit.Assert;
-import org.junit.Test;
-
-public class TestSpanId {
-  private void testRoundTrip(SpanId id) throws Exception {
-    String str = id.toString();
-    SpanId id2 = SpanId.fromString(str);
-    Assert.assertEquals(id, id2);
-  }
-
-  @Test
-  public void testToStringAndFromString() throws Exception {
-    testRoundTrip(SpanId.INVALID);
-    testRoundTrip(new SpanId(0x1234567812345678L, 0x1234567812345678L));
-    testRoundTrip(new SpanId(0xf234567812345678L, 0xf234567812345678L));
-    testRoundTrip(new SpanId(0xffffffffffffffffL, 0xffffffffffffffffL));
-    Random rand = new Random(12345);
-    for (int i = 0; i < 100; i++) {
-      testRoundTrip(new SpanId(rand.nextLong(), rand.nextLong()));
-    }
-  }
-
-  @Test
-  public void testValidAndInvalidIds() throws Exception {
-    Assert.assertFalse(SpanId.INVALID.isValid());
-    Assert.assertTrue(
-        new SpanId(0x1234567812345678L, 0x1234567812345678L).isValid());
-    Assert.assertTrue(
-        new SpanId(0xf234567812345678L, 0xf234567812345678L).isValid());
-  }
-
-  private void expectLessThan(SpanId a, SpanId b) throws Exception {
-    int cmp = a.compareTo(b);
-    Assert.assertTrue("Expected " + a + " to be less than " + b,
-        (cmp < 0));
-    int cmp2 = b.compareTo(a);
-    Assert.assertTrue("Expected " + b + " to be greater than " + a,
-        (cmp2 > 0));
-  }
-
-  @Test
-  public void testIdComparisons() throws Exception {
-    expectLessThan(new SpanId(0x0000000000000001L, 0x0000000000000001L),
-                   new SpanId(0x0000000000000001L, 0x0000000000000002L));
-    expectLessThan(new SpanId(0x0000000000000001L, 0x0000000000000001L),
-                   new SpanId(0x0000000000000002L, 0x0000000000000000L));
-    expectLessThan(SpanId.INVALID,
-                   new SpanId(0xffffffffffffffffL, 0xffffffffffffffffL));
-    expectLessThan(new SpanId(0x1234567812345678L, 0x1234567812345678L),
-                   new SpanId(0x1234567812345678L, 0xf234567812345678L));
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/TestSpanReceiverBuilder.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/TestSpanReceiverBuilder.java b/htrace-core/src/test/java/org/apache/htrace/TestSpanReceiverBuilder.java
deleted file mode 100644
index 750142b..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/TestSpanReceiverBuilder.java
+++ /dev/null
@@ -1,140 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.htrace.impl.LocalFileSpanReceiver;
-import org.junit.Assert;
-import org.junit.Test;
-
-import java.io.File;
-import java.io.IOException;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.UUID;
-
-public class TestSpanReceiverBuilder {
-  private static final Log LOG =
-      LogFactory.getLog(TestSpanReceiverBuilder.class);
-
-  /**
-   * Test that if no span receiver is configured, the builder returns null.
-   */
-  @Test
-  public void testGetNullSpanReceiver() {
-    SpanReceiverBuilder builder =
-        new SpanReceiverBuilder(HTraceConfiguration.EMPTY).logErrors(false);
-    SpanReceiver rcvr = builder.build();
-    Assert.assertEquals(null, rcvr);
-  }
-
-  private static SpanReceiver createSpanReceiver(Map<String, String> m) {
-    HTraceConfiguration hconf = HTraceConfiguration.fromMap(m);
-    SpanReceiverBuilder builder =
-        new SpanReceiverBuilder(hconf).
-            logErrors(false);
-    return builder.build();
-  }
-
-  private static final File TMPDIR =
-      new File(System.getProperty("java.io.tmpdir"));
-
-  /**
-   * Test getting various SpanReceiver objects.
-   */
-  @Test
-  public void testGetSpanReceivers() throws Exception {
-    HashMap<String, String> confMap = new HashMap<String, String>();
-
-    // Create LocalFileSpanReceiver
-    File testFile = new File(TMPDIR, UUID.randomUUID().toString());
-    try {
-      confMap.put(LocalFileSpanReceiver.PATH_KEY, testFile.getAbsolutePath());
-      confMap.put(SpanReceiverBuilder.SPAN_RECEIVER_CONF_KEY,
-          "org.apache.htrace.impl.LocalFileSpanReceiver");
-      SpanReceiver rcvr = createSpanReceiver(confMap);
-      Assert.assertNotNull(rcvr);
-      Assert.assertEquals("org.apache.htrace.impl.LocalFileSpanReceiver",
-          rcvr.getClass().getName());
-      rcvr.close();
-    } finally {
-      if (!testFile.delete()) {
-        LOG.debug("failed to delete " + testFile); // keep findbugs happy
-      }
-    }
-
-    // Create POJOSpanReceiver
-    confMap.remove(LocalFileSpanReceiver.PATH_KEY);
-    confMap.put(SpanReceiverBuilder.SPAN_RECEIVER_CONF_KEY, "POJOSpanReceiver");
-    SpanReceiver rcvr = createSpanReceiver(confMap);
-    Assert.assertEquals("org.apache.htrace.impl.POJOSpanReceiver",
-        rcvr.getClass().getName());
-    rcvr.close();
-
-    // Create StandardOutSpanReceiver
-    confMap.remove(LocalFileSpanReceiver.PATH_KEY);
-    confMap.put(SpanReceiverBuilder.SPAN_RECEIVER_CONF_KEY,
-        "org.apache.htrace.impl.StandardOutSpanReceiver");
-    rcvr = createSpanReceiver(confMap);
-    Assert.assertEquals("org.apache.htrace.impl.StandardOutSpanReceiver",
-        rcvr.getClass().getName());
-    rcvr.close();
-  }
-
-  public static class TestSpanReceiver implements SpanReceiver {
-    final static String SUCCEEDS = "test.span.receiver.succeeds";
-
-    public TestSpanReceiver(HTraceConfiguration conf) {
-      if (conf.get(SUCCEEDS) == null) {
-        throw new RuntimeException("Can't create TestSpanReceiver: " +
-            "invalid configuration.");
-      }
-    }
-
-    @Override
-    public void receiveSpan(Span span) {
-    }
-
-    @Override
-    public void close() throws IOException {
-    }
-  }
-
-  /**
-   * Test trying to create a SpanReceiver that experiences an error in the
-   * constructor.
-   */
-  @Test
-  public void testGetSpanReceiverWithConstructorError() throws Exception {
-    HashMap<String, String> confMap = new HashMap<String, String>();
-
-    // Create TestSpanReceiver
-    confMap.put(SpanReceiverBuilder.SPAN_RECEIVER_CONF_KEY,
-        TestSpanReceiver.class.getName());
-    confMap.put(TestSpanReceiver.SUCCEEDS, "true");
-    SpanReceiver rcvr = createSpanReceiver(confMap);
-    Assert.assertEquals(TestSpanReceiver.class.getName(),
-        rcvr.getClass().getName());
-    rcvr.close();
-
-    // Fail to create TestSpanReceiver
-    confMap.remove(TestSpanReceiver.SUCCEEDS);
-    rcvr = createSpanReceiver(confMap);
-    Assert.assertEquals(null, rcvr);
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/TraceCreator.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/TraceCreator.java b/htrace-core/src/test/java/org/apache/htrace/TraceCreator.java
deleted file mode 100644
index 565ba05..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/TraceCreator.java
+++ /dev/null
@@ -1,169 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import org.junit.rules.TestRule;
-import org.junit.runner.Description;
-import org.junit.runners.model.Statement;
-
-import java.util.Collection;
-import java.util.Random;
-import java.util.concurrent.ThreadLocalRandom;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Random;
-
-/**
- * Does some stuff and traces it.
- */
-public class TraceCreator implements TestRule {
-  private final List<SpanReceiver> receivers = new ArrayList<SpanReceiver>();
-
-  public static final String RPC_TRACE_ROOT = "createSampleRpcTrace";
-  public static final String THREADED_TRACE_ROOT = "createThreadedTrace";
-  public static final String SIMPLE_TRACE_ROOT = "createSimpleTrace";
-
-  public TraceCreator addReceiver(SpanReceiver receiver) {
-    Trace.addReceiver(receiver);
-    this.receivers.add(receiver);
-    return this;
-  }
-
-  @Override
-  public Statement apply(final Statement base, Description description) {
-    return new Statement() {
-      @Override
-      public void evaluate() throws Throwable {
-        try {
-          base.evaluate();
-          for (SpanReceiver receiver : receivers) {
-            receiver.close();
-          }
-        } finally {
-          for (SpanReceiver receiver : receivers) {
-            Trace.removeReceiver(receiver);
-          }
-        }
-      }
-    };
-  }
-
-  public void createSampleRpcTrace() {
-    TraceScope s = Trace.startSpan(RPC_TRACE_ROOT, Sampler.ALWAYS);
-    try {
-      pretendRpcSend();
-    } finally {
-      s.close();
-    }
-  }
-
-  public void createSimpleTrace() {
-    TraceScope s = Trace.startSpan(SIMPLE_TRACE_ROOT, Sampler.ALWAYS);
-    try {
-      importantWork1();
-    } finally {
-      s.close();
-    }
-  }
-
-  /**
-   * Creates the demo trace (will create different traces from call to call).
-   */
-  public void createThreadedTrace() {
-    TraceScope s = Trace.startSpan(THREADED_TRACE_ROOT, Sampler.ALWAYS);
-    try {
-      Random r = ThreadLocalRandom.current();
-      int numThreads = r.nextInt(4) + 1;
-      Thread[] threads = new Thread[numThreads];
-
-      for (int i = 0; i < numThreads; i++) {
-        threads[i] = new Thread(Trace.wrap(new MyRunnable()));
-      }
-      for (int i = 0; i < numThreads; i++) {
-        threads[i].start();
-      }
-      for (int i = 0; i < numThreads; i++) {
-        try {
-          threads[i].join();
-        } catch (InterruptedException e) {
-        }
-      }
-      importantWork1();
-    } finally {
-      s.close();
-    }
-  }
-
-  private void importantWork1() {
-    TraceScope cur = Trace.startSpan("important work 1");
-    try {
-      Thread.sleep((long) (2000 * Math.random()));
-      importantWork2();
-    } catch (InterruptedException e) {
-      Thread.currentThread().interrupt();
-    } finally {
-      cur.close();
-    }
-  }
-
-  private void importantWork2() {
-    TraceScope cur = Trace.startSpan("important work 2");
-    try {
-      Thread.sleep((long) (2000 * Math.random()));
-    } catch (InterruptedException e) {
-      Thread.currentThread().interrupt();
-    } finally {
-      cur.close();
-    }
-  }
-
-  private class MyRunnable implements Runnable {
-    @Override
-    public void run() {
-      try {
-        Thread.sleep(750);
-        Random r = ThreadLocalRandom.current();
-        int importantNumber = 100 / r.nextInt(3);
-        System.out.println("Important number: " + importantNumber);
-      } catch (InterruptedException ie) {
-        Thread.currentThread().interrupt();
-      } catch (ArithmeticException ae) {
-        TraceScope c = Trace.startSpan("dealing with arithmetic exception.");
-        try {
-          Thread.sleep((long) (3000 * Math.random()));
-        } catch (InterruptedException ie1) {
-          Thread.currentThread().interrupt();
-        } finally {
-          c.close();
-        }
-      }
-    }
-  }
-
-  public void pretendRpcSend() {
-    pretendRpcReceiveWithTraceInfo(Trace.currentSpan());
-  }
-
-  public void pretendRpcReceiveWithTraceInfo(Span parent) {
-    TraceScope s = Trace.startSpan("received RPC", parent);
-    try {
-      importantWork1();
-    } finally {
-      s.close();
-    }
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/TraceGraph.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/TraceGraph.java b/htrace-core/src/test/java/org/apache/htrace/TraceGraph.java
deleted file mode 100644
index 9004ea6..0000000
--- a/htrace-core/src/test/java/org/apache/htrace/TraceGraph.java
+++ /dev/null
@@ -1,179 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import org.apache.htrace.impl.MilliSpan;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-
-import java.util.Arrays;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.TreeSet;
-
-/**
- * Used to create the graph formed by spans.
- */
-public class TraceGraph {
-  private static final Log LOG = LogFactory.getLog(Tracer.class);
-
-
-  public static class SpansByParent {
-    /**
-     * Compare two spans by span ID.
-     */
-    private static Comparator<Span> COMPARATOR =
-        new Comparator<Span>() {
-          @Override
-          public int compare(Span a, Span b) {
-            return a.getSpanId().compareTo(b.getSpanId());
-          }
-        };
-
-    private final TreeSet<Span> treeSet;
-
-    private final HashMap<SpanId, LinkedList<Span>> parentToSpans;
-
-    SpansByParent(Collection<Span> spans) {
-      TreeSet<Span> treeSet = new TreeSet<Span>(COMPARATOR);
-      parentToSpans = new HashMap<SpanId, LinkedList<Span>>();
-      for (Span span : spans) {
-        treeSet.add(span);
-        for (SpanId parent : span.getParents()) {
-          LinkedList<Span> list = parentToSpans.get(parent);
-          if (list == null) {
-            list = new LinkedList<Span>();
-            parentToSpans.put(parent, list);
-          }
-          list.add(span);
-        }
-        if (span.getParents().length == 0) {
-          LinkedList<Span> list = parentToSpans.get(SpanId.INVALID);
-          if (list == null) {
-            list = new LinkedList<Span>();
-            parentToSpans.put(SpanId.INVALID, list);
-          }
-          list.add(span);
-        }
-      }
-      this.treeSet = treeSet;
-    }
-
-    public List<Span> find(SpanId parentId) {
-      LinkedList<Span> spans = parentToSpans.get(parentId);
-      if (spans == null) {
-        return new LinkedList<Span>();
-      }
-      return spans;
-    }
-
-    public Iterator<Span> iterator() {
-      return Collections.unmodifiableSortedSet(treeSet).iterator();
-    }
-  }
-
-  public static class SpansByTracerId {
-    /**
-     * Compare two spans by process ID, and then by span ID.
-     */
-    private static Comparator<Span> COMPARATOR =
-        new Comparator<Span>() {
-          @Override
-          public int compare(Span a, Span b) {
-            int cmp = a.getTracerId().compareTo(b.getTracerId());
-            if (cmp != 0) {
-              return cmp;
-            }
-            return a.getSpanId().compareTo(b.getSpanId());
-          }
-        };
-
-    private final TreeSet<Span> treeSet;
-
-    SpansByTracerId(Collection<Span> spans) {
-      TreeSet<Span> treeSet = new TreeSet<Span>(COMPARATOR);
-      for (Span span : spans) {
-        treeSet.add(span);
-      }
-      this.treeSet = treeSet;
-    }
-
-    public List<Span> find(String tracerId) {
-      List<Span> spans = new ArrayList<Span>();
-      Span span = new MilliSpan.Builder().
-                    spanId(SpanId.INVALID).
-                    tracerId(tracerId).
-                    build();
-      while (true) {
-        span = treeSet.higher(span);
-        if (span == null) {
-          break;
-        }
-        if (span.getTracerId().equals(tracerId)) {
-          break;
-        }
-        spans.add(span);
-      }
-      return spans;
-    }
-
-    public Iterator<Span> iterator() {
-      return Collections.unmodifiableSortedSet(treeSet).iterator();
-    }
-  }
-
-  private final SpansByParent spansByParent;
-  private final SpansByTracerId spansByTracerId;
-
-  /**
-   * Create a new TraceGraph
-   *
-   * @param spans The collection of spans to use to create this TraceGraph. Should
-   *              have at least one root span.
-   */
-  public TraceGraph(Collection<Span> spans) {
-    this.spansByParent = new SpansByParent(spans);
-    this.spansByTracerId = new SpansByTracerId(spans);
-  }
-
-  public SpansByParent getSpansByParent() {
-    return spansByParent;
-  }
-
-  public SpansByTracerId getSpansByTracerId() {
-    return spansByTracerId;
-  }
-
-  @Override
-  public String toString() {
-    StringBuilder bld = new StringBuilder();
-    String prefix = "";
-    for (Iterator<Span> iter = spansByParent.iterator(); iter.hasNext();) {
-      Span span = iter.next();
-      bld.append(prefix).append(span.toString());
-      prefix = "\n";
-    }
-    return bld.toString();
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/test/java/org/apache/htrace/core/TestBadClient.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/test/java/org/apache/htrace/core/TestBadClient.java b/htrace-core/src/test/java/org/apache/htrace/core/TestBadClient.java
new file mode 100644
index 0000000..54de21b
--- /dev/null
+++ b/htrace-core/src/test/java/org/apache/htrace/core/TestBadClient.java
@@ -0,0 +1,146 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+import static org.hamcrest.CoreMatchers.containsString;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.File;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+
+public class TestBadClient {
+  /**
+   * Test closing an outer scope when an inner one is still active.
+   */
+  @Test
+  public void TestClosingOuterScope() throws Exception {
+    boolean gotException = false;
+    TraceScope outerScope = Trace.startSpan("outer", AlwaysSampler.INSTANCE);
+    TraceScope innerScope = Trace.startSpan("inner");
+    try {
+      outerScope.close();
+    } catch (RuntimeException e) {
+      assertThat(e.getMessage(),
+          containsString("You have probably forgotten to close or detach"));
+      gotException = true;
+    }
+    assertTrue("Expected to get exception because of improper " +
+        "scope closure.", gotException);
+    innerScope.close();
+  }
+
+  /**
+   * Test calling detach() two times on a scope object.
+   */
+  @Test
+  public void TestDoubleDetach() throws Exception {
+    boolean gotException = false;
+    TraceScope myScope = Trace.startSpan("myScope", AlwaysSampler.INSTANCE);
+    myScope.detach();
+    try {
+      myScope.detach();
+    } catch (RuntimeException e) {
+      assertThat(e.getMessage(),
+          containsString("it has already been detached."));
+      gotException = true;
+    }
+    assertTrue("Expected to get exception because of double TraceScope " +
+        "detach.", gotException);
+  }
+
+  private static class SpanHolder {
+    Span span;
+
+    void set(Span span) {
+      this.span = span;
+    }
+  }
+
+  /**
+   * Test correctly passing spans between threads using detach().
+   */
+  @Test
+  public void TestPassingSpanBetweenThreads() throws Exception {
+    final SpanHolder spanHolder = new SpanHolder();
+    Thread th = new Thread(new Runnable() {
+      @Override
+      public void run() {
+        TraceScope workerScope = Trace.startSpan("workerSpan",
+            AlwaysSampler.INSTANCE);
+        spanHolder.set(workerScope.getSpan());
+        workerScope.detach();
+      }
+    });
+    th.start();
+    th.join();
+
+    // Create new scope whose parent is the worker thread's span. 
+    TraceScope outermost = Trace.startSpan("outermost", spanHolder.span);
+    TraceScope nested = Trace.startSpan("nested");
+    nested.close();
+    outermost.close();
+    // Create another span which also descends from the worker thread's span.
+    TraceScope nested2 = Trace.startSpan("nested2", spanHolder.span);
+    nested2.close();
+
+    // Close the worker thread's span.
+    spanHolder.span.stop();
+
+    // We can create another descendant, even though the worker thread's span
+    // has been stopped.
+    TraceScope lateChildScope = Trace.startSpan("lateChild", spanHolder.span);
+    lateChildScope.close();
+  }
+
+  /**
+   * Test trying to manually set our TraceScope's parent in a case where there
+   * is a currently active span.
+   */
+  @Test
+  public void TestIncorrectStartSpan() throws Exception {
+    // Create new scope
+    TraceScope outermost = Trace.startSpan("outermost",
+        AlwaysSampler.INSTANCE);
+    // Create nested scope
+    TraceScope nested = Trace.startSpan("nested", outermost.getSpan()); 
+    // Error
+    boolean gotException = false;
+    try {
+      TraceScope error = Trace.startSpan("error", outermost.getSpan()); 
+      error.close();
+    } catch (RuntimeException e) {
+      assertThat(e.getMessage(),
+          containsString("there is already a currentSpan"));
+      gotException = true;
+    }
+    assertTrue("Expected to get exception because of incorrect startSpan.",
+        gotException);
+  }
+
+  @After
+  public void resetCurrentSpan() {
+    Tracer.getInstance().setCurrentSpan(null);
+  }
+}



[4/4] incubator-htrace git commit: HTRACE-211. Move htrace-core classes to the org.apache.htrace.core namespace (cmccabe)

Posted by cm...@apache.org.
HTRACE-211. Move htrace-core classes to the org.apache.htrace.core namespace (cmccabe)


Project: http://git-wip-us.apache.org/repos/asf/incubator-htrace/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-htrace/commit/fd889b65
Tree: http://git-wip-us.apache.org/repos/asf/incubator-htrace/tree/fd889b65
Diff: http://git-wip-us.apache.org/repos/asf/incubator-htrace/diff/fd889b65

Branch: refs/heads/master
Commit: fd889b659604c227045200fce4fd8eadf85e7166
Parents: afa0b71
Author: Colin P. Mccabe <cm...@apache.org>
Authored: Tue Aug 18 11:03:37 2015 -0700
Committer: Colin P. Mccabe <cm...@apache.org>
Committed: Tue Aug 18 11:13:10 2015 -0700

----------------------------------------------------------------------
 .../org/apache/htrace/HTraceConfiguration.java  | 109 ------
 .../main/java/org/apache/htrace/NullScope.java  |  44 ---
 .../main/java/org/apache/htrace/Sampler.java    |  42 ---
 .../java/org/apache/htrace/SamplerBuilder.java  |  92 -----
 .../src/main/java/org/apache/htrace/Span.java   | 192 ----------
 .../src/main/java/org/apache/htrace/SpanId.java | 149 --------
 .../java/org/apache/htrace/SpanReceiver.java    |  39 --
 .../org/apache/htrace/SpanReceiverBuilder.java  | 138 --------
 .../org/apache/htrace/TimelineAnnotation.java   |  40 ---
 .../src/main/java/org/apache/htrace/Trace.java  | 223 ------------
 .../main/java/org/apache/htrace/TraceScope.java |  99 ------
 .../src/main/java/org/apache/htrace/Tracer.java | 130 -------
 .../org/apache/htrace/core/AlwaysSampler.java   |  33 ++
 .../org/apache/htrace/core/CountSampler.java    |  39 ++
 .../apache/htrace/core/HTraceConfiguration.java | 109 ++++++
 .../htrace/core/LocalFileSpanReceiver.java      | 261 ++++++++++++++
 .../java/org/apache/htrace/core/MilliSpan.java  | 348 ++++++++++++++++++
 .../org/apache/htrace/core/NeverSampler.java    |  34 ++
 .../java/org/apache/htrace/core/NullScope.java  |  44 +++
 .../apache/htrace/core/POJOSpanReceiver.java    |  49 +++
 .../apache/htrace/core/ProbabilitySampler.java  |  46 +++
 .../java/org/apache/htrace/core/Sampler.java    |  39 ++
 .../org/apache/htrace/core/SamplerBuilder.java  |  91 +++++
 .../main/java/org/apache/htrace/core/Span.java  | 192 ++++++++++
 .../java/org/apache/htrace/core/SpanId.java     | 149 ++++++++
 .../org/apache/htrace/core/SpanReceiver.java    |  39 ++
 .../apache/htrace/core/SpanReceiverBuilder.java | 138 ++++++++
 .../htrace/core/StandardOutSpanReceiver.java    |  42 +++
 .../apache/htrace/core/TimelineAnnotation.java  |  40 +++
 .../main/java/org/apache/htrace/core/Trace.java | 219 ++++++++++++
 .../org/apache/htrace/core/TraceCallable.java   |  65 ++++
 .../htrace/core/TraceExecutorService.java       | 118 +++++++
 .../java/org/apache/htrace/core/TraceProxy.java |  58 +++
 .../org/apache/htrace/core/TraceRunnable.java   |  64 ++++
 .../java/org/apache/htrace/core/TraceScope.java |  99 ++++++
 .../java/org/apache/htrace/core/Tracer.java     | 129 +++++++
 .../java/org/apache/htrace/core/TracerId.java   | 290 +++++++++++++++
 .../org/apache/htrace/impl/AlwaysSampler.java   |  36 --
 .../org/apache/htrace/impl/CountSampler.java    |  43 ---
 .../htrace/impl/LocalFileSpanReceiver.java      | 264 --------------
 .../java/org/apache/htrace/impl/MilliSpan.java  | 352 -------------------
 .../org/apache/htrace/impl/NeverSampler.java    |  37 --
 .../apache/htrace/impl/POJOSpanReceiver.java    |  53 ---
 .../apache/htrace/impl/ProbabilitySampler.java  |  48 ---
 .../htrace/impl/StandardOutSpanReceiver.java    |  45 ---
 .../java/org/apache/htrace/impl/TracerId.java   | 291 ---------------
 .../apache/htrace/wrappers/TraceCallable.java   |  69 ----
 .../htrace/wrappers/TraceExecutorService.java   | 118 -------
 .../org/apache/htrace/wrappers/TraceProxy.java  |  62 ----
 .../apache/htrace/wrappers/TraceRunnable.java   |  68 ----
 .../java/org/apache/htrace/TestBadClient.java   | 154 --------
 .../org/apache/htrace/TestCountSampler.java     |  43 ---
 .../test/java/org/apache/htrace/TestHTrace.java | 118 -------
 .../apache/htrace/TestHTraceConfiguration.java  |  63 ----
 .../java/org/apache/htrace/TestNullScope.java   |  37 --
 .../java/org/apache/htrace/TestSampler.java     |  59 ----
 .../test/java/org/apache/htrace/TestSpanId.java |  72 ----
 .../apache/htrace/TestSpanReceiverBuilder.java  | 140 --------
 .../java/org/apache/htrace/TraceCreator.java    | 169 ---------
 .../test/java/org/apache/htrace/TraceGraph.java | 179 ----------
 .../org/apache/htrace/core/TestBadClient.java   | 146 ++++++++
 .../apache/htrace/core/TestCountSampler.java    |  41 +++
 .../java/org/apache/htrace/core/TestHTrace.java | 116 ++++++
 .../htrace/core/TestHTraceConfiguration.java    |  62 ++++
 .../htrace/core/TestLocalFileSpanReceiver.java  |  70 ++++
 .../org/apache/htrace/core/TestMilliSpan.java   | 145 ++++++++
 .../org/apache/htrace/core/TestNullScope.java   |  34 ++
 .../org/apache/htrace/core/TestSampler.java     |  55 +++
 .../java/org/apache/htrace/core/TestSpanId.java |  72 ++++
 .../htrace/core/TestSpanReceiverBuilder.java    | 139 ++++++++
 .../org/apache/htrace/core/TestTracerId.java    |  47 +++
 .../org/apache/htrace/core/TraceCreator.java    | 169 +++++++++
 .../java/org/apache/htrace/core/TraceGraph.java | 176 ++++++++++
 .../htrace/impl/TestLocalFileSpanReceiver.java  |  75 ----
 .../org/apache/htrace/impl/TestMilliSpan.java   | 148 --------
 .../org/apache/htrace/impl/TestTracerId.java    |  47 ---
 76 files changed, 4007 insertions(+), 4087 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/HTraceConfiguration.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/HTraceConfiguration.java b/htrace-core/src/main/java/org/apache/htrace/HTraceConfiguration.java
deleted file mode 100644
index 4580dff..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/HTraceConfiguration.java
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-
-import java.util.HashMap;
-import java.util.Map;
-
-/**
- * Wrapper which integrating applications should implement in order
- * to provide tracing configuration.
- */
-public abstract class HTraceConfiguration {
-
-  private static final Log LOG = LogFactory.getLog(HTraceConfiguration.class);
-
-  private static final Map<String, String> EMPTY_MAP = new HashMap<String, String>(1);
-
-  /**
-   * An empty HTrace configuration.
-   */
-  public static final HTraceConfiguration EMPTY = fromMap(EMPTY_MAP);
-
-  /**
-   * Create an HTrace configuration from a map.
-   *
-   * @param conf    The map to create the configuration from.
-   * @return        The new configuration.
-   */
-  public static HTraceConfiguration fromMap(Map<String, String> conf) {
-    return new MapConf(conf);
-  }
-
-  public static HTraceConfiguration fromKeyValuePairs(String... pairs) {
-    if ((pairs.length % 2) != 0) {
-      throw new RuntimeException("You must specify an equal number of keys " +
-          "and values.");
-    }
-    Map<String, String> conf = new HashMap<String, String>();
-    for (int i = 0; i < pairs.length; i+=2) {
-      conf.put(pairs[i], pairs[i + 1]);
-    }
-    return new MapConf(conf);
-  }
-
-  public abstract String get(String key);
-
-  public abstract String get(String key, String defaultValue);
-
-  public boolean getBoolean(String key, boolean defaultValue) {
-    String value = get(key, String.valueOf(defaultValue)).trim().toLowerCase();
-
-    if ("true".equals(value)) {
-      return true;
-    } else if ("false".equals(value)) {
-      return false;
-    }
-
-    LOG.warn("Expected boolean for key [" + key + "] instead got [" + value + "].");
-    return defaultValue;
-  }
-
-  public int getInt(String key, int defaultVal) {
-    String val = get(key);
-    if (val == null || val.trim().isEmpty()) {
-      return defaultVal;
-    }
-    try {
-      return Integer.parseInt(val);
-    } catch (NumberFormatException nfe) {
-      throw new IllegalArgumentException("Bad value for '" + key + "': should be int");
-    }
-  }
-
-  private static class MapConf extends HTraceConfiguration {
-    private final Map<String, String> conf;
-
-    public MapConf(Map<String, String> conf) {
-      this.conf = new HashMap<String, String>(conf);
-    }
-
-    @Override
-    public String get(String key) {
-      return conf.get(key);
-    }
-
-    @Override
-    public String get(String key, String defaultValue) {
-      String value = get(key);
-      return value == null ? defaultValue : value;
-    }
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/NullScope.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/NullScope.java b/htrace-core/src/main/java/org/apache/htrace/NullScope.java
deleted file mode 100644
index ff9a42c..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/NullScope.java
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-/**
- * Singleton instance representing an empty {@link TraceScope}.
- */
-public final class NullScope extends TraceScope {
-
-  public static final TraceScope INSTANCE = new NullScope();
-
-  private NullScope() {
-    super(null, null);
-  }
-
-  @Override
-  public Span detach() {
-    return null;
-  }
-
-  @Override
-  public void close() {
-    return;
-  }
-
-  @Override
-  public String toString() {
-    return "NullScope";
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/Sampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/Sampler.java b/htrace-core/src/main/java/org/apache/htrace/Sampler.java
deleted file mode 100644
index 3bf62aa..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/Sampler.java
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import org.apache.htrace.impl.AlwaysSampler;
-import org.apache.htrace.impl.NeverSampler;
-
-/**
- * Extremely simple callback to determine the frequency that an action should be
- * performed.
- * <p/>
- * For example, the next() function may look like this:
- * <p/>
- * <pre>
- * <code>
- * public boolean next() {
- *   return Math.random() &gt; 0.5;
- * }
- * </code>
- * </pre>
- * This would trace 50% of all gets, 75% of all puts and would not trace any other requests.
- */
-public interface Sampler {
-  public static final Sampler ALWAYS = AlwaysSampler.INSTANCE;
-  public static final Sampler NEVER = NeverSampler.INSTANCE;
-
-  public boolean next();
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/SamplerBuilder.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/SamplerBuilder.java b/htrace-core/src/main/java/org/apache/htrace/SamplerBuilder.java
deleted file mode 100644
index 4364671..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/SamplerBuilder.java
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import java.lang.reflect.Constructor;
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.htrace.impl.AlwaysSampler;
-import org.apache.htrace.impl.NeverSampler;
-
-/**
- * A {@link Sampler} builder. It reads a {@link Sampler} class name from the provided
- * configuration using the {@link #SAMPLER_CONF_KEY} key. Unqualified class names
- * are interpreted as members of the {@code org.apache.htrace.impl} package. The {@link #build()}
- * method constructs an instance of that class, initialized with the same configuration.
- */
-public class SamplerBuilder {
-
-  // TODO: should follow the same API as SpanReceiverBuilder
-
-  public final static String SAMPLER_CONF_KEY = "sampler";
-  private final static String DEFAULT_PACKAGE = "org.apache.htrace.impl";
-  private final static ClassLoader classLoader =
-      SamplerBuilder.class.getClassLoader();
-  private final HTraceConfiguration conf;
-  private static final Log LOG = LogFactory.getLog(SamplerBuilder.class);
-
-  public SamplerBuilder(HTraceConfiguration conf) {
-    this.conf = conf;
-  }
-
-  public Sampler build() {
-    Sampler sampler = newSampler();
-    if (LOG.isTraceEnabled()) {
-      LOG.trace("Created new sampler of type " +
-          sampler.getClass().getName(), new Exception());
-    }
-    return sampler;
-  }
-
-  private Sampler newSampler() {
-    String str = conf.get(SAMPLER_CONF_KEY);
-    if (str == null || str.isEmpty()) {
-      return NeverSampler.INSTANCE;
-    }
-    if (!str.contains(".")) {
-      str = DEFAULT_PACKAGE + "." + str;
-    }
-    Class cls = null;
-    try {
-      cls = classLoader.loadClass(str);
-    } catch (ClassNotFoundException e) {
-      LOG.error("SamplerBuilder cannot find sampler class " + str +
-          ": falling back on NeverSampler.");
-      return NeverSampler.INSTANCE;
-    }
-    Constructor<Sampler> ctor = null;
-    try {
-      ctor = cls.getConstructor(HTraceConfiguration.class);
-    } catch (NoSuchMethodException e) {
-      LOG.error("SamplerBuilder cannot find a constructor for class " + str +
-          "which takes an HTraceConfiguration.  Falling back on " +
-          "NeverSampler.");
-      return NeverSampler.INSTANCE;
-    }
-    try {
-      return ctor.newInstance(conf);
-    } catch (ReflectiveOperationException e) {
-      LOG.error("SamplerBuilder reflection error when constructing " + str +
-          ".  Falling back on NeverSampler.", e);
-      return NeverSampler.INSTANCE;
-    } catch (Throwable e) {
-      LOG.error("SamplerBuilder constructor error when constructing " + str +
-          ".  Falling back on NeverSampler.", e);
-      return NeverSampler.INSTANCE;
-    }
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/Span.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/Span.java b/htrace-core/src/main/java/org/apache/htrace/Span.java
deleted file mode 100644
index 0897ee9..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/Span.java
+++ /dev/null
@@ -1,192 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import com.fasterxml.jackson.core.JsonGenerator;
-import com.fasterxml.jackson.databind.JsonSerializer;
-import com.fasterxml.jackson.databind.SerializerProvider;
-import com.fasterxml.jackson.databind.annotation.JsonSerialize;
-
-import java.io.IOException;
-import java.util.List;
-import java.util.Map;
-
-
-/**
- * Base interface for gathering and reporting statistics about a block of
- * execution.
- * <p/>
- * Spans should form a directed acyclic graph structure.  It should be possible
- * to keep following the parents of a span until you arrive at a span with no
- * parents.<p/>
- */
-@JsonSerialize(using = Span.SpanSerializer.class)
-public interface Span {
-  /**
-   * The block has completed, stop the clock
-   */
-  void stop();
-
-  /**
-   * Get the start time, in milliseconds
-   */
-  long getStartTimeMillis();
-
-  /**
-   * Get the stop time, in milliseconds
-   */
-  long getStopTimeMillis();
-
-  /**
-   * Return the total amount of time elapsed since start was called, if running,
-   * or difference between stop and start
-   */
-  long getAccumulatedMillis();
-
-  /**
-   * Has the span been started and not yet stopped?
-   */
-  boolean isRunning();
-
-  /**
-   * Return a textual description of this span.<p/>
-   *
-   * Will never be null.
-   */
-  String getDescription();
-
-  /**
-   * A pseudo-unique (random) number assigned to this span instance.<p/>
-   *
-   * The spanId is immutable and cannot be changed.  It is safe to access this
-   * from multiple threads.
-   */
-  SpanId getSpanId();
-
-  /**
-   * Create a child span of this span with the given description
-   */
-  Span child(String description);
-
-  @Override
-  String toString();
-
-  /**
-   * Returns the parent IDs of the span.<p/>
-   *
-   * The array will be empty if there are no parents.
-   */
-  SpanId[] getParents();
-
-  /**
-   * Set the parents of this span.<p/>
-   *
-   * Any existing parents will be cleared by this call.
-   */
-  void setParents(SpanId[] parents);
-
-  /**
-   * Add a data annotation associated with this span
-   */
-  void addKVAnnotation(String key, String value);
-
-  /**
-   * Add a timeline annotation associated with this span
-   */
-  void addTimelineAnnotation(String msg);
-
-  /**
-   * Get data associated with this span (read only)<p/>
-   *
-   * Will never be null.
-   */
-  Map<String, String> getKVAnnotations();
-
-  /**
-   * Get any timeline annotations (read only)<p/>
-   *
-   * Will never be null.
-   */
-  List<TimelineAnnotation> getTimelineAnnotations();
-
-  /**
-   * Return a unique id for the process from which this Span originated.<p/>
-   *
-   * Will never be null.
-   */
-  String getTracerId();
-
-  /**
-   * Set the process id of a span.
-   */
-  void setTracerId(String s);
-
-  /**
-   * Serialize to Json
-   */
-  String toJson();
-
-  public static class SpanSerializer extends JsonSerializer<Span> {
-    @Override
-    public void serialize(Span span, JsonGenerator jgen, SerializerProvider provider)
-        throws IOException {
-      jgen.writeStartObject();
-      if (span.getSpanId().isValid()) {
-        jgen.writeStringField("a", span.getSpanId().toString());
-      }
-      if (span.getStartTimeMillis() != 0) {
-        jgen.writeNumberField("b", span.getStartTimeMillis());
-      }
-      if (span.getStopTimeMillis() != 0) {
-        jgen.writeNumberField("e", span.getStopTimeMillis());
-      }
-      if (!span.getDescription().isEmpty()) {
-        jgen.writeStringField("d", span.getDescription());
-      }
-      String tracerId = span.getTracerId();
-      if (!tracerId.isEmpty()) {
-        jgen.writeStringField("r", tracerId);
-      }
-      jgen.writeArrayFieldStart("p");
-      for (SpanId parent : span.getParents()) {
-        jgen.writeString(parent.toString());
-      }
-      jgen.writeEndArray();
-      Map<String, String> traceInfoMap = span.getKVAnnotations();
-      if (!traceInfoMap.isEmpty()) {
-        jgen.writeObjectFieldStart("n");
-        for (Map.Entry<String, String> e : traceInfoMap.entrySet()) {
-          jgen.writeStringField(e.getKey(), e.getValue());
-        }
-        jgen.writeEndObject();
-      }
-      List<TimelineAnnotation> timelineAnnotations =
-          span.getTimelineAnnotations();
-      if (!timelineAnnotations.isEmpty()) {
-        jgen.writeArrayFieldStart("t");
-        for (TimelineAnnotation tl : timelineAnnotations) {
-          jgen.writeStartObject();
-          jgen.writeNumberField("t", tl.getTime());
-          jgen.writeStringField("m", tl.getMessage());
-          jgen.writeEndObject();
-        }
-        jgen.writeEndArray();
-      }
-      jgen.writeEndObject();
-    }
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/SpanId.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/SpanId.java b/htrace-core/src/main/java/org/apache/htrace/SpanId.java
deleted file mode 100644
index 25dc108..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/SpanId.java
+++ /dev/null
@@ -1,149 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import java.math.BigInteger;
-import java.lang.Void;
-import java.util.concurrent.ThreadLocalRandom;
-import java.util.Random;
-
-/**
- * Uniquely identifies an HTrace span.
- *
- * Span IDs are 128 bits in total.  The upper 64 bits of a span ID is the same
- * as the upper 64 bits of the parent span, if there is one.  The lower 64 bits
- * are always random.
- */
-public final class SpanId implements Comparable<SpanId> {
-  private static final int SPAN_ID_STRING_LENGTH = 32;
-  private final long high;
-  private final long low;
-
-  /**
-   * The invalid span ID, which is all zeroes.
-   *
-   * It is also the "least" span ID in the sense that it is considered
-   * smaller than any other span ID.
-   */
-  public static SpanId INVALID = new SpanId(0, 0);
-
-  private static long nonZeroRand64() {
-    while (true) {
-      long r = ThreadLocalRandom.current().nextLong();
-      if (r != 0) {
-        return r;
-      }
-    }
-  }
-
-  public static SpanId fromRandom() {
-    return new SpanId(nonZeroRand64(), nonZeroRand64());
-  }
-
-  public static SpanId fromString(String str) {
-    if (str.length() != SPAN_ID_STRING_LENGTH) {
-      throw new RuntimeException("Invalid SpanID string: length was not " +
-          SPAN_ID_STRING_LENGTH);
-    }
-    long high =
-      ((Long.parseLong(str.substring(0, 8), 16)) << 32) |
-      (Long.parseLong(str.substring(8, 16), 16));
-    long low =
-      ((Long.parseLong(str.substring(16, 24), 16)) << 32) |
-      (Long.parseLong(str.substring(24, 32), 16));
-    return new SpanId(high, low);
-  }
-
-  public SpanId(long high, long low) {
-    this.high = high;
-    this.low = low;
-  }
-
-  public long getHigh() {
-    return high;
-  }
-
-  public long getLow() {
-    return low;
-  }
-
-  @Override
-  public boolean equals(Object o) {
-    if (!(o instanceof SpanId)) {
-      return false;
-    }
-    SpanId other = (SpanId)o;
-    return ((other.high == high) && (other.low == low));
-  }
-
-  @Override
-  public int compareTo(SpanId other) {
-    int cmp = compareAsUnsigned(high, other.high);
-    if (cmp != 0) {
-      return cmp;
-    }
-    return compareAsUnsigned(low, other.low);
-  }
-
-  private static int compareAsUnsigned(long a, long b) {
-    boolean aSign = a < 0;
-    boolean bSign = b < 0;
-    if (aSign != bSign) {
-      if (aSign) {
-        return 1;
-      } else {
-        return -1;
-      }
-    }
-    if (aSign) {
-      a = -a;
-      b = -b;
-    }
-    if (a < b) {
-      return -1;
-    } else if (a > b) {
-      return 1;
-    } else {
-      return 0;
-    }
-  }
-
-  @Override
-  public int hashCode() {
-    return (int)((0xffffffff & (high >> 32))) ^
-           (int)((0xffffffff & (high >> 0))) ^
-           (int)((0xffffffff & (low >> 32))) ^
-           (int)((0xffffffff & (low >> 0)));
-  }
-
-  @Override
-  public String toString() {
-    return String.format("%08x%08x%08x%08x",
-        (0x00000000ffffffffL & (high >> 32)),
-        (0x00000000ffffffffL & high),
-        (0x00000000ffffffffL & (low >> 32)),
-        (0x00000000ffffffffL & low));
-  }
-
-  public boolean isValid() {
-    return (high != 0)  || (low != 0);
-  }
-
-  public SpanId newChildId() {
-    return new SpanId(high, nonZeroRand64());
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/SpanReceiver.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/SpanReceiver.java b/htrace-core/src/main/java/org/apache/htrace/SpanReceiver.java
deleted file mode 100644
index 7ae157b..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/SpanReceiver.java
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-
-import java.io.Closeable;
-
-
-/**
- * The collector within a process that is the destination of Spans when a trace is running.
- * {@code SpanReceiver} implementations are expected to provide a constructor with the signature
- * <p>
- * <pre>
- * <code>public SpanReceiverImpl(HTraceConfiguration)</code>
- * </pre>
- * The helper class {@link org.apache.htrace.SpanReceiverBuilder} provides convenient factory
- * methods for creating {@code SpanReceiver} instances from configuration.
- * @see org.apache.htrace.SpanReceiverBuilder
- */
-public interface SpanReceiver extends Closeable {
-  /**
-   * Called when a Span is stopped and can now be stored.
-   */
-  public void receiveSpan(Span span);
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/SpanReceiverBuilder.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/SpanReceiverBuilder.java b/htrace-core/src/main/java/org/apache/htrace/SpanReceiverBuilder.java
deleted file mode 100644
index 15b3af0..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/SpanReceiverBuilder.java
+++ /dev/null
@@ -1,138 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import java.lang.reflect.Constructor;
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-
-/**
- * A {@link SpanReceiver} builder. It reads a {@link SpanReceiver} class name from the provided
- * configuration using the {@link #SPAN_RECEIVER_CONF_KEY} key. Unqualified class names
- * are interpreted as members of the {@code org.apache.htrace.impl} package. The {@link #build()}
- * method constructs an instance of that class, initialized with the same configuration.
- */
-public class SpanReceiverBuilder {
-  private static final Log LOG = LogFactory.getLog(SpanReceiverBuilder.class);
-
-  public final static String SPAN_RECEIVER_CONF_KEY = "span.receiver";
-  private final static String DEFAULT_PACKAGE = "org.apache.htrace.impl";
-  private final static ClassLoader classLoader =
-      SpanReceiverBuilder.class.getClassLoader();
-  private final HTraceConfiguration conf;
-  private boolean logErrors;
-  private String spanReceiverClass;
-
-  public SpanReceiverBuilder(HTraceConfiguration conf) {
-    this.conf = conf;
-    reset();
-  }
-
-  /**
-   * Set this builder back to defaults. Any previous calls to {@link #spanReceiverClass(String)}
-   * are overridden by the value provided by configuration.
-   * @return This instance
-   */
-  public SpanReceiverBuilder reset() {
-    this.logErrors = true;
-    this.spanReceiverClass = this.conf.get(SPAN_RECEIVER_CONF_KEY);
-    return this;
-  }
-
-  /**
-   * Override the {@code SpanReceiver} class name provided in configuration with a new value.
-   * @return This instance
-   */
-  public SpanReceiverBuilder spanReceiverClass(final String spanReceiverClass) {
-    this.spanReceiverClass = spanReceiverClass;
-    return this;
-  }
-
-  /**
-   * Configure whether we should log errors during build().
-   * @return This instance
-   */
-  public SpanReceiverBuilder logErrors(boolean logErrors) {
-    this.logErrors = logErrors;
-    return this;
-  }
-
-  private void logError(String errorStr) {
-    if (!logErrors) {
-      return;
-    }
-    LOG.error(errorStr);
-  }
-
-  private void logError(String errorStr, Throwable e) {
-    if (!logErrors) {
-      return;
-    }
-    LOG.error(errorStr, e);
-  }
-
-  public SpanReceiver build() {
-    SpanReceiver spanReceiver = newSpanReceiver();
-    if (LOG.isTraceEnabled()) {
-      LOG.trace("Created new span receiver of type " +
-             ((spanReceiver == null) ? "(none)" :
-               spanReceiver.getClass().getName()));
-    }
-    return spanReceiver;
-  }
-
-  private SpanReceiver newSpanReceiver() {
-    if ((this.spanReceiverClass == null) ||
-        this.spanReceiverClass.isEmpty()) {
-      LOG.debug("No span receiver class specified.");
-      return null;
-    }
-    String str = spanReceiverClass;
-    if (!str.contains(".")) {
-      str = DEFAULT_PACKAGE + "." + str;
-    }
-    Class cls = null;
-    try {
-      cls = classLoader.loadClass(str);
-    } catch (ClassNotFoundException e) {
-      logError("SpanReceiverBuilder cannot find SpanReceiver class " + str +
-          ": disabling span receiver.");
-      return null;
-    }
-    Constructor<SpanReceiver> ctor = null;
-    try {
-      ctor = cls.getConstructor(HTraceConfiguration.class);
-    } catch (NoSuchMethodException e) {
-      logError("SpanReceiverBuilder cannot find a constructor for class " +
-          str + "which takes an HTraceConfiguration.  Disabling span " +
-          "receiver.");
-      return null;
-    }
-    try {
-      LOG.debug("Creating new instance of " + str + "...");
-      return ctor.newInstance(conf);
-    } catch (ReflectiveOperationException e) {
-      logError("SpanReceiverBuilder reflection error when constructing " + str +
-          ".  Disabling span receiver.", e);
-      return null;
-    } catch (Throwable e) {
-      logError("SpanReceiverBuilder constructor error when constructing " + str +
-          ".  Disabling span receiver.", e);
-      return null;
-    }
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/TimelineAnnotation.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/TimelineAnnotation.java b/htrace-core/src/main/java/org/apache/htrace/TimelineAnnotation.java
deleted file mode 100644
index d0ae675..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/TimelineAnnotation.java
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-public class TimelineAnnotation {
-  private final long time;
-  private final String msg;
-
-  public TimelineAnnotation(long time, String msg) {
-    this.time = time;
-    this.msg = msg;
-  }
-
-  public long getTime() {
-    return time;
-  }
-
-  public String getMessage() {
-    return msg;
-  }
-
-  @Override
-  public String toString() {
-    return "@" + time + ": " + msg;
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/Trace.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/Trace.java b/htrace-core/src/main/java/org/apache/htrace/Trace.java
deleted file mode 100644
index e782309..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/Trace.java
+++ /dev/null
@@ -1,223 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.htrace.impl.MilliSpan;
-import org.apache.htrace.impl.NeverSampler;
-import org.apache.htrace.wrappers.TraceCallable;
-import org.apache.htrace.wrappers.TraceRunnable;
-
-import java.util.concurrent.Callable;
-
-/**
- * The Trace class is the primary way to interact with the library.  It provides
- * methods to create and manipulate spans.
- *
- * A 'Span' represents a length of time.  It has many other attributes such as a
- * description, ID, and even potentially a set of key/value strings attached to
- * it.
- *
- * Each thread in your application has a single currently active currentSpan
- * associated with it.  When this is non-null, it represents the current
- * operation that the thread is doing.  Spans are NOT thread-safe, and must
- * never be used by multiple threads at once.  With care, it is possible to
- * safely pass a Span object between threads, but in most cases this is not
- * necessary.
- *
- * A 'TraceScope' can either be empty, or contain a Span.  TraceScope objects
- * implement the Java's Closeable interface.  Similar to file descriptors, they
- * must be closed after they are created.  When a TraceScope contains a Span,
- * this span is closed when the scope is closed.
- *
- * The 'startSpan' methods in this class do a few things:
- * <ul>
- *   <li>Create a new Span which has this thread's currentSpan as one of its parents.</li>
- *   <li>Set currentSpan to the new Span.</li>
- *   <li>Create a TraceSpan object to manage the new Span.</li>
- * </ul>
- *
- * Closing a TraceScope does a few things:
- * <ul>
- *   <li>It closes the span which the scope was managing.</li>
- *   <li>Set currentSpan to the previous currentSpan (which may be null).</li>
- * </ul>
- */
-public class Trace {
-  private static final Log LOG = LogFactory.getLog(Trace.class);
-
-  /**
-   * Creates a new trace scope.
-   *
-   * If this thread has a currently active trace span, the trace scope we create
-   * here will contain a new span descending from the currently active span.
-   * If there is no currently active trace span, the trace scope we create will
-   * be empty.
-   *
-   * @param description   The description field for the new span to create.
-   */
-  public static TraceScope startSpan(String description) {
-    return startSpan(description, NeverSampler.INSTANCE);
-  }
-
-  public static TraceScope startSpan(String description, SpanId parentId) {
-    if (parentId == null) {
-      return continueSpan(null);
-    }
-    Span newSpan = new MilliSpan.Builder().
-        begin(System.currentTimeMillis()).
-        end(0).
-        description(description).
-        spanId(parentId.newChildId()).
-        parents(new SpanId[] { parentId }).
-        build();
-    return continueSpan(newSpan);
-  }
-
-  /**
-   * Creates a new trace scope.
-   *
-   * If this thread has a currently active trace span, it must be the 'parent'
-   * span that you pass in here as a parameter.  The trace scope we create here
-   * will contain a new span which is a child of 'parent'.
-   *
-   * @param description   The description field for the new span to create.
-   */
-  public static TraceScope startSpan(String description, Span parent) {
-    if (parent == null) {
-      return startSpan(description);
-    }
-    Span currentSpan = currentSpan();
-    if ((currentSpan != null) && (currentSpan != parent)) {
-      Tracer.clientError("HTrace client error: thread " +
-          Thread.currentThread().getName() + " tried to start a new Span " +
-          "with parent " + parent.toString() + ", but there is already a " +
-          "currentSpan " + currentSpan);
-    }
-    return continueSpan(parent.child(description));
-  }
-
-  public static <T> TraceScope startSpan(String description, Sampler s) {
-    Span span = null;
-    if (isTracing() || s.next()) {
-      span = Tracer.getInstance().createNew(description);
-    }
-    return continueSpan(span);
-  }
-
-  /**
-   * Pick up an existing span from another thread.
-   */
-  public static TraceScope continueSpan(Span s) {
-    // Return an empty TraceScope that does nothing on close
-    if (s == null) return NullScope.INSTANCE;
-    return Tracer.getInstance().continueSpan(s);
-  }
-
-  /**
-   * Removes the given SpanReceiver from the list of SpanReceivers.
-   */
-  public static void removeReceiver(SpanReceiver rcvr) {
-    Tracer.getInstance().removeReceiver(rcvr);
-  }
-
-  /**
-   * Adds the given SpanReceiver to the current Tracer instance's list of
-   * SpanReceivers.
-   */
-  public static void addReceiver(SpanReceiver rcvr) {
-    Tracer.getInstance().addReceiver(rcvr);
-  }
-
-  /**
-   * Adds a data annotation to the current span if tracing is currently on.
-   */
-  public static void addKVAnnotation(String key, String value) {
-    Span s = currentSpan();
-    if (s != null) {
-      s.addKVAnnotation(key, value);
-    }
-  }
-
-  /**
-   * Annotate the current span with the given message.
-   */
-  public static void addTimelineAnnotation(String msg) {
-    Span s = currentSpan();
-    if (s != null) {
-      s.addTimelineAnnotation(msg);
-    }
-  }
-
-  /**
-   * Returns true if the current thread is a part of a trace, false otherwise.
-   */
-  public static boolean isTracing() {
-    return Tracer.getInstance().isTracing();
-  }
-
-  /**
-   * If we are tracing, return the current span, else null
-   *
-   * @return Span representing the current trace, or null if not tracing.
-   */
-  public static Span currentSpan() {
-    return Tracer.getInstance().currentSpan();
-  }
-
-  /**
-   * Wrap the callable in a TraceCallable, if tracing.
-   *
-   * @return The callable provided, wrapped if tracing, 'callable' if not.
-   */
-  public static <V> Callable<V> wrap(Callable<V> callable) {
-    if (isTracing()) {
-      return new TraceCallable<V>(Trace.currentSpan(), callable);
-    } else {
-      return callable;
-    }
-  }
-
-  /**
-   * Wrap the runnable in a TraceRunnable, if tracing
-   *
-   * @return The runnable provided, wrapped if tracing, 'runnable' if not.
-   */
-  public static Runnable wrap(Runnable runnable) {
-    if (isTracing()) {
-      return new TraceRunnable(Trace.currentSpan(), runnable);
-    } else {
-      return runnable;
-    }
-  }
-
-  /**
-   * Wrap the runnable in a TraceRunnable, if tracing
-   *
-   * @param description name of the span to be created.
-   * @param runnable The runnable that will have tracing info associated with it if tracing.
-   * @return The runnable provided, wrapped if tracing, 'runnable' if not.
-   */
-  public static Runnable wrap(String description, Runnable runnable) {
-    if (isTracing()) {
-      return new TraceRunnable(Trace.currentSpan(), runnable, description);
-    } else {
-      return runnable;
-    }
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/TraceScope.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/TraceScope.java b/htrace-core/src/main/java/org/apache/htrace/TraceScope.java
deleted file mode 100644
index ab36feb..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/TraceScope.java
+++ /dev/null
@@ -1,99 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import java.io.Closeable;
-import java.lang.Thread;
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-
-public class TraceScope implements Closeable {
-  private static final Log LOG = LogFactory.getLog(TraceScope.class);
-
-  /**
-   * the span for this scope
-   */
-  private final Span span;
-
-  /**
-   * the span that was "current" before this scope was entered
-   */
-  private final Span savedSpan;
-
-  private boolean detached = false;
-
-  TraceScope(Span span, Span saved) {
-    this.span = span;
-    this.savedSpan = saved;
-  }
-
-  public Span getSpan() {
-    return span;
-  }
-
-  /**
-   * Remove this span as the current thread, but don't stop it yet or
-   * send it for collection. This is useful if the span object is then
-   * passed to another thread for use with Trace.continueTrace().
-   *
-   * @return the same Span object
-   */
-  public Span detach() {
-    if (detached) {
-      Tracer.clientError("Tried to detach trace span " + span + " but " +
-          "it has already been detached.");
-    }
-    detached = true;
-
-    Span cur = Tracer.getInstance().currentSpan();
-    if (cur != span) {
-      Tracer.clientError("Tried to detach trace span " + span + " but " +
-          "it is not the current span for the " +
-          Thread.currentThread().getName() + " thread.  You have " +
-          "probably forgotten to close or detach " + cur);
-    } else {
-      Tracer.getInstance().setCurrentSpan(savedSpan);
-    }
-    return span;
-  }
-
-  /**
-   * Return true when {@link #detach()} has been called. Helpful when debugging
-   * multiple threads working on a single span.
-   */
-  public boolean isDetached() {
-    return detached;
-  }
-
-  @Override
-  public void close() {
-    if (detached) {
-      return;
-    }
-    detached = true;
-    Span cur = Tracer.getInstance().currentSpan();
-    if (cur != span) {
-      Tracer.clientError("Tried to close trace span " + span + " but " +
-          "it is not the current span for the " +
-          Thread.currentThread().getName() + " thread.  You have " +
-          "probably forgotten to close or detach " + cur);
-    } else {
-      span.stop();
-      Tracer.getInstance().setCurrentSpan(savedSpan);
-    }
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/Tracer.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/Tracer.java b/htrace-core/src/main/java/org/apache/htrace/Tracer.java
deleted file mode 100644
index d07e1a8..0000000
--- a/htrace-core/src/main/java/org/apache/htrace/Tracer.java
+++ /dev/null
@@ -1,130 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.htrace;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.htrace.impl.MilliSpan;
-
-import java.util.List;
-import java.util.Random;
-import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.concurrent.ThreadLocalRandom;
-
-/**
- * A Tracer provides the implementation for collecting and distributing Spans
- * within a process.
- */
-public class Tracer {
-  private static final Log LOG = LogFactory.getLog(Tracer.class);
-
-  static long nonZeroRandom64() {
-    long id;
-    Random random = ThreadLocalRandom.current();
-    do {
-      id = random.nextLong();
-    } while (id == 0);
-    return id;
-  }
-
-  private final List<SpanReceiver> receivers = new CopyOnWriteArrayList<SpanReceiver>();
-  private static final ThreadLocal<Span> currentSpan = new ThreadLocal<Span>() {
-    @Override
-    protected Span initialValue() {
-      return null;
-    }
-  };
-  private static final SpanId EMPTY_PARENT_ARRAY[] = new SpanId[0];
-
-  /**
-   * Log a client error, and throw an exception.
-   *
-   * @param str     The message to use in the log and the exception.
-   */
-  static void clientError(String str) {
-    LOG.error(str);
-    throw new RuntimeException(str);
-  }
-
-  /**
-   * Internal class for defered singleton idiom.
-   * <p/>
-   * https://en.wikipedia.org/wiki/Initialization_on_demand_holder_idiom
-   */
-  private static class TracerHolder {
-    private static final Tracer INSTANCE = new Tracer();
-  }
-
-  public static Tracer getInstance() {
-    return TracerHolder.INSTANCE;
-  }
-
-  protected Span createNew(String description) {
-    Span parent = currentSpan.get();
-    if (parent == null) {
-      return new MilliSpan.Builder().
-          begin(System.currentTimeMillis()).
-          end(0).
-          description(description).
-          parents(EMPTY_PARENT_ARRAY).
-          spanId(SpanId.fromRandom()).
-          build();
-    } else {
-      return parent.child(description);
-    }
-  }
-
-  protected boolean isTracing() {
-    return currentSpan.get() != null;
-  }
-
-  protected Span currentSpan() {
-    return currentSpan.get();
-  }
-
-  public void deliver(Span span) {
-    for (SpanReceiver receiver : receivers) {
-      receiver.receiveSpan(span);
-    }
-  }
-
-  protected void addReceiver(SpanReceiver receiver) {
-    receivers.add(receiver);
-  }
-
-  protected void removeReceiver(SpanReceiver receiver) {
-    receivers.remove(receiver);
-  }
-
-  protected Span setCurrentSpan(Span span) {
-    if (LOG.isTraceEnabled()) {
-      LOG.trace("setting current span " + span);
-    }
-    currentSpan.set(span);
-    return span;
-  }
-
-  public TraceScope continueSpan(Span s) {
-    Span oldCurrent = currentSpan();
-    setCurrentSpan(s);
-    return new TraceScope(s, oldCurrent);
-  }
-
-  protected int numReceivers() {
-    return receivers.size();
-  }
-}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/AlwaysSampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/AlwaysSampler.java b/htrace-core/src/main/java/org/apache/htrace/core/AlwaysSampler.java
new file mode 100644
index 0000000..a9259bd
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/AlwaysSampler.java
@@ -0,0 +1,33 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+/**
+ * A Sampler that always returns true.
+ */
+public final class AlwaysSampler implements Sampler {
+
+  public static final AlwaysSampler INSTANCE = new AlwaysSampler(null);
+
+  public AlwaysSampler(HTraceConfiguration conf) {
+  }
+
+  @Override
+  public boolean next() {
+    return true;
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/CountSampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/CountSampler.java b/htrace-core/src/main/java/org/apache/htrace/core/CountSampler.java
new file mode 100644
index 0000000..10d5c98
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/CountSampler.java
@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * Sampler that returns true every N calls. Specify the frequency interval by configuring a
+ * {@code long} value for {@link #SAMPLER_FREQUENCY_CONF_KEY}.
+ */
+public class CountSampler implements Sampler {
+  public final static String SAMPLER_FREQUENCY_CONF_KEY = "sampler.frequency";
+
+  final long frequency;
+  long count = ThreadLocalRandom.current().nextLong();
+
+  public CountSampler(HTraceConfiguration conf) {
+    this.frequency = Long.parseLong(conf.get(SAMPLER_FREQUENCY_CONF_KEY), 10);
+  }
+
+  @Override
+  public boolean next() {
+    return (count++ % frequency) == 0;
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/HTraceConfiguration.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/HTraceConfiguration.java b/htrace-core/src/main/java/org/apache/htrace/core/HTraceConfiguration.java
new file mode 100644
index 0000000..c6e445b
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/HTraceConfiguration.java
@@ -0,0 +1,109 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Wrapper which integrating applications should implement in order
+ * to provide tracing configuration.
+ */
+public abstract class HTraceConfiguration {
+
+  private static final Log LOG = LogFactory.getLog(HTraceConfiguration.class);
+
+  private static final Map<String, String> EMPTY_MAP = new HashMap<String, String>(1);
+
+  /**
+   * An empty HTrace configuration.
+   */
+  public static final HTraceConfiguration EMPTY = fromMap(EMPTY_MAP);
+
+  /**
+   * Create an HTrace configuration from a map.
+   *
+   * @param conf    The map to create the configuration from.
+   * @return        The new configuration.
+   */
+  public static HTraceConfiguration fromMap(Map<String, String> conf) {
+    return new MapConf(conf);
+  }
+
+  public static HTraceConfiguration fromKeyValuePairs(String... pairs) {
+    if ((pairs.length % 2) != 0) {
+      throw new RuntimeException("You must specify an equal number of keys " +
+          "and values.");
+    }
+    Map<String, String> conf = new HashMap<String, String>();
+    for (int i = 0; i < pairs.length; i+=2) {
+      conf.put(pairs[i], pairs[i + 1]);
+    }
+    return new MapConf(conf);
+  }
+
+  public abstract String get(String key);
+
+  public abstract String get(String key, String defaultValue);
+
+  public boolean getBoolean(String key, boolean defaultValue) {
+    String value = get(key, String.valueOf(defaultValue)).trim().toLowerCase();
+
+    if ("true".equals(value)) {
+      return true;
+    } else if ("false".equals(value)) {
+      return false;
+    }
+
+    LOG.warn("Expected boolean for key [" + key + "] instead got [" + value + "].");
+    return defaultValue;
+  }
+
+  public int getInt(String key, int defaultVal) {
+    String val = get(key);
+    if (val == null || val.trim().isEmpty()) {
+      return defaultVal;
+    }
+    try {
+      return Integer.parseInt(val);
+    } catch (NumberFormatException nfe) {
+      throw new IllegalArgumentException("Bad value for '" + key + "': should be int");
+    }
+  }
+
+  private static class MapConf extends HTraceConfiguration {
+    private final Map<String, String> conf;
+
+    public MapConf(Map<String, String> conf) {
+      this.conf = new HashMap<String, String>(conf);
+    }
+
+    @Override
+    public String get(String key) {
+      return conf.get(key);
+    }
+
+    @Override
+    public String get(String key, String defaultValue) {
+      String value = get(key);
+      return value == null ? defaultValue : value;
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/LocalFileSpanReceiver.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/LocalFileSpanReceiver.java b/htrace-core/src/main/java/org/apache/htrace/core/LocalFileSpanReceiver.java
new file mode 100644
index 0000000..0aed846
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/LocalFileSpanReceiver.java
@@ -0,0 +1,261 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.EOFException;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.file.FileSystems;
+import java.nio.file.StandardOpenOption;
+import java.util.UUID;
+import java.util.concurrent.locks.ReentrantLock;
+
+/**
+ * Writes the spans it receives to a local file.
+ */
+public class LocalFileSpanReceiver implements SpanReceiver {
+  private static final Log LOG = LogFactory.getLog(LocalFileSpanReceiver.class);
+  public static final String PATH_KEY = "local-file-span-receiver.path";
+  public static final String CAPACITY_KEY = "local-file-span-receiver.capacity";
+  public static final int CAPACITY_DEFAULT = 5000;
+  private static ObjectWriter JSON_WRITER = new ObjectMapper().writer();
+  private final String path;
+
+  private byte[][] bufferedSpans;
+  private int bufferedSpansIndex;
+  private final ReentrantLock bufferLock = new ReentrantLock();
+
+  private final FileOutputStream stream;
+  private final FileChannel channel;
+  private final ReentrantLock channelLock = new ReentrantLock();
+  private final TracerId tracerId;
+
+  public LocalFileSpanReceiver(HTraceConfiguration conf) {
+    int capacity = conf.getInt(CAPACITY_KEY, CAPACITY_DEFAULT);
+    if (capacity < 1) {
+      throw new IllegalArgumentException(CAPACITY_KEY + " must not be " +
+          "less than 1.");
+    }
+    this.path = conf.get(PATH_KEY);
+    if (path == null || path.isEmpty()) {
+      throw new IllegalArgumentException("must configure " + PATH_KEY);
+    }
+    boolean success = false;
+    try {
+      this.stream = new FileOutputStream(path, true);
+    } catch (IOException ioe) {
+      LOG.error("Error opening " + path + ": " + ioe.getMessage());
+      throw new RuntimeException(ioe);
+    }
+    this.channel = stream.getChannel();
+    if (this.channel == null) {
+      try {
+        this.stream.close();
+      } catch (IOException e) {
+        LOG.error("Error closing " + path, e);
+      }
+      LOG.error("Failed to get channel for " + path);
+      throw new RuntimeException("Failed to get channel for " + path);
+    }
+    this.bufferedSpans = new byte[capacity][];
+    this.bufferedSpansIndex = 0;
+    if (LOG.isDebugEnabled()) {
+      LOG.debug("Created new LocalFileSpanReceiver with path = " + path +
+                ", capacity = " + capacity);
+    }
+    this.tracerId = new TracerId(conf);
+  }
+
+  /**
+   * Number of buffers to use in FileChannel#write.
+   *
+   * On UNIX, FileChannel#write uses writev-- a kernel interface that allows
+   * us to send multiple buffers at once.  This is more efficient than making a
+   * separate write call for each buffer, since it minimizes the number of
+   * transitions from userspace to kernel space.
+   */
+  private final int WRITEV_SIZE = 20;
+
+  private final static ByteBuffer newlineBuf = 
+      ByteBuffer.wrap(new byte[] { (byte)0xa });
+
+  /**
+   * Flushes a bufferedSpans array.
+   */
+  private void doFlush(byte[][] toFlush, int len) throws IOException {
+    int bidx = 0, widx = 0;
+    ByteBuffer writevBufs[] = new ByteBuffer[2 * WRITEV_SIZE];
+
+    while (true) {
+      if (widx == writevBufs.length) {
+        channel.write(writevBufs);
+        widx = 0;
+      }
+      if (bidx == len) {
+        break;
+      }
+      writevBufs[widx] = ByteBuffer.wrap(toFlush[bidx]);
+      writevBufs[widx + 1] = newlineBuf;
+      bidx++;
+      widx+=2;
+    }
+    if (widx > 0) {
+      channel.write(writevBufs, 0, widx);
+    }
+  }
+
+  @Override
+  public void receiveSpan(Span span) {
+    if (span.getTracerId().isEmpty()) {
+      span.setTracerId(tracerId.get());
+    }
+
+    // Serialize the span data into a byte[].  Note that we're not holding the
+    // lock here, to improve concurrency.
+    byte jsonBuf[] = null;
+    try {
+      jsonBuf = JSON_WRITER.writeValueAsBytes(span);
+    } catch (JsonProcessingException e) {
+        LOG.error("receiveSpan(path=" + path + ", span=" + span + "): " +
+                  "Json processing error: " + e.getMessage());
+      return;
+    }
+
+    // Grab the bufferLock and put our jsonBuf into the list of buffers to
+    // flush. 
+    byte toFlush[][] = null;
+    bufferLock.lock();
+    try {
+      if (bufferedSpans == null) {
+        LOG.debug("receiveSpan(path=" + path + ", span=" + span + "): " +
+                  "LocalFileSpanReceiver for " + path + " is closed.");
+        return;
+      }
+      bufferedSpans[bufferedSpansIndex] = jsonBuf;
+      bufferedSpansIndex++;
+      if (bufferedSpansIndex == bufferedSpans.length) {
+        // If we've hit the limit for the number of buffers to flush, 
+        // swap out the existing bufferedSpans array for a new array, and
+        // prepare to flush those spans to disk.
+        toFlush = bufferedSpans;
+        bufferedSpansIndex = 0;
+        bufferedSpans = new byte[bufferedSpans.length][];
+      }
+    } finally {
+      bufferLock.unlock();
+    }
+    if (toFlush != null) {
+      // We released the bufferLock above, to avoid blocking concurrent
+      // receiveSpan calls.  But now, we must take the channelLock, to make
+      // sure that we have sole access to the output channel.  If we did not do
+      // this, we might get interleaved output.
+      //
+      // There is a small chance that another thread doing a flush of more
+      // recent spans could get ahead of us here, and take the lock before we
+      // do.  This is ok, since spans don't have to be written out in order.
+      channelLock.lock();
+      try {
+        doFlush(toFlush, toFlush.length);
+      } catch (IOException ioe) {
+        LOG.error("Error flushing buffers to " + path + ": " +
+            ioe.getMessage());
+      } finally {
+        channelLock.unlock();
+      }
+    }
+  }
+
+  @Override
+  public void close() throws IOException {
+    byte toFlush[][] = null;
+    int numToFlush = 0;
+    bufferLock.lock();
+    try {
+      if (bufferedSpans == null) {
+        LOG.info("LocalFileSpanReceiver for " + path + " was already closed.");
+        return;
+      }
+      numToFlush = bufferedSpansIndex;
+      bufferedSpansIndex = 0;
+      toFlush = bufferedSpans;
+      bufferedSpans = null;
+    } finally {
+      bufferLock.unlock();
+    }
+    channelLock.lock();
+    try {
+      doFlush(toFlush, numToFlush);
+    } catch (IOException ioe) {
+      LOG.error("Error flushing buffers to " + path + ": " +
+          ioe.getMessage());
+    } finally {
+      try {
+        stream.close();
+      } catch (IOException e) {
+        LOG.error("Error closing stream for " + path, e);
+      }
+      channelLock.unlock();
+    }
+  }
+
+  public static String getUniqueLocalTraceFileName() {
+    String tmp = System.getProperty("java.io.tmpdir", "/tmp");
+    String nonce = null;
+    BufferedReader reader = null;
+    try {
+      // On Linux we can get a unique local file name by reading the process id
+      // out of /proc/self/stat.  (There isn't any portable way to get the
+      // process ID from Java.)
+      reader = new BufferedReader(
+          new InputStreamReader(new FileInputStream("/proc/self/stat"),
+                                "UTF-8"));
+      String line = reader.readLine();
+      if (line == null) {
+        throw new EOFException();
+      }
+      nonce = line.split(" ")[0];
+    } catch (IOException e) {
+    } finally {
+      if (reader != null) {
+        try {
+          reader.close();
+        } catch(IOException e) {
+          LOG.warn("Exception in closing " + reader, e);
+        }
+      }
+    }
+    if (nonce == null) {
+      // If we can't use the process ID, use a random nonce.
+      nonce = UUID.randomUUID().toString();
+    }
+    return new File(tmp, nonce).getAbsolutePath();
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/MilliSpan.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/MilliSpan.java b/htrace-core/src/main/java/org/apache/htrace/core/MilliSpan.java
new file mode 100644
index 0000000..49b5fbe
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/MilliSpan.java
@@ -0,0 +1,348 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.UnsupportedEncodingException;
+import java.math.BigInteger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * A Span implementation that stores its information in milliseconds since the
+ * epoch.
+ */
+@JsonDeserialize(using = MilliSpan.MilliSpanDeserializer.class)
+public class MilliSpan implements Span {
+  private static ObjectMapper OBJECT_MAPPER = new ObjectMapper();
+  private static ObjectReader JSON_READER = OBJECT_MAPPER.reader(MilliSpan.class);
+  private static ObjectWriter JSON_WRITER = OBJECT_MAPPER.writer();
+  private static final SpanId EMPTY_PARENT_ARRAY[] = new SpanId[0];
+  private static final String EMPTY_STRING = "";
+
+  private long begin;
+  private long end;
+  private final String description;
+  private SpanId parents[];
+  private final SpanId spanId;
+  private Map<String, String> traceInfo = null;
+  private String tracerId;
+  private List<TimelineAnnotation> timeline = null;
+
+  @Override
+  public Span child(String childDescription) {
+    return new MilliSpan.Builder().
+      begin(System.currentTimeMillis()).
+      end(0).
+      description(childDescription).
+      parents(new SpanId[] {spanId}).
+      spanId(spanId.newChildId()).
+      tracerId(tracerId).
+      build();
+  }
+
+  /**
+   * The public interface for constructing a MilliSpan.
+   */
+  public static class Builder {
+    private long begin;
+    private long end;
+    private String description = EMPTY_STRING;
+    private SpanId parents[] = EMPTY_PARENT_ARRAY;
+    private SpanId spanId = SpanId.INVALID;
+    private Map<String, String> traceInfo = null;
+    private String tracerId = EMPTY_STRING;
+    private List<TimelineAnnotation> timeline = null;
+
+    public Builder() {
+    }
+
+    public Builder begin(long begin) {
+      this.begin = begin;
+      return this;
+    }
+
+    public Builder end(long end) {
+      this.end = end;
+      return this;
+    }
+
+    public Builder description(String description) {
+      this.description = description;
+      return this;
+    }
+
+    public Builder parents(SpanId parents[]) {
+      this.parents = parents;
+      return this;
+    }
+
+    public Builder parents(List<SpanId> parentList) {
+      SpanId[] parents = new SpanId[parentList.size()];
+      for (int i = 0; i < parentList.size(); i++) {
+        parents[i] = parentList.get(i);
+      }
+      this.parents = parents;
+      return this;
+    }
+
+    public Builder spanId(SpanId spanId) {
+      this.spanId = spanId;
+      return this;
+    }
+
+    public Builder traceInfo(Map<String, String> traceInfo) {
+      this.traceInfo = traceInfo.isEmpty() ? null : traceInfo;
+      return this;
+    }
+
+    public Builder tracerId(String tracerId) {
+      this.tracerId = tracerId;
+      return this;
+    }
+
+    public Builder timeline(List<TimelineAnnotation> timeline) {
+      this.timeline = timeline.isEmpty() ? null : timeline;
+      return this;
+    }
+
+    public MilliSpan build() {
+      return new MilliSpan(this);
+    }
+  }
+
+  public MilliSpan() {
+    this.begin = 0;
+    this.end = 0;
+    this.description = EMPTY_STRING;
+    this.parents = EMPTY_PARENT_ARRAY;
+    this.spanId = SpanId.INVALID;
+    this.traceInfo = null;
+    this.tracerId = EMPTY_STRING;
+    this.timeline = null;
+  }
+
+  private MilliSpan(Builder builder) {
+    this.begin = builder.begin;
+    this.end = builder.end;
+    this.description = builder.description;
+    this.parents = builder.parents;
+    this.spanId = builder.spanId;
+    this.traceInfo = builder.traceInfo;
+    this.tracerId = builder.tracerId;
+    this.timeline = builder.timeline;
+  }
+
+  @Override
+  public synchronized void stop() {
+    if (end == 0) {
+      if (begin == 0)
+        throw new IllegalStateException("Span for " + description
+            + " has not been started");
+      end = System.currentTimeMillis();
+      Tracer.getInstance().deliver(this);
+    }
+  }
+
+  protected long currentTimeMillis() {
+    return System.currentTimeMillis();
+  }
+
+  @Override
+  public synchronized boolean isRunning() {
+    return begin != 0 && end == 0;
+  }
+
+  @Override
+  public synchronized long getAccumulatedMillis() {
+    if (begin == 0)
+      return 0;
+    if (end > 0)
+      return end - begin;
+    return currentTimeMillis() - begin;
+  }
+
+  @Override
+  public String toString() {
+    return toJson();
+  }
+
+  @Override
+  public String getDescription() {
+    return description;
+  }
+
+  @Override
+  public SpanId getSpanId() {
+    return spanId;
+  }
+
+  @Override
+  public SpanId[] getParents() {
+    return parents;
+  }
+
+  @Override
+  public void setParents(SpanId[] parents) {
+    this.parents = parents;
+  }
+
+  @Override
+  public long getStartTimeMillis() {
+    return begin;
+  }
+
+  @Override
+  public long getStopTimeMillis() {
+    return end;
+  }
+
+  @Override
+  public void addKVAnnotation(String key, String value) {
+    if (traceInfo == null)
+      traceInfo = new HashMap<String, String>();
+    traceInfo.put(key, value);
+  }
+
+  @Override
+  public void addTimelineAnnotation(String msg) {
+    if (timeline == null) {
+      timeline = new ArrayList<TimelineAnnotation>();
+    }
+    timeline.add(new TimelineAnnotation(System.currentTimeMillis(), msg));
+  }
+
+  @Override
+  public Map<String, String> getKVAnnotations() {
+    if (traceInfo == null)
+      return Collections.emptyMap();
+    return Collections.unmodifiableMap(traceInfo);
+  }
+
+  @Override
+  public List<TimelineAnnotation> getTimelineAnnotations() {
+    if (timeline == null) {
+      return Collections.emptyList();
+    }
+    return Collections.unmodifiableList(timeline);
+  }
+
+  @Override
+  public String getTracerId() {
+    return tracerId;
+  }
+
+  @Override
+  public void setTracerId(String tracerId) {
+    this.tracerId = tracerId;
+  }
+
+  @Override
+  public String toJson() {
+    StringWriter writer = new StringWriter();
+    try {
+      JSON_WRITER.writeValue(writer, this);
+    } catch (IOException e) {
+      // An IOException should not be possible when writing to a string.
+      throw new RuntimeException(e);
+    }
+    return writer.toString();
+  }
+
+  public static class MilliSpanDeserializer
+        extends JsonDeserializer<MilliSpan> {
+    @Override
+    public MilliSpan deserialize(JsonParser jp, DeserializationContext ctxt)
+          throws IOException, JsonProcessingException {
+      JsonNode root = jp.getCodec().readTree(jp);
+      Builder builder = new Builder();
+      JsonNode bNode = root.get("b");
+      if (bNode != null) {
+        builder.begin(bNode.asLong());
+      }
+      JsonNode eNode = root.get("e");
+      if (eNode != null) {
+        builder.end(eNode.asLong());
+      }
+      JsonNode dNode = root.get("d");
+      if (dNode != null) {
+        builder.description(dNode.asText());
+      }
+      JsonNode sNode = root.get("a");
+      if (sNode != null) {
+        builder.spanId(SpanId.fromString(sNode.asText()));
+      }
+      JsonNode rNode = root.get("r");
+      if (rNode != null) {
+        builder.tracerId(rNode.asText());
+      }
+      JsonNode parentsNode = root.get("p");
+      LinkedList<SpanId> parents = new LinkedList<SpanId>();
+      if (parentsNode != null) {
+        for (Iterator<JsonNode> iter = parentsNode.elements();
+             iter.hasNext(); ) {
+          JsonNode parentIdNode = iter.next();
+          parents.add(SpanId.fromString(parentIdNode.asText()));
+        }
+      }
+      builder.parents(parents);
+      JsonNode traceInfoNode = root.get("n");
+      if (traceInfoNode != null) {
+        HashMap<String, String> traceInfo = new HashMap<String, String>();
+        for (Iterator<String> iter = traceInfoNode.fieldNames();
+             iter.hasNext(); ) {
+          String field = iter.next();
+          traceInfo.put(field, traceInfoNode.get(field).asText());
+        }
+        builder.traceInfo(traceInfo);
+      }
+      JsonNode timelineNode = root.get("t");
+      if (timelineNode != null) {
+        LinkedList<TimelineAnnotation> timeline =
+            new LinkedList<TimelineAnnotation>();
+        for (Iterator<JsonNode> iter = timelineNode.elements();
+             iter.hasNext(); ) {
+          JsonNode ann = iter.next();
+          timeline.add(new TimelineAnnotation(ann.get("t").asLong(),
+              ann.get("m").asText()));
+        }
+        builder.timeline(timeline);
+      }
+      return builder.build();
+    }
+  }
+
+  static MilliSpan fromJson(String json) throws IOException {
+    return JSON_READER.readValue(json);
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/NeverSampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/NeverSampler.java b/htrace-core/src/main/java/org/apache/htrace/core/NeverSampler.java
new file mode 100644
index 0000000..65f6087
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/NeverSampler.java
@@ -0,0 +1,34 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+/**
+ * A Sampler that never returns true.
+ */
+public final class NeverSampler implements Sampler {
+
+  public static final NeverSampler INSTANCE = new NeverSampler(null);
+
+  public NeverSampler(HTraceConfiguration conf) {
+  }
+
+  @Override
+  public boolean next() {
+    return false;
+  }
+
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/NullScope.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/NullScope.java b/htrace-core/src/main/java/org/apache/htrace/core/NullScope.java
new file mode 100644
index 0000000..e7964cf
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/NullScope.java
@@ -0,0 +1,44 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+/**
+ * Singleton instance representing an empty {@link TraceScope}.
+ */
+public final class NullScope extends TraceScope {
+
+  public static final TraceScope INSTANCE = new NullScope();
+
+  private NullScope() {
+    super(null, null);
+  }
+
+  @Override
+  public Span detach() {
+    return null;
+  }
+
+  @Override
+  public void close() {
+    return;
+  }
+
+  @Override
+  public String toString() {
+    return "NullScope";
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/POJOSpanReceiver.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/POJOSpanReceiver.java b/htrace-core/src/main/java/org/apache/htrace/core/POJOSpanReceiver.java
new file mode 100644
index 0000000..be782ba
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/POJOSpanReceiver.java
@@ -0,0 +1,49 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.HashSet;
+
+/**
+ * SpanReceiver for testing only that just collects the Span objects it
+ * receives. The spans it receives can be accessed with getSpans();
+ */
+public class POJOSpanReceiver implements SpanReceiver {
+  private final Collection<Span> spans;
+
+  public POJOSpanReceiver(HTraceConfiguration conf) {
+    this.spans = new HashSet<Span>();
+  }
+
+  /**
+   * @return The spans this POJOSpanReceiver has received.
+   */
+  public Collection<Span> getSpans() {
+    return spans;
+  }
+
+  @Override
+  public void close() throws IOException {
+  }
+
+  @Override
+  public void receiveSpan(Span span) {
+    spans.add(span);
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-htrace/blob/fd889b65/htrace-core/src/main/java/org/apache/htrace/core/ProbabilitySampler.java
----------------------------------------------------------------------
diff --git a/htrace-core/src/main/java/org/apache/htrace/core/ProbabilitySampler.java b/htrace-core/src/main/java/org/apache/htrace/core/ProbabilitySampler.java
new file mode 100644
index 0000000..5bb0042
--- /dev/null
+++ b/htrace-core/src/main/java/org/apache/htrace/core/ProbabilitySampler.java
@@ -0,0 +1,46 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.htrace.core;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import java.util.Random;
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * Sampler that returns true a certain percentage of the time. Specify the frequency interval by
+ * configuring a {@code double} value for {@link #SAMPLER_FRACTION_CONF_KEY}.
+ */
+public class ProbabilitySampler implements Sampler {
+  private static final Log LOG = LogFactory.getLog(ProbabilitySampler.class);
+  public final double threshold;
+  public final static String SAMPLER_FRACTION_CONF_KEY = "sampler.fraction";
+
+  public ProbabilitySampler(HTraceConfiguration conf) {
+    this.threshold = Double.parseDouble(conf.get(SAMPLER_FRACTION_CONF_KEY));
+    if (LOG.isTraceEnabled()) {
+      LOG.trace("Created new ProbabilitySampler with threshold = " +
+                threshold + ".");
+    }
+  }
+
+  @Override
+  public boolean next() {
+    return ThreadLocalRandom.current().nextDouble() < threshold;
+  }
+}