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Posted to commits@camel.apache.org by da...@apache.org on 2016/04/19 08:50:19 UTC

[2/3] camel git commit: CAMEL-9879: Circuit Breaker EIP - That is using hystrix

CAMEL-9879: Circuit Breaker EIP - That is using hystrix


Project: http://git-wip-us.apache.org/repos/asf/camel/repo
Commit: http://git-wip-us.apache.org/repos/asf/camel/commit/39663b27
Tree: http://git-wip-us.apache.org/repos/asf/camel/tree/39663b27
Diff: http://git-wip-us.apache.org/repos/asf/camel/diff/39663b27

Branch: refs/heads/hys
Commit: 39663b279eb48d64155bea3654f5ca53f027171b
Parents: 22d8371
Author: Claus Ibsen <da...@apache.org>
Authored: Tue Apr 19 08:42:07 2016 +0200
Committer: Claus Ibsen <da...@apache.org>
Committed: Tue Apr 19 08:42:07 2016 +0200

----------------------------------------------------------------------
 .../component/hystrix/HystrixProcessor.java     | 37 +++++++++++---
 .../hystrix/HystrixProcessorCommand.java        | 50 ++++++++++++------
 .../hystrix/HystrixRouteFallbackTest.java       |  2 +-
 .../camel/component/hystrix/TryCatchTest.java   | 53 ++++++++++++++++++++
 .../src/test/resources/log4j.properties         |  2 +-
 5 files changed, 121 insertions(+), 23 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/camel/blob/39663b27/components/camel-hystrix/src/main/java/org/apache/camel/component/hystrix/HystrixProcessor.java
----------------------------------------------------------------------
diff --git a/components/camel-hystrix/src/main/java/org/apache/camel/component/hystrix/HystrixProcessor.java b/components/camel-hystrix/src/main/java/org/apache/camel/component/hystrix/HystrixProcessor.java
index 81b09e4..495706f 100644
--- a/components/camel-hystrix/src/main/java/org/apache/camel/component/hystrix/HystrixProcessor.java
+++ b/components/camel-hystrix/src/main/java/org/apache/camel/component/hystrix/HystrixProcessor.java
@@ -88,18 +88,22 @@ public class HystrixProcessor extends ServiceSupport implements AsyncProcessor,
         // run this as if we run inside try .. catch so there is no regular Camel error handler
         exchange.setProperty(Exchange.TRY_ROUTE_BLOCK, true);
 
+        // use our callback that does some cleanup when done
+        AsyncCallback hystrixCallback = new HystrixAsyncCallback(exchange, callback);
+
         HystrixCommandGroupKey key = HystrixCommandGroupKey.Factory.asKey(id);
-        HystrixProcessorCommand command = new HystrixProcessorCommand(key, exchange, callback, processor, fallback);
+        HystrixProcessorCommand command = new HystrixProcessorCommand(key, exchange, hystrixCallback, processor, fallback);
         try {
-            command.execute();
+            command.queue();
         } catch (Throwable e) {
+            // error adding to queue, so set as error and we are done
             exchange.setException(e);
+            exchange.removeProperty(Exchange.TRY_ROUTE_BLOCK);
+            callback.done(true);
+            return true;
         }
 
-        exchange.removeProperty(Exchange.TRY_ROUTE_BLOCK);
-
-        callback.done(true);
-        return true;
+        return false;
     }
 
     @Override
@@ -111,4 +115,25 @@ public class HystrixProcessor extends ServiceSupport implements AsyncProcessor,
     protected void doStop() throws Exception {
         // noop
     }
+
+    private static final class HystrixAsyncCallback implements AsyncCallback {
+
+        private final Exchange exchange;
+        private final AsyncCallback delegate;
+
+        public HystrixAsyncCallback(Exchange exchange, AsyncCallback delegate) {
+            this.exchange = exchange;
+            this.delegate = delegate;
+        }
+
+        @Override
+        public void done(boolean doneSync) {
+            if (doneSync) {
+                return;
+            }
+            // we are only done when called with false
+            exchange.removeProperty(Exchange.TRY_ROUTE_BLOCK);
+            delegate.done(doneSync);
+        }
+    }
 }

http://git-wip-us.apache.org/repos/asf/camel/blob/39663b27/components/camel-hystrix/src/main/java/org/apache/camel/component/hystrix/HystrixProcessorCommand.java
----------------------------------------------------------------------
diff --git a/components/camel-hystrix/src/main/java/org/apache/camel/component/hystrix/HystrixProcessorCommand.java b/components/camel-hystrix/src/main/java/org/apache/camel/component/hystrix/HystrixProcessorCommand.java
index 66a8150..299819e 100644
--- a/components/camel-hystrix/src/main/java/org/apache/camel/component/hystrix/HystrixProcessorCommand.java
+++ b/components/camel-hystrix/src/main/java/org/apache/camel/component/hystrix/HystrixProcessorCommand.java
@@ -21,12 +21,15 @@ import com.netflix.hystrix.HystrixCommandGroupKey;
 import org.apache.camel.AsyncCallback;
 import org.apache.camel.AsyncProcessor;
 import org.apache.camel.Exchange;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Hystrix Command for the Camel Hystrix EIP.
  */
 public class HystrixProcessorCommand extends HystrixCommand<Exchange> {
 
+    private static final Logger LOG = LoggerFactory.getLogger(HystrixProcessorCommand.class);
     private final Exchange exchange;
     private final AsyncCallback callback;
     private final AsyncProcessor processor;
@@ -43,46 +46,63 @@ public class HystrixProcessorCommand extends HystrixCommand<Exchange> {
 
     @Override
     protected Exchange getFallback() {
-        if (fallback != null) {
-            try {
-                Exception e = exchange.getException();
+        // only run fallback if there was an exception
+        Exception exception = exchange.getException();
+        if (exception == null) {
+            return exchange;
+        }
+
+        try {
+            if (fallback != null) {
                 // store the last to endpoint as the failure endpoint
                 if (exchange.getProperty(Exchange.FAILURE_ENDPOINT) == null) {
                     exchange.setProperty(Exchange.FAILURE_ENDPOINT, exchange.getProperty(Exchange.TO_ENDPOINT));
                 }
                 // give the rest of the pipeline another chance
                 exchange.setProperty(Exchange.EXCEPTION_HANDLED, true);
-                exchange.setProperty(Exchange.EXCEPTION_CAUGHT, e);
+                exchange.setProperty(Exchange.EXCEPTION_CAUGHT, exception);
                 exchange.setException(null);
                 // and we should not be regarded as exhausted as we are in a try .. catch block
                 exchange.removeProperty(Exchange.REDELIVERY_EXHAUSTED);
-
-                fallback.process(exchange, callback);
-            } catch (Exception e) {
-                exchange.setException(e);
-            } finally {
-                callback.done(true);
+                // run the fallback processor
+                try {
+                    LOG.debug("Running fallback: {}", exchange);
+                    fallback.process(exchange, callback);
+                } catch (Exception e) {
+                    exchange.setException(e);
+                }
             }
-            return exchange;
-        } else {
-            return null;
+        } finally {
+            LOG.debug("Running fallback: {} success", exchange);
+            callback.done(false);
         }
+
+        return exchange;
     }
 
     @Override
     protected Exchange run() throws Exception {
+        LOG.debug("Running processor: {}", exchange);
+
+        exchange.setProperty(Exchange.EXCEPTION_HANDLED, null);
+        exchange.setProperty(Exchange.TRY_ROUTE_BLOCK, true);
         try {
             processor.process(exchange, callback);
         } catch (Exception e) {
             exchange.setException(e);
-        } finally {
-            callback.done(true);
         }
 
         // if we failed then throw an exception
         if (exchange.getException() != null) {
             throw exchange.getException();
         }
+        // no errors we are done
+        try {
+            LOG.debug("Running processor: {} success", exchange);
+            callback.done(false);
+        } catch (Throwable e) {
+            exchange.setException(e);
+        }
 
         return exchange;
     }

http://git-wip-us.apache.org/repos/asf/camel/blob/39663b27/components/camel-hystrix/src/test/java/org/apache/camel/component/hystrix/HystrixRouteFallbackTest.java
----------------------------------------------------------------------
diff --git a/components/camel-hystrix/src/test/java/org/apache/camel/component/hystrix/HystrixRouteFallbackTest.java b/components/camel-hystrix/src/test/java/org/apache/camel/component/hystrix/HystrixRouteFallbackTest.java
index 43aa817..dc7c766 100644
--- a/components/camel-hystrix/src/test/java/org/apache/camel/component/hystrix/HystrixRouteFallbackTest.java
+++ b/components/camel-hystrix/src/test/java/org/apache/camel/component/hystrix/HystrixRouteFallbackTest.java
@@ -44,7 +44,7 @@ public class HystrixRouteFallbackTest extends CamelTestSupport {
                     .end()
                     .to("mock:result");
 
-                from("direct:foo")
+                from("direct:foo").errorHandler(noErrorHandler())
                     .throwException(new IllegalArgumentException("Forced"));
             }
         };

http://git-wip-us.apache.org/repos/asf/camel/blob/39663b27/components/camel-hystrix/src/test/java/org/apache/camel/component/hystrix/TryCatchTest.java
----------------------------------------------------------------------
diff --git a/components/camel-hystrix/src/test/java/org/apache/camel/component/hystrix/TryCatchTest.java b/components/camel-hystrix/src/test/java/org/apache/camel/component/hystrix/TryCatchTest.java
new file mode 100644
index 0000000..089b3b8
--- /dev/null
+++ b/components/camel-hystrix/src/test/java/org/apache/camel/component/hystrix/TryCatchTest.java
@@ -0,0 +1,53 @@
+/**
+ * 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.camel.component.hystrix;
+
+import org.apache.camel.builder.RouteBuilder;
+import org.apache.camel.test.junit4.CamelTestSupport;
+import org.junit.Test;
+
+public class TryCatchTest extends CamelTestSupport {
+
+    @Test
+    public void testTryCatch() throws Exception {
+        getMockEndpoint("mock:result").expectedBodiesReceived("Fallback message");
+
+        template.sendBody("direct:start", "Hello World");
+
+        assertMockEndpointsSatisfied();
+    }
+
+    @Override
+    protected RouteBuilder createRouteBuilder() throws Exception {
+        return new RouteBuilder() {
+            @Override
+            public void configure() throws Exception {
+                from("direct:start")
+                    .doTry()
+                        .to("direct:foo")
+                    .doCatch(Exception.class)
+                        .transform().constant("Fallback message")
+                    .end()
+                    .to("mock:result");
+
+                from("direct:foo").errorHandler(noErrorHandler())
+                    .throwException(new IllegalArgumentException("Forced"));
+            }
+        };
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/camel/blob/39663b27/components/camel-hystrix/src/test/resources/log4j.properties
----------------------------------------------------------------------
diff --git a/components/camel-hystrix/src/test/resources/log4j.properties b/components/camel-hystrix/src/test/resources/log4j.properties
index be664b3..2d541ed 100644
--- a/components/camel-hystrix/src/test/resources/log4j.properties
+++ b/components/camel-hystrix/src/test/resources/log4j.properties
@@ -18,7 +18,7 @@
 #
 # The logging properties used for testing.
 #
-log4j.rootLogger=DEBUG, file
+log4j.rootLogger=INFO, file
 
 # uncomment the following to enable camel debugging
 #log4j.logger.org.apache.camel.component.hystrix=DEBUG