[5/8] hbase git commit: HBASE-10378 Refactor write-ahead-log implementation

[st...@apache.org]

http://git-wip-us.apache.org/repos/asf/hbase/blob/f5e05eb8/hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALPrettyPrinter.java
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diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALPrettyPrinter.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALPrettyPrinter.java
new file mode 100644
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@@ -0,0 +1,407 @@
+/**
+ * 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.hadoop.hbase.wal;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.PrintStream;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.commons.cli.CommandLine;
+import org.apache.commons.cli.CommandLineParser;
+import org.apache.commons.cli.HelpFormatter;
+import org.apache.commons.cli.Options;
+import org.apache.commons.cli.ParseException;
+import org.apache.commons.cli.PosixParser;
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.CellUtil;
+import org.apache.hadoop.hbase.HBaseConfiguration;
+import org.apache.hadoop.hbase.Tag;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.codehaus.jackson.map.ObjectMapper;
+
+// imports for things that haven't moved yet.
+import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
+
+/**
+ * WALPrettyPrinter prints the contents of a given WAL with a variety of
+ * options affecting formatting and extent of content.
+ * 
+ * It targets two usage cases: pretty printing for ease of debugging directly by
+ * humans, and JSON output for consumption by monitoring and/or maintenance
+ * scripts.
+ * 
+ * It can filter by row, region, or sequence id.
+ * 
+ * It can also toggle output of values.
+ * 
+ */
+@InterfaceAudience.Private
+public class WALPrettyPrinter {
+  private boolean outputValues;
+  private boolean outputJSON;
+  // The following enable filtering by sequence, region, and row, respectively
+  private long sequence;
+  private String region;
+  private String row;
+  // enable in order to output a single list of transactions from several files
+  private boolean persistentOutput;
+  private boolean firstTxn;
+  // useful for programatic capture of JSON output
+  private PrintStream out;
+  // for JSON encoding
+  private static final ObjectMapper MAPPER = new ObjectMapper();
+
+  /**
+   * Basic constructor that simply initializes values to reasonable defaults.
+   */
+  public WALPrettyPrinter() {
+    outputValues = false;
+    outputJSON = false;
+    sequence = -1;
+    region = null;
+    row = null;
+    persistentOutput = false;
+    firstTxn = true;
+    out = System.out;
+  }
+
+  /**
+   * Fully specified constructor.
+   * 
+   * @param outputValues
+   *          when true, enables output of values along with other log
+   *          information
+   * @param outputJSON
+   *          when true, enables output in JSON format rather than a
+   *          "pretty string"
+   * @param sequence
+   *          when nonnegative, serves as a filter; only log entries with this
+   *          sequence id will be printed
+   * @param region
+   *          when not null, serves as a filter; only log entries from this
+   *          region will be printed
+   * @param row
+   *          when not null, serves as a filter; only log entries from this row
+   *          will be printed
+   * @param persistentOutput
+   *          keeps a single list running for multiple files. if enabled, the
+   *          endPersistentOutput() method must be used!
+   * @param out
+   *          Specifies an alternative to stdout for the destination of this 
+   *          PrettyPrinter's output.
+   */
+  public WALPrettyPrinter(boolean outputValues, boolean outputJSON,
+      long sequence, String region, String row, boolean persistentOutput,
+      PrintStream out) {
+    this.outputValues = outputValues;
+    this.outputJSON = outputJSON;
+    this.sequence = sequence;
+    this.region = region;
+    this.row = row;
+    this.persistentOutput = persistentOutput;
+    if (persistentOutput) {
+      beginPersistentOutput();
+    }
+    this.out = out;
+    this.firstTxn = true;
+  }
+
+  /**
+   * turns value output on
+   */
+  public void enableValues() {
+    outputValues = true;
+  }
+
+  /**
+   * turns value output off
+   */
+  public void disableValues() {
+    outputValues = false;
+  }
+
+  /**
+   * turns JSON output on
+   */
+  public void enableJSON() {
+    outputJSON = true;
+  }
+
+  /**
+   * turns JSON output off, and turns on "pretty strings" for human consumption
+   */
+  public void disableJSON() {
+    outputJSON = false;
+  }
+
+  /**
+   * sets the region by which output will be filtered
+   * 
+   * @param sequence
+   *          when nonnegative, serves as a filter; only log entries with this
+   *          sequence id will be printed
+   */
+  public void setSequenceFilter(long sequence) {
+    this.sequence = sequence;
+  }
+
+  /**
+   * sets the region by which output will be filtered
+   * 
+   * @param region
+   *          when not null, serves as a filter; only log entries from this
+   *          region will be printed
+   */
+  public void setRegionFilter(String region) {
+    this.region = region;
+  }
+
+  /**
+   * sets the region by which output will be filtered
+   * 
+   * @param row
+   *          when not null, serves as a filter; only log entries from this row
+   *          will be printed
+   */
+  public void setRowFilter(String row) {
+    this.row = row;
+  }
+
+  /**
+   * enables output as a single, persistent list. at present, only relevant in
+   * the case of JSON output.
+   */
+  public void beginPersistentOutput() {
+    if (persistentOutput)
+      return;
+    persistentOutput = true;
+    firstTxn = true;
+    if (outputJSON)
+      out.print("[");
+  }
+
+  /**
+   * ends output of a single, persistent list. at present, only relevant in the
+   * case of JSON output.
+   */
+  public void endPersistentOutput() {
+    if (!persistentOutput)
+      return;
+    persistentOutput = false;
+    if (outputJSON)
+      out.print("]");
+  }
+
+  /**
+   * reads a log file and outputs its contents, one transaction at a time, as
+   * specified by the currently configured options
+   * 
+   * @param conf
+   *          the HBase configuration relevant to this log file
+   * @param p
+   *          the path of the log file to be read
+   * @throws IOException
+   *           may be unable to access the configured filesystem or requested
+   *           file.
+   */
+  public void processFile(final Configuration conf, final Path p)
+      throws IOException {
+    FileSystem fs = FileSystem.get(conf);
+    if (!fs.exists(p)) {
+      throw new FileNotFoundException(p.toString());
+    }
+    if (!fs.isFile(p)) {
+      throw new IOException(p + " is not a file");
+    }
+    if (outputJSON && !persistentOutput) {
+      out.print("[");
+      firstTxn = true;
+    }
+    WAL.Reader log = WALFactory.createReader(fs, p, conf);
+    try {
+      WAL.Entry entry;
+      while ((entry = log.next()) != null) {
+        WALKey key = entry.getKey();
+        WALEdit edit = entry.getEdit();
+        // begin building a transaction structure
+        Map<String, Object> txn = key.toStringMap();
+        long writeTime = key.getWriteTime();
+        // check output filters
+        if (sequence >= 0 && ((Long) txn.get("sequence")) != sequence)
+          continue;
+        if (region != null && !((String) txn.get("region")).equals(region))
+          continue;
+        // initialize list into which we will store atomic actions
+        List<Map> actions = new ArrayList<Map>();
+        for (Cell cell : edit.getCells()) {
+          // add atomic operation to txn
+          Map<String, Object> op = new HashMap<String, Object>(toStringMap(cell));
+          if (outputValues) op.put("value", Bytes.toStringBinary(cell.getValue()));
+          // check row output filter
+          if (row == null || ((String) op.get("row")).equals(row))
+            actions.add(op);
+        }
+        if (actions.size() == 0)
+          continue;
+        txn.put("actions", actions);
+        if (outputJSON) {
+          // JSON output is a straightforward "toString" on the txn object
+          if (firstTxn)
+            firstTxn = false;
+          else
+            out.print(",");
+          // encode and print JSON
+          out.print(MAPPER.writeValueAsString(txn));
+        } else {
+          // Pretty output, complete with indentation by atomic action
+          out.println("Sequence " + txn.get("sequence") + " "
+              + "from region " + txn.get("region") + " " + "in table "
+              + txn.get("table") + " at write timestamp: " + new Date(writeTime));
+          for (int i = 0; i < actions.size(); i++) {
+            Map op = actions.get(i);
+            out.println("  Action:");
+            out.println("    row: " + op.get("row"));
+            out.println("    column: " + op.get("family") + ":"
+                + op.get("qualifier"));
+            out.println("    timestamp: "
+                + (new Date((Long) op.get("timestamp"))));
+            if(op.get("tag") != null) {
+              out.println("    tag: " + op.get("tag"));
+            }
+            if (outputValues)
+              out.println("    value: " + op.get("value"));
+          }
+        }
+      }
+    } finally {
+      log.close();
+    }
+    if (outputJSON && !persistentOutput) {
+      out.print("]");
+    }
+  }
+
+  private static Map<String, Object> toStringMap(Cell cell) {
+    Map<String, Object> stringMap = new HashMap<String, Object>();
+    stringMap.put("row",
+        Bytes.toStringBinary(cell.getRowArray(), cell.getRowOffset(), cell.getRowLength()));
+    stringMap.put("family", Bytes.toStringBinary(cell.getFamilyArray(), cell.getFamilyOffset(),
+                cell.getFamilyLength()));
+    stringMap.put("qualifier",
+        Bytes.toStringBinary(cell.getQualifierArray(), cell.getQualifierOffset(),
+            cell.getQualifierLength()));
+    stringMap.put("timestamp", cell.getTimestamp());
+    stringMap.put("vlen", cell.getValueLength());
+    if (cell.getTagsLength() > 0) {
+      List<String> tagsString = new ArrayList<String>();
+      Iterator<Tag> tagsIterator = CellUtil.tagsIterator(cell.getTagsArray(), cell.getTagsOffset(),
+          cell.getTagsLength());
+      while (tagsIterator.hasNext()) {
+        Tag tag = tagsIterator.next();
+        tagsString.add((tag.getType()) + ":"
+            + Bytes.toStringBinary(tag.getBuffer(), tag.getTagOffset(), tag.getTagLength()));
+      }
+      stringMap.put("tag", tagsString);
+    }
+    return stringMap;
+  }
+
+  public static void main(String[] args) throws IOException {
+    run(args);
+  }
+
+  /**
+   * Pass one or more log file names and formatting options and it will dump out
+   * a text version of the contents on <code>stdout</code>.
+   * 
+   * @param args
+   *          Command line arguments
+   * @throws IOException
+   *           Thrown upon file system errors etc.
+   * @throws ParseException
+   *           Thrown if command-line parsing fails.
+   */
+  public static void run(String[] args) throws IOException {
+    // create options
+    Options options = new Options();
+    options.addOption("h", "help", false, "Output help message");
+    options.addOption("j", "json", false, "Output JSON");
+    options.addOption("p", "printvals", false, "Print values");
+    options.addOption("r", "region", true,
+        "Region to filter by. Pass region name; e.g. 'hbase:meta,,1'");
+    options.addOption("s", "sequence", true,
+        "Sequence to filter by. Pass sequence number.");
+    options.addOption("w", "row", true, "Row to filter by. Pass row name.");
+
+    WALPrettyPrinter printer = new WALPrettyPrinter();
+    CommandLineParser parser = new PosixParser();
+    List files = null;
+    try {
+      CommandLine cmd = parser.parse(options, args);
+      files = cmd.getArgList();
+      if (files.size() == 0 || cmd.hasOption("h")) {
+        HelpFormatter formatter = new HelpFormatter();
+        formatter.printHelp("WAL <filename...>", options, true);
+        System.exit(-1);
+      }
+      // configure the pretty printer using command line options
+      if (cmd.hasOption("p"))
+        printer.enableValues();
+      if (cmd.hasOption("j"))
+        printer.enableJSON();
+      if (cmd.hasOption("r"))
+        printer.setRegionFilter(cmd.getOptionValue("r"));
+      if (cmd.hasOption("s"))
+        printer.setSequenceFilter(Long.parseLong(cmd.getOptionValue("s")));
+      if (cmd.hasOption("w"))
+        printer.setRowFilter(cmd.getOptionValue("w"));
+    } catch (ParseException e) {
+      e.printStackTrace();
+      HelpFormatter formatter = new HelpFormatter();
+      formatter.printHelp("HFile filename(s) ", options, true);
+      System.exit(-1);
+    }
+    // get configuration, file system, and process the given files
+    Configuration conf = HBaseConfiguration.create();
+    FSUtils.setFsDefault(conf, FSUtils.getRootDir(conf));
+
+    // begin output
+    printer.beginPersistentOutput();
+    for (Object f : files) {
+      Path file = new Path((String) f);
+      FileSystem fs = file.getFileSystem(conf);
+      if (!fs.exists(file)) {
+        System.err.println("ERROR, file doesnt exist: " + file);
+        return;
+      }
+      printer.processFile(conf, file);
+    }
+    printer.endPersistentOutput();
+  }
+}

http://git-wip-us.apache.org/repos/asf/hbase/blob/f5e05eb8/hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALProvider.java
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diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALProvider.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALProvider.java
new file mode 100644
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+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALProvider.java
@@ -0,0 +1,83 @@
+/**
+ *
+ * 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.hadoop.hbase.wal;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configuration;
+
+// imports for things that haven't moved from regionserver.wal yet.
+import org.apache.hadoop.hbase.regionserver.wal.WALActionsListener;
+
+/**
+ * The Write Ahead Log (WAL) stores all durable edits to the HRegion.
+ * This interface provides the entry point for all WAL implementors.
+ * <p>
+ * See {@link DefaultWALProvider} for an example implementation.
+ *
+ * A single WALProvider will be used for retrieving multiple WALs in a particular region server
+ * and must be threadsafe.
+ */
+@InterfaceAudience.Private
+public interface WALProvider {
+
+  /**
+   * Set up the provider to create wals.
+   * will only be called once per instance.
+   * @param factory factory that made us may not be null
+   * @param conf may not be null
+   * @param listeners may be null
+   * @param providerId differentiate between providers from one factory. may be null
+   */
+  void init(final WALFactory factory, final Configuration conf,
+      final List<WALActionsListener> listeners, final String providerId) throws IOException;
+
+  /**
+   * @param identifier may not be null. contents will not be altered.
+   * @return a WAL for writing entries for the given region.
+   */
+  WAL getWAL(final byte[] identifier) throws IOException;
+
+  /**
+   * persist outstanding WALs to storage and stop accepting new appends.
+   * This method serves as shorthand for sending a sync to every WAL provided by a given
+   * implementation. Those WALs will also stop accepting new writes.
+   */
+  void shutdown() throws IOException;
+
+  /**
+   * shutdown utstanding WALs and clean up any persisted state.
+   * Call this method only when you will not need to replay any of the edits to the WALs from
+   * this provider. After this call completes, the underlying resources should have been reclaimed.
+   */
+  void close() throws IOException;
+
+  // Writers are used internally. Users outside of the WAL should be relying on the
+  // interface provided by WAL.
+  interface Writer extends Closeable {
+    void sync() throws IOException;
+    void append(WAL.Entry entry) throws IOException;
+    long getLength() throws IOException;
+  }
+
+}