HDFS-3796. Speed up edit log tests by avoiding fsync(). Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1373567 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -397,6 +397,8 @@ Branch-2 ( Unreleased changes )
     HDFS-3802. StartupOption.name in HdfsServerConstants should be final.
     (Jing Zhao via szetszwo)
 
+    HDFS-3796. Speed up edit log tests by avoiding fsync() (todd)
+
   OPTIMIZATIONS
 
     HDFS-2982. Startup performance suffers when there are many edit log

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/EditLogFileOutputStream.java

@@ -49,6 +49,8 @@ public class EditLogFileOutputStream extends EditLogOutputStream {
   private EditsDoubleBuffer doubleBuf;
   static ByteBuffer fill = ByteBuffer.allocateDirect(MIN_PREALLOCATION_LENGTH);
 
+  private static boolean shouldSkipFsyncForTests = false;
+
   static {
     fill.position(0);
     for (int i = 0; i < fill.capacity(); i++) {
@@ -184,7 +186,9 @@ public class EditLogFileOutputStream extends EditLogOutputStream {
     }
     preallocate(); // preallocate file if necessay
     doubleBuf.flushTo(fp);
-    fc.force(false); // metadata updates not needed
+    if (!shouldSkipFsyncForTests) {
+      fc.force(false); // metadata updates not needed
+    }
   }
 
   /**
@@ -247,4 +251,15 @@ public class EditLogFileOutputStream extends EditLogOutputStream {
   public FileChannel getFileChannelForTesting() {
     return fc;
   }
+  
+  /**
+   * For the purposes of unit tests, we don't need to actually
+   * write durably to disk. So, we can skip the fsync() calls
+   * for a speed improvement.
+   * @param skip true if fsync should <em>not</em> be called
+   */
+  @VisibleForTesting
+  public static void setShouldSkipFsyncForTesting(boolean skip) {
+    shouldSkipFsyncForTests = skip;
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestEditLog.java

@@ -119,6 +119,11 @@ public class TestEditLog {
         "a4ff 0000 0000 0000 0000 0000 0000 0000"
     ).replace(" ",""));
 
+  static {
+    // No need to fsync for the purposes of tests. This makes
+    // the tests run much faster.
+    EditLogFileOutputStream.setShouldSkipFsyncForTesting(true);
+  }
   
   static final byte TRAILER_BYTE = FSEditLogOpCodes.OP_INVALID.getOpCode();
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestEditLogFileOutputStream.java

@@ -40,6 +40,12 @@ public class TestEditLogFileOutputStream {
   final static int MIN_PREALLOCATION_LENGTH =
       EditLogFileOutputStream.MIN_PREALLOCATION_LENGTH;
 
+  static {
+    // No need to fsync for the purposes of tests. This makes
+    // the tests run much faster.
+    EditLogFileOutputStream.setShouldSkipFsyncForTesting(true);
+  }
+
   @Before
   @After
   public void deleteEditsFile() {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFileJournalManager.java

@@ -51,6 +51,12 @@ import com.google.common.collect.ImmutableList;
 public class TestFileJournalManager {
   static final Log LOG = LogFactory.getLog(TestFileJournalManager.class);
 
+  static {
+    // No need to fsync for the purposes of tests. This makes
+    // the tests run much faster.
+    EditLogFileOutputStream.setShouldSkipFsyncForTesting(true);
+  }
+
   /**
    * Find out how many transactions we can read from a
    * FileJournalManager, starting at a given transaction ID.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNameNodeRecovery.java

@@ -57,6 +57,7 @@ public class TestNameNodeRecovery {
 
   static {
     recoverStartOpt.setForce(MetaRecoveryContext.FORCE_ALL);
+    EditLogFileOutputStream.setShouldSkipFsyncForTesting(true);
   }
 
   static void runEditLogTest(EditLogTestSetup elts) throws IOException {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestSecurityTokenEditLog.java

@@ -49,6 +49,12 @@ public class TestSecurityTokenEditLog {
   static final int NUM_THREADS = 100;
   static final int opsPerTrans = 3;
 
+  static {
+    // No need to fsync for the purposes of tests. This makes
+    // the tests run much faster.
+    EditLogFileOutputStream.setShouldSkipFsyncForTesting(true);
+  }
+
   //
   // an object that does a bunch of transactions
   //

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestEditLogsDuringFailover.java

@@ -34,6 +34,7 @@ import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.HAUtil;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.MiniDFSNNTopology;
+import org.apache.hadoop.hdfs.server.namenode.EditLogFileOutputStream;
 import org.apache.hadoop.hdfs.server.namenode.FSImageTestUtil;
 import org.apache.hadoop.hdfs.server.namenode.NNStorage;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
@@ -53,6 +54,12 @@ public class TestEditLogsDuringFailover {
     LogFactory.getLog(TestEditLogsDuringFailover.class);
   private static final int NUM_DIRS_IN_LOG = 5;
 
+  static {
+    // No need to fsync for the purposes of tests. This makes
+    // the tests run much faster.
+    EditLogFileOutputStream.setShouldSkipFsyncForTesting(true);
+  }
+  
   @Test
   public void testStartup() throws Exception {
     Configuration conf = new Configuration();