HDFS-7929. inotify unable fetch pre-upgrade edit log segments once upgrade starts (Zhe Zhang via Colin P. McCabe)

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

@@ -1202,6 +1202,9 @@ Release 2.7.0 - UNRELEASED
     HDFS-7943. Append cannot handle the last block with length greater than
     the preferred block size. (jing9)
 
+    HDFS-7929. inotify unable fetch pre-upgrade edit log segments once upgrade
+    starts (Zhe Zhang via Colin P. McCabe)
+
     BREAKDOWN OF HDFS-7584 SUBTASKS AND RELATED JIRAS
 
       HDFS-7720. Quota by Storage Type API, tools and ClientNameNode

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

@@ -406,7 +406,7 @@ void doUpgrade(FSNamesystem target) throws IOException {
     for (Iterator<StorageDirectory> it = storage.dirIterator(false); it.hasNext();) {
       StorageDirectory sd = it.next();
       try {
-        NNUpgradeUtil.doPreUpgrade(sd);
+        NNUpgradeUtil.doPreUpgrade(conf, sd);
       } catch (Exception e) {
         LOG.error("Failed to move aside pre-upgrade storage " +
             "in image directory " + sd.getRoot(), e);

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

@@ -581,7 +581,7 @@ public String toString() {
   public void doPreUpgrade() throws IOException {
     LOG.info("Starting upgrade of edits directory " + sd.getRoot());
     try {
-     NNUpgradeUtil.doPreUpgrade(sd);
+     NNUpgradeUtil.doPreUpgrade(conf, sd);
     } catch (IOException ioe) {
      LOG.error("Failed to move aside pre-upgrade storage " +
          "in image directory " + sd.getRoot(), ioe);

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

@@ -18,15 +18,19 @@
 package org.apache.hadoop.hdfs.server.namenode;
 
 import java.io.File;
+import java.io.FilenameFilter;
 import java.io.IOException;
+import java.util.List;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.server.common.Storage;
 import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory;
 import org.apache.hadoop.hdfs.server.common.StorageInfo;
 
 import com.google.common.base.Preconditions;
+import org.apache.hadoop.io.IOUtils;
 
 abstract class NNUpgradeUtil {
   
@@ -100,14 +104,16 @@ static void doFinalize(StorageDirectory sd) throws IOException {
    * doUpgrade will not be called for any JM. The existing current dir is
    * renamed to previous.tmp, and then a new, empty current dir is created.
    *
+   * @param conf configuration for creating {@link EditLogFileOutputStream}
    * @param sd the storage directory to perform the pre-upgrade procedure.
    * @throws IOException in the event of error
    */
-  static void doPreUpgrade(StorageDirectory sd) throws IOException {
+  static void doPreUpgrade(Configuration conf, StorageDirectory sd)
+      throws IOException {
     LOG.info("Starting upgrade of storage directory " + sd.getRoot());
     File curDir = sd.getCurrentDir();
     File prevDir = sd.getPreviousDir();
-    File tmpDir = sd.getPreviousTmp();
+    final File tmpDir = sd.getPreviousTmp();
 
     Preconditions.checkState(curDir.exists(),
         "Current directory must exist for preupgrade.");
@@ -123,6 +129,35 @@ static void doPreUpgrade(StorageDirectory sd) throws IOException {
     if (!curDir.mkdir()) {
       throw new IOException("Cannot create directory " + curDir);
     }
+
+    List<String> fileNameList = IOUtils.listDirectory(tmpDir, new FilenameFilter() {
+      @Override
+      public boolean accept(File dir, String name) {
+        return dir.equals(tmpDir)
+            && name.startsWith(NNStorage.NameNodeFile.EDITS.getName());
+      }
+    });
+
+    for (String s : fileNameList) {
+      File prevFile = new File(tmpDir, s);
+      Preconditions.checkState(prevFile.canRead(),
+          "Edits log file " + s + " is not readable.");
+      File newFile = new File(curDir, prevFile.getName());
+      Preconditions.checkState(newFile.createNewFile(),
+          "Cannot create new edits log file in " + curDir);
+      EditLogFileInputStream in = new EditLogFileInputStream(prevFile);
+      EditLogFileOutputStream out =
+          new EditLogFileOutputStream(conf, newFile, 512*1024);
+      FSEditLogOp logOp = in.nextValidOp();
+      while (logOp != null) {
+        out.write(logOp);
+        logOp = in.nextOp();
+      }
+      out.setReadyToFlush();
+      out.flushAndSync(true);
+      out.close();
+      in.close();
+    }
   }
   
   /**

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSUpgrade.java

@@ -28,7 +28,10 @@
 import static org.junit.Assert.fail;
 
 import java.io.File;
+import java.io.FilenameFilter;
 import java.io.IOException;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.regex.Pattern;
 
 import org.apache.commons.logging.Log;
@@ -42,7 +45,9 @@
 import org.apache.hadoop.hdfs.server.common.InconsistentFSStateException;
 import org.apache.hadoop.hdfs.server.common.Storage;
 import org.apache.hadoop.hdfs.server.common.StorageInfo;
+import org.apache.hadoop.hdfs.server.namenode.NNStorage;
 import org.apache.hadoop.hdfs.server.namenode.TestParallelImageWrite;
+import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.ipc.RemoteException;
 import org.apache.hadoop.util.StringUtils;
 import org.junit.BeforeClass;
@@ -451,6 +456,49 @@ public void test203LayoutVersion() {
     }
   }
 
+  @Test
+  public void testPreserveEditLogs() throws Exception {
+    conf = new HdfsConfiguration();
+    conf = UpgradeUtilities.initializeStorageStateConf(1, conf);
+    String[] nameNodeDirs = conf.getStrings(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY);
+    conf.setBoolean(DFSConfigKeys.DFS_DATANODE_DUPLICATE_REPLICA_DELETION, false);
+
+    log("Normal NameNode upgrade", 1);
+    File[] created =
+        UpgradeUtilities.createNameNodeStorageDirs(nameNodeDirs, "current");
+    List<String> beforeUpgrade = new LinkedList<>();
+    for (final File createdDir : created) {
+      List<String> fileNameList =
+          IOUtils.listDirectory(createdDir, EditLogsFilter.INSTANCE);
+      beforeUpgrade.addAll(fileNameList);
+    }
+
+    cluster = createCluster();
+
+    List<String> afterUpgrade = new LinkedList<>();
+    for (final File createdDir : created) {
+      List<String> fileNameList =
+          IOUtils.listDirectory(createdDir, EditLogsFilter.INSTANCE);
+      afterUpgrade.addAll(fileNameList);
+    }
+
+    for (String s : beforeUpgrade) {
+      assertTrue(afterUpgrade.contains(s));
+    }
+
+    cluster.shutdown();
+    UpgradeUtilities.createEmptyDirs(nameNodeDirs);
+  }
+
+  private static enum EditLogsFilter implements FilenameFilter {
+    INSTANCE;
+
+    @Override
+    public boolean accept(File dir, String name) {
+      return name.startsWith(NNStorage.NameNodeFile.EDITS.getName());
+    }
+  }
+
   public static void main(String[] args) throws Exception {
     TestDFSUpgrade t = new TestDFSUpgrade();
     TestDFSUpgrade.initialize();