From 4e134a02a4b6f30704b99dfb166dc361daf426ea Mon Sep 17 00:00:00 2001
From: Brandon Li <brandonli@apache.org>
Date: Tue, 21 Oct 2014 11:49:10 -0700
Subject: [PATCH] HDFS-7215.Add JvmPauseMonitor to NFS gateway. Contributed by
 Brandon Li

---
 .../org/apache/hadoop/nfs/nfs3/Nfs3Base.java   |  5 +++--
 .../org/apache/hadoop/oncrpc/RpcProgram.java   |  3 ++-
 .../hadoop/hdfs/nfs/nfs3/RpcProgramNfs3.java   | 18 +++++++++++++++++-
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt    |  2 ++
 .../src/site/apt/HdfsNfsGateway.apt.vm         |  4 +++-
 5 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/nfs/nfs3/Nfs3Base.java b/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/nfs/nfs3/Nfs3Base.java
index b166330c79..40744bc16c 100644
--- a/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/nfs/nfs3/Nfs3Base.java
+++ b/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/nfs/nfs3/Nfs3Base.java
@@ -50,7 +50,7 @@ public void start(boolean register) {
     startTCPServer(); // Start TCP server
 
     if (register) {
-      ShutdownHookManager.get().addShutdownHook(new Unregister(),
+      ShutdownHookManager.get().addShutdownHook(new NfsShutdownHook(),
           SHUTDOWN_HOOK_PRIORITY);
       try {
         rpcProgram.register(PortmapMapping.TRANSPORT_TCP, nfsBoundPort);
@@ -74,10 +74,11 @@ private void startTCPServer() {
    */
   public static final int SHUTDOWN_HOOK_PRIORITY = 10;
 
-  private class Unregister implements Runnable {
+  private class NfsShutdownHook implements Runnable {
     @Override
     public synchronized void run() {
       rpcProgram.unregister(PortmapMapping.TRANSPORT_TCP, nfsBoundPort);
+      rpcProgram.stopDaemons();
     }
   }
 }
diff --git a/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/oncrpc/RpcProgram.java b/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/oncrpc/RpcProgram.java
index 3190603593..3343c75e1a 100644
--- a/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/oncrpc/RpcProgram.java
+++ b/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/oncrpc/RpcProgram.java
@@ -136,8 +136,9 @@ protected void register(PortmapMapping mapEntry, boolean set) {
     }
   }
 
-  // Start extra daemons
+  // Start extra daemons or services
   public void startDaemons() {}
+  public void stopDaemons() {}
   
   @Override
   public void messageReceived(ChannelHandlerContext ctx, MessageEvent e)
diff --git a/hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/RpcProgramNfs3.java b/hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/RpcProgramNfs3.java
index 40a9043e7c..b1076f2894 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/RpcProgramNfs3.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/RpcProgramNfs3.java
@@ -126,6 +126,7 @@
 import org.apache.hadoop.security.SecurityUtil;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.authorize.AuthorizationException;
+import org.apache.hadoop.util.JvmPauseMonitor;
 import org.jboss.netty.buffer.ChannelBuffer;
 import org.jboss.netty.buffer.ChannelBuffers;
 import org.jboss.netty.channel.Channel;
@@ -158,6 +159,7 @@ public class RpcProgramNfs3 extends RpcProgram implements Nfs3Interface {
   private String writeDumpDir; // The dir save dump files
 
   private final RpcCallCache rpcCallCache;
+  private JvmPauseMonitor pauseMonitor;
 
   public RpcProgramNfs3(NfsConfiguration config, DatagramSocket registrationSocket,
       boolean allowInsecurePorts) throws IOException {
@@ -219,7 +221,21 @@ private void clearDirectory(String writeDumpDir) throws IOException {
 
   @Override
   public void startDaemons() {
-     writeManager.startAsyncDataSerivce();
+    if (pauseMonitor == null) {
+      pauseMonitor = new JvmPauseMonitor(config);
+      pauseMonitor.start();
+    }
+    writeManager.startAsyncDataSerivce();
+  }
+
+  @Override
+  public void stopDaemons() {
+    if (writeManager != null) {
+      writeManager.shutdownAsyncDataService();
+    }
+    if (pauseMonitor != null) {
+      pauseMonitor.stop();
+    }
   }
 
   // Checks the type of IOException and maps it to appropriate Nfs3Status code.
diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index dd11cf526e..c2b667e14b 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -979,6 +979,8 @@ Release 2.6.0 - UNRELEASED
     HDFS-7259. Unresponseive NFS mount point due to deferred COMMIT response.
     (brandonli)
 
+    HDFS-7215.Add JvmPauseMonitor to NFS gateway (brandonli)
+
     BREAKDOWN OF HDFS-6134 AND HADOOP-10150 SUBTASKS AND RELATED JIRAS
   
       HDFS-6387. HDFS CLI admin tool for creating & deleting an
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/site/apt/HdfsNfsGateway.apt.vm b/hadoop-hdfs-project/hadoop-hdfs/src/site/apt/HdfsNfsGateway.apt.vm
index 4044ae8d50..0e6c482b78 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/site/apt/HdfsNfsGateway.apt.vm
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/site/apt/HdfsNfsGateway.apt.vm
@@ -171,7 +171,9 @@ HDFS NFS Gateway
 </property>
 ----
 
-  * Customize log settings. To get NFS debug trace, users can edit the log4j.property file 
+  * JVM and log settings. You can export JVM settings (e.g., heap size and GC log) in 
+   HADOOP_NFS3_OPTS. More NFS related settings can be found in hadoop-env.sh. 
+   To get NFS debug trace, you can edit the log4j.property file 
    to add the following. Note, debug trace, especially for ONCRPC, can be very verbose.
 
     To change logging level: