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Posted to commits@hbase.apache.org by st...@apache.org on 2011/06/04 21:46:00 UTC

svn commit: r1131480 - in /hbase/trunk: CHANGES.txt src/main/java/org/apache/hadoop/hbase/io/WritableDelayed.java src/main/java/org/apache/hadoop/hbase/ipc/HBaseServer.java

Author: stack
Date: Sat Jun  4 19:46:00 2011
New Revision: 1131480

URL: http://svn.apache.org/viewvc?rev=1131480&view=rev
Log:
HBASE-3899 enhance HBase RPC to support free-ing up server handler threads even if response is not ready -- BACKED IT OUT

Modified:
    hbase/trunk/CHANGES.txt
    hbase/trunk/src/main/java/org/apache/hadoop/hbase/io/WritableDelayed.java
    hbase/trunk/src/main/java/org/apache/hadoop/hbase/ipc/HBaseServer.java

Modified: hbase/trunk/CHANGES.txt
URL: http://svn.apache.org/viewvc/hbase/trunk/CHANGES.txt?rev=1131480&r1=1131479&r2=1131480&view=diff
==============================================================================
--- hbase/trunk/CHANGES.txt (original)
+++ hbase/trunk/CHANGES.txt Sat Jun  4 19:46:00 2011
@@ -276,8 +276,6 @@ Release 0.91.0 - Unreleased
                RS web UIs
    HBASE-3691  Add compressor support for 'snappy', google's compressor
                (Nichole Treadway and Nicholas Telford)
-   HBASE-3899  enhance HBase RPC to support free-ing up server handler threads
-               even if response is not ready (Dhruba Borthakur)
 
 
 Release 0.90.4 - Unreleased

Modified: hbase/trunk/src/main/java/org/apache/hadoop/hbase/io/WritableDelayed.java
URL: http://svn.apache.org/viewvc/hbase/trunk/src/main/java/org/apache/hadoop/hbase/io/WritableDelayed.java?rev=1131480&r1=1131479&r2=1131480&view=diff
==============================================================================
--- hbase/trunk/src/main/java/org/apache/hadoop/hbase/io/WritableDelayed.java (original)
+++ hbase/trunk/src/main/java/org/apache/hadoop/hbase/io/WritableDelayed.java Sat Jun  4 19:46:00 2011
@@ -1,33 +0,0 @@
-/*
- * Copyright 2010 The Apache Software Foundation
- *
- * 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.io;
-
-/**
- * An optional interface to indicate the the values are not immediately
- * readable.
- */
-public interface WritableDelayed {
-  /**
-   * Provide a hint to the caller to indicate that
-   * data is not ready yet.
-   */
-  public boolean isDelayed();
-}

Modified: hbase/trunk/src/main/java/org/apache/hadoop/hbase/ipc/HBaseServer.java
URL: http://svn.apache.org/viewvc/hbase/trunk/src/main/java/org/apache/hadoop/hbase/ipc/HBaseServer.java?rev=1131480&r1=1131479&r2=1131480&view=diff
==============================================================================
--- hbase/trunk/src/main/java/org/apache/hadoop/hbase/ipc/HBaseServer.java (original)
+++ hbase/trunk/src/main/java/org/apache/hadoop/hbase/ipc/HBaseServer.java Sat Jun  4 19:46:00 2011
@@ -57,7 +57,6 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.io.WritableWithSize;
-import org.apache.hadoop.hbase.io.WritableDelayed;
 import org.apache.hadoop.hbase.util.ByteBufferOutputStream;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.io.Writable;
@@ -98,7 +97,7 @@ public abstract class HBaseServer implem
   /** Default value for above param */
   private static final int DEFAULT_WARN_RESPONSE_SIZE = 100 * 1024 * 1024;
 
-  private static int warnResponseSize;
+  private final int warnResponseSize;
 
   public static final Log LOG =
     LogFactory.getLog("org.apache.hadoop.ipc.HBaseServer");
@@ -151,25 +150,6 @@ public abstract class HBaseServer implem
     }
     return null;
   }
-  /**
-   * If invoked from inside an RPC, startDelay tells the current call to not 
-   * send out * responses back to the client until endDelay() is invoked.
-   */
-  public static void startDelay(Object o) {
-    Call call = (Call) o;
-    if (call != null) {
-      call.startDelay();
-    }
-  }
-  public static void endDelay(Object o) throws IOException {
-    Call call = (Call) o;
-    if (call != null) {
-      call.endDelay();
-    }
-  }
-  public static Object getCall() {
-    return CurCall.get();
-  }
   /** Returns remote address as a string when invoked inside an RPC.
    *  Returns null in case of an error.
    *  @return String
@@ -261,19 +241,13 @@ public abstract class HBaseServer implem
     protected long timestamp;      // the time received when response is null
                                    // the time served when response is not null
     protected ByteBuffer response;                // the response for this call
-    private boolean delayResponse; // shall the RPC layer delay the response?
-    private boolean doneResponse;  // have we already responded to the client?
-    private Responder responder;   // the thread that sends out responses
 
-    public Call(int id, Writable param, Connection connection, Responder responder) {
+    public Call(int id, Writable param, Connection connection) {
       this.id = id;
       this.param = param;
       this.connection = connection;
       this.timestamp = System.currentTimeMillis();
       this.response = null;
-      this.delayResponse = false;
-      this.doneResponse = false;
-      this.responder = responder;
     }
 
     @Override
@@ -281,40 +255,9 @@ public abstract class HBaseServer implem
       return param.toString() + " from " + connection.toString();
     }
 
-    public synchronized void setResponse(ByteBuffer response) {
+    public void setResponse(ByteBuffer response) {
       this.response = response;
     }
-
-    /**
-     * Delay this call, do not send its response back to the client
-     */
-    public synchronized void startDelay() {
-      this.delayResponse = true;
-    }
-
-    /**
-     * It is ok to send responses back to the client now. This is
-     * typically called by a non-server-handler thread.
-     */
-    public synchronized void endDelay() throws IOException {
-      this.delayResponse = false;
-      if (response != null && !doneResponse) {
-        doneResponse = true;
-        responder.doRespond(this);
-      }
-    }
-
-    /*
-     * If we have a reponse, and delay is not set, then respond
-     * immediately. Otherwise, do not respond to client. This is
-     * called the by the RPC code in the context of the Handler thread.
-     */
-    public synchronized void sendResponseIfReady() throws IOException {
-      if (response != null && !doneResponse && !delayResponse) {
-        doneResponse = true; // going to respond as soon as this call returns.
-        responder.doRespond(this);
-      }
-    }
   }
 
   /** Listens on the socket. Creates jobs for the handler threads*/
@@ -857,40 +800,15 @@ public abstract class HBaseServer implem
     }
 
     //
-    // Enqueue for background thread to send responses out later.
-    //
-    private void enqueueInSelector(Call call) throws IOException {
-      incPending();
-      try {
-        // Wakeup the thread blocked on select, only then can the call
-        // to channel.register() complete.
-        SocketChannel channel = call.connection.channel;
-        writeSelector.wakeup();
-        channel.register(writeSelector, SelectionKey.OP_WRITE, call);
-       } catch (ClosedChannelException e) {
-         //Its ok. channel might be closed else where.
-       } finally {
-         decPending();
-       }
-    }
-
-    //
     // Enqueue a response from the application.
     //
     void doRespond(Call call) throws IOException {
-      // set the serve time when the response has to be sent later
-      call.timestamp = System.currentTimeMillis();
-
-      boolean doRegister = false;
       synchronized (call.connection.responseQueue) {
         call.connection.responseQueue.addLast(call);
         if (call.connection.responseQueue.size() == 1) {
-          doRegister = !processResponse(call.connection.responseQueue, false);
+          processResponse(call.connection.responseQueue, true);
         }
       }
-      if (doRegister) {
-        enqueueInSelector(call); // tell background thread to send it out later
-      }
     }
 
     private synchronized void incPending() {   // call waiting to be enqueued.
@@ -1085,7 +1003,7 @@ public abstract class HBaseServer implem
       Writable param = ReflectionUtils.newInstance(paramClass, conf);           // read param
       param.readFields(dis);
 
-      Call call = new Call(id, param, this, responder);
+      Call call = new Call(id, param, this);
 
       if (priorityCallQueue != null && getQosLevel(param) > highPriorityLevel) {
         priorityCallQueue.put(call);
@@ -1152,10 +1070,6 @@ public abstract class HBaseServer implem
           }
           CurCall.set(null);
 
-          if (!(value instanceof WritableDelayed)) {
-            processRpcResponse(call, value, error, errorClass);
-          }
-
           int size = BUFFER_INITIAL_SIZE;
           if (value instanceof WritableWithSize) {
             // get the size hint.
@@ -1192,7 +1106,7 @@ public abstract class HBaseServer implem
 
 
           call.setResponse(buf.getByteBuffer());
-          call.sendResponseIfReady(); // maybe delay sending out response to the client
+          responder.doRespond(call);
         } catch (InterruptedException e) {
           if (running) {                          // unexpected -- log it
             LOG.info(getName() + " caught: " +
@@ -1218,51 +1132,6 @@ public abstract class HBaseServer implem
 
   }
 
-  // Packages the rpc invocation response back into the call.
-  static public void processRpcResponse(Object callobj, Writable value,
-    String error, String errorClass) throws IOException {
-    Call call = (Call)callobj;
-
-    int size = Handler.BUFFER_INITIAL_SIZE;
-    if (value instanceof WritableWithSize) {
-      // get the size hint.
-      WritableWithSize ohint = (WritableWithSize)value;
-      long hint = ohint.getWritableSize() + Bytes.SIZEOF_BYTE + Bytes.SIZEOF_INT;
-      if (hint > 0) {
-        if ((hint) > Integer.MAX_VALUE) {
-          // oops, new problem.
-          IOException ioe = 
-            new IOException("Result buffer size too large: " + hint);
-          errorClass = ioe.getClass().getName();
-          error = StringUtils.stringifyException(ioe);
-        } else {
-          size = (int)hint;
-        }
-      }
-    }
-    ByteBufferOutputStream buf = new ByteBufferOutputStream(size);
-    DataOutputStream out = new DataOutputStream(buf);
-    out.writeInt(call.id);                // write call id
-    out.writeBoolean(error != null);      // write error flag
-
-    if (error == null) {
-      value.write(out);
-    } else {
-      WritableUtils.writeString(out, errorClass);
-      WritableUtils.writeString(out, error);
-    }
-
-    if (buf.size() > warnResponseSize) {
-      LOG.warn("responseTooLarge for: "+call+": Size: "
-                     + StringUtils.humanReadableInt(buf.size()));
-    }
-    if (LOG.isDebugEnabled()) {
-      LOG.debug("Served: " + ((Invocation)call.param).getMethodName());
-    }
-    call.setResponse(buf.getByteBuffer());
-    call.sendResponseIfReady(); // maybe delay sending out response to the client
-  }
-
   /**
    * Gets the QOS level for this call.  If it is higher than the highPriorityLevel and there
    * are priorityHandlers available it will be processed in it's own thread set.