HBASE-5973. Add ability for potentially long-running IPC calls to abort if client disconnects. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1336787 13f79535-47bb-0310-9956-ffa450edef68

src/main/java/org/apache/hadoop/hbase/ipc/CallerDisconnectedException.java

@@ -0,0 +1,35 @@
+/**
+ * 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.ipc;
+
+import java.io.IOException;
+
+/**
+ * Exception indicating that the remote host making this IPC lost its
+ * IPC connection. This will never be returned back to a client,
+ * but is only used for logging on the server side, etc.
+ */
+public class CallerDisconnectedException extends IOException {
+  public CallerDisconnectedException(String msg) {
+    super(msg);
+  }
+
+  private static final long serialVersionUID = 1L;
+
+  
+}

src/main/java/org/apache/hadoop/hbase/ipc/HBaseServer.java

@@ -271,7 +271,7 @@ public abstract class HBaseServer implements RpcServer {
   }
 
   /** A call queued for handling. */
-  protected class Call implements Delayable {
+  protected class Call implements RpcCallContext {
     protected int id;                             // the client's call id
     protected Writable param;                     // the parameter passed
     protected Connection connection;              // connection to client
@@ -415,6 +415,16 @@ public abstract class HBaseServer implements RpcServer {
       return this.delayReturnValue;
     }
     
+    @Override
+    public void throwExceptionIfCallerDisconnected() throws CallerDisconnectedException {
+      if (!connection.channel.isOpen()) {
+        long afterTime = System.currentTimeMillis() - timestamp;
+        throw new CallerDisconnectedException(
+            "Aborting call " + this + " after " + afterTime + " ms, since " +
+            "caller disconnected");
+      }
+    }
+
     public long getSize() {
       return this.size;
     }
@@ -1768,7 +1778,12 @@ public abstract class HBaseServer implements RpcServer {
     return (nBytes > 0) ? nBytes : ret;
   }
 
-  public Delayable getCurrentCall() {
+  /**
+   * Needed for delayed calls.  We need to be able to store the current call
+   * so that we can complete it later.
+   * @return Call the server is currently handling.
+   */
+  public static RpcCallContext getCurrentCall() {
     return CurCall.get();
   }
 }

src/main/java/org/apache/hadoop/hbase/ipc/RpcCallContext.java

@@ -0,0 +1,29 @@
+/**
+ * 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.ipc;
+
+public interface RpcCallContext extends Delayable {
+
+  /**
+   * Throw an exception if the caller who made this IPC call has disconnected.
+   * If called from outside the context of IPC, this does nothing.
+   * @throws CallerDisconnectedException
+   */
+  void throwExceptionIfCallerDisconnected() throws CallerDisconnectedException;
+
+}

src/main/java/org/apache/hadoop/hbase/ipc/RpcServer.java

@@ -62,12 +62,6 @@ public interface RpcServer {
 
   void startThreads();
 
-  /**
-   * Needed for delayed calls.  We need to be able to store the current call
-   * so that we can complete it later.
-   * @return Call the server is currently handling.
-   */
-  Delayable getCurrentCall();
 
   /**
    * Returns the metrics instance for reporting RPC call statistics

src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java

@@ -106,6 +106,8 @@ import org.apache.hadoop.hbase.io.hfile.BlockCache;
 import org.apache.hadoop.hbase.io.hfile.CacheConfig;
 import org.apache.hadoop.hbase.ipc.CoprocessorProtocol;
 import org.apache.hadoop.hbase.ipc.HBaseRPC;
+import org.apache.hadoop.hbase.ipc.HBaseServer;
+import org.apache.hadoop.hbase.ipc.RpcCallContext;
 import org.apache.hadoop.hbase.monitoring.MonitoredTask;
 import org.apache.hadoop.hbase.monitoring.TaskMonitor;
 import org.apache.hadoop.hbase.regionserver.compactions.CompactionRequest;
@@ -3441,7 +3443,16 @@ public class HRegion implements HeapSize { // , Writable{
     }
 
     private boolean nextInternal(int limit, String metric) throws IOException {
+      RpcCallContext rpcCall = HBaseServer.getCurrentCall();
       while (true) {
+        if (rpcCall != null) {
+          // If a user specifies a too-restrictive or too-slow scanner, the
+          // client might time out and disconnect while the server side
+          // is still processing the request. We should abort aggressively
+          // in that case.
+          rpcCall.throwExceptionIfCallerDisconnected();
+        }
+        
         byte [] currentRow = peekRow();
         if (isStopRow(currentRow)) {
           if (filter != null && filter.hasFilterRow()) {

src/main/ruby/hbase/table.rb

@@ -307,7 +307,8 @@ EOF
         stoprow = args["STOPROW"]
         timestamp = args["TIMESTAMP"]
         columns = args["COLUMNS"] || args["COLUMN"] || []
-        cache = args["CACHE_BLOCKS"] || true
+        cache_blocks = args["CACHE_BLOCKS"] || true
+        cache = args["CACHE"] || 0
         versions = args["VERSIONS"] || 1
         timerange = args[TIMERANGE]
         raw = args["RAW"] || false
@@ -340,7 +341,8 @@ EOF
         end
 
         scan.setTimeStamp(timestamp) if timestamp
-        scan.setCacheBlocks(cache)
+        scan.setCacheBlocks(cache_blocks)
+        scan.setCaching(cache) if cache > 0
         scan.setMaxVersions(versions) if versions > 1
         scan.setTimeRange(timerange[0], timerange[1]) if timerange
         scan.setRaw(raw)

src/main/ruby/shell/commands/scan.rb

@@ -26,7 +26,7 @@ module Shell
 Scan a table; pass table name and optionally a dictionary of scanner
 specifications.  Scanner specifications may include one or more of:
 TIMERANGE, FILTER, LIMIT, STARTROW, STOPROW, TIMESTAMP, MAXLENGTH,
-or COLUMNS.
+or COLUMNS, CACHE
 
 If no columns are specified, all columns will be scanned.
 To scan all members of a column family, leave the qualifier empty as in

src/test/java/org/apache/hadoop/hbase/filter/TestFilter.java

@@ -20,6 +20,8 @@
 
 package org.apache.hadoop.hbase.filter;
 
+import java.io.DataInput;
+import java.io.DataOutput;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -41,12 +43,14 @@ import org.apache.hadoop.hbase.regionserver.wal.HLog;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.junit.experimental.categories.Category;
 
+import com.google.common.base.Throwables;
+
 /**
  * Test filters at the HRegion doorstep.
  */
 @Category(SmallTests.class)
 public class TestFilter extends HBaseTestCase {
-  private final Log LOG = LogFactory.getLog(this.getClass());
+  private final static Log LOG = LogFactory.getLog(TestFilter.class);
   private HRegion region;
 
   //
@@ -1617,6 +1621,41 @@ public class TestFilter extends HBaseTestCase {
     }
   }
   
+  /**
+   * Filter which makes sleeps for a second between each row of a scan.
+   * This can be useful for manual testing of bugs like HBASE-5973. For example:
+   * <code>
+   * create 't1', 'f1'
+   * 1.upto(100)  { |x| put 't1', 'r' + x.to_s, 'f1:q1', 'hi' }
+   * import org.apache.hadoop.hbase.filter.TestFilter
+   * scan 't1', { FILTER => TestFilter::SlowScanFilter.new(), CACHE => 50 }
+   * </code>
+   */
+  public static class SlowScanFilter extends FilterBase {
+    private static Thread ipcHandlerThread = null;
+    
+    @Override
+    public void readFields(DataInput arg0) throws IOException {
+    }
+
+    @Override
+    public void write(DataOutput arg0) throws IOException {
+    }
+
+    @Override
+    public boolean filterRow() {
+      ipcHandlerThread = Thread.currentThread();
+      try {
+        LOG.info("Handler thread " + ipcHandlerThread + " sleeping in filter...");
+        Thread.sleep(1000);
+      } catch (InterruptedException e) {
+        Throwables.propagate(e);
+      }
+      return super.filterRow();
+    }
+  }
+
+
   @org.junit.Rule
   public org.apache.hadoop.hbase.ResourceCheckerJUnitRule cu =
     new org.apache.hadoop.hbase.ResourceCheckerJUnitRule();

src/test/java/org/apache/hadoop/hbase/ipc/TestDelayedRpc.java

@@ -187,7 +187,7 @@ public class TestDelayedRpc {
       if (!delay) {
         return UNDELAYED;
       }
-      final Delayable call = rpcServer.getCurrentCall();
+      final Delayable call = HBaseServer.getCurrentCall();
       call.startDelay(delayReturnValue);
       new Thread() {
         public void run() {
@@ -289,7 +289,7 @@ public class TestDelayedRpc {
     public int test(boolean delay) {
       if (!delay)
         return UNDELAYED;
-      Delayable call = rpcServer.getCurrentCall();
+      Delayable call = HBaseServer.getCurrentCall();
       call.startDelay(true);
       try {
         call.endDelayThrowing(new Exception("Something went wrong"));