HBASE-11610 Enhance remote meta updates

hbase-client/src/main/java/org/apache/hadoop/hbase/client/RpcRetryingCallerFactory.java

@@ -47,9 +47,12 @@ public class RpcRetryingCallerFactory {
   }
 
   public static RpcRetryingCallerFactory instantiate(Configuration configuration) {
+    String clazzName = RpcRetryingCallerFactory.class.getName();
     String rpcCallerFactoryClazz =
-        configuration.get(RpcRetryingCallerFactory.CUSTOM_CALLER_CONF_KEY,
-          RpcRetryingCallerFactory.class.getName());
+        configuration.get(RpcRetryingCallerFactory.CUSTOM_CALLER_CONF_KEY, clazzName);
+    if (rpcCallerFactoryClazz.equals(clazzName)) {
+      return new RpcRetryingCallerFactory(configuration);
+    }
     return ReflectionUtils.instantiateWithCustomCtor(rpcCallerFactoryClazz,
       new Class[] { Configuration.class }, new Object[] { configuration });
   }

hbase-server/src/main/java/org/apache/hadoop/hbase/master/RegionStateStore.java

@@ -18,10 +18,12 @@
 package org.apache.hadoop.hbase.master;
 
 import java.io.IOException;
+import java.util.Arrays;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HRegionInfo;
@@ -31,15 +33,13 @@ import org.apache.hadoop.hbase.RegionLocations;
 import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
-import org.apache.hadoop.hbase.client.HTable;
-import org.apache.hadoop.hbase.client.HTableInterface;
 import org.apache.hadoop.hbase.client.Put;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.master.RegionState.State;
 import org.apache.hadoop.hbase.regionserver.HRegion;
 import org.apache.hadoop.hbase.regionserver.RegionServerServices;
 import org.apache.hadoop.hbase.util.Bytes;
-
+import org.apache.hadoop.hbase.util.MultiHConnection;
 import com.google.common.base.Preconditions;
 
 /**
@@ -54,9 +54,8 @@ public class RegionStateStore {
   protected static final char META_REPLICA_ID_DELIMITER = '_';
 
   private volatile HRegion metaRegion;
-  private volatile HTableInterface metaTable;
   private volatile boolean initialized;
-
+  private MultiHConnection multiHConnection;
   private final Server server;
 
   /**
@@ -132,33 +131,31 @@ public class RegionStateStore {
     initialized = false;
   }
 
-  @SuppressWarnings("deprecation")
   void start() throws IOException {
     if (server instanceof RegionServerServices) {
       metaRegion = ((RegionServerServices)server).getFromOnlineRegions(
         HRegionInfo.FIRST_META_REGIONINFO.getEncodedName());
     }
+    // When meta is not colocated on master
     if (metaRegion == null) {
-      metaTable = new HTable(TableName.META_TABLE_NAME,
-        server.getShortCircuitConnection());
+      Configuration conf = server.getConfiguration();
+      // Config to determine the no of HConnections to META.
+      // A single HConnection should be sufficient in most cases. Only if
+      // you are doing lot of writes (>1M) to META,
+      // increasing this value might improve the write throughput.
+      multiHConnection =
+          new MultiHConnection(conf, conf.getInt("hbase.regionstatestore.meta.connection", 1));
     }
     initialized = true;
   }
 
   void stop() {
     initialized = false;
-    if (metaTable != null) {
-      try {
-        metaTable.close();
-      } catch (IOException e) {
-        LOG.info("Got exception in closing meta table", e);
-      } finally {
-        metaTable = null;
-      }
+    if (multiHConnection != null) {
+      multiHConnection.close();
     }
   }
 
-  @SuppressWarnings("deprecation")
   void updateRegionState(long openSeqNum,
       RegionState newState, RegionState oldState) {
     if (!initialized) {
@@ -210,22 +207,23 @@ public class RegionStateStore {
           synchronized (this) {
             if (metaRegion != null) {
               LOG.info("Meta region shortcut failed", t);
-              metaTable = new HTable(TableName.META_TABLE_NAME,
-                server.getShortCircuitConnection());
+              if (multiHConnection == null) {
+                multiHConnection = new MultiHConnection(server.getConfiguration(), 1);
+              }
               metaRegion = null;
             }
           }
         }
       }
-      synchronized(metaTable) {
-        metaTable.put(put);
-      }
+      // Called when meta is not on master
+      multiHConnection.processBatchCallback(Arrays.asList(put), TableName.META_TABLE_NAME, null, null);
+        
     } catch (IOException ioe) {
       LOG.error("Failed to persist region state " + newState, ioe);
       server.abort("Failed to update region location", ioe);
     }
   }
-
+  
   void splitRegion(HRegionInfo p,
       HRegionInfo a, HRegionInfo b, ServerName sn) throws IOException {
     MetaTableAccessor.splitRegion(server.getShortCircuitConnection(), p, a, b, sn);

hbase-server/src/main/java/org/apache/hadoop/hbase/util/MultiHConnection.java

@@ -0,0 +1,156 @@
+/**
+ *
+ * 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.util;
+
+import java.io.IOException;
+import java.io.InterruptedIOException;
+import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.HConnection;
+import org.apache.hadoop.hbase.client.HConnectionManager;
+import org.apache.hadoop.hbase.client.Row;
+import org.apache.hadoop.hbase.client.coprocessor.Batch;
+
+/**
+ * Provides ability to create multiple HConnection instances and allows to process a batch of
+ * actions using HConnection.processBatchCallback()
+ */
+@InterfaceAudience.Private
+public class MultiHConnection {
+  private static final Log LOG = LogFactory.getLog(MultiHConnection.class);
+  private HConnection[] hConnections;
+  private int noOfConnections;
+  private ExecutorService batchPool;
+
+  /**
+   * Create multiple HConnection instances and initialize a thread pool executor
+   * @param conf configuration
+   * @param noOfConnections total no of HConnections to create
+   * @throws IOException
+   */
+  public MultiHConnection(Configuration conf, int noOfConnections)
+      throws IOException {
+    this.noOfConnections = noOfConnections;
+    hConnections = new HConnection[noOfConnections];
+    for (int i = 0; i < noOfConnections; i++) {
+      HConnection conn = HConnectionManager.createConnection(conf);
+      hConnections[i] = conn;
+    }
+    createBatchPool(conf);
+  }
+
+  /**
+   * Close the open connections and shutdown the batchpool
+   */
+  public void close() {
+    if (hConnections != null) {
+      synchronized (hConnections) {
+        if (hConnections != null) {
+          for (HConnection conn : hConnections) {
+            if (conn != null) {
+              try {
+                conn.close();
+              } catch (IOException e) {
+                LOG.info("Got exception in closing connection", e);
+              } finally {
+                conn = null;
+              }
+            }
+          }
+          hConnections = null;
+        }
+      }
+    }
+    if (this.batchPool != null && !this.batchPool.isShutdown()) {
+      this.batchPool.shutdown();
+      try {
+        if (!this.batchPool.awaitTermination(10, TimeUnit.SECONDS)) {
+          this.batchPool.shutdownNow();
+        }
+      } catch (InterruptedException e) {
+        this.batchPool.shutdownNow();
+      }
+    }
+
+  }
+
+  /**
+   * Randomly pick a connection and process the batch of actions for a given table
+   * @param actions the actions
+   * @param tableName table name
+   * @param results the results array
+   * @param callback 
+   * @throws IOException
+   * @throws InterruptedException
+   */
+  @SuppressWarnings("deprecation")
+  public <R> void processBatchCallback(List<? extends Row> actions, TableName tableName,
+      Object[] results, Batch.Callback<R> callback) throws IOException {
+    // Currently used by RegionStateStore
+    // A deprecated method is used as multiple threads accessing RegionStateStore do a single put
+    // and htable is not thread safe. Alternative would be to create an Htable instance for each 
+    // put but that is not very efficient.
+    // See HBASE-11610 for more details.
+    try {
+      hConnections[ThreadLocalRandom.current().nextInt(noOfConnections)].processBatchCallback(
+        actions, tableName, this.batchPool, results, callback);
+    } catch (InterruptedException e) {
+      throw new InterruptedIOException(e.getMessage());
+    }
+  }
+
+  
+  // Copied from HConnectionImplementation.getBatchPool()
+  // We should get rid of this when HConnection.processBatchCallback is un-deprecated and provides
+  // an API to manage a batch pool
+  private void createBatchPool(Configuration conf) {
+    // Use the same config for keep alive as in HConnectionImplementation.getBatchPool();
+    int maxThreads = conf.getInt("hbase.multihconnection.threads.max", 256);
+    int coreThreads = conf.getInt("hbase.multihconnection.threads.core", 256);
+    if (maxThreads == 0) {
+      maxThreads = Runtime.getRuntime().availableProcessors() * 8;
+    }
+    if (coreThreads == 0) {
+      coreThreads = Runtime.getRuntime().availableProcessors() * 8;
+    }
+    long keepAliveTime = conf.getLong("hbase.multihconnection.threads.keepalivetime", 60);
+    LinkedBlockingQueue<Runnable> workQueue =
+        new LinkedBlockingQueue<Runnable>(maxThreads
+            * conf.getInt(HConstants.HBASE_CLIENT_MAX_TOTAL_TASKS,
+              HConstants.DEFAULT_HBASE_CLIENT_MAX_TOTAL_TASKS));
+    ThreadPoolExecutor tpe =
+        new ThreadPoolExecutor(coreThreads, maxThreads, keepAliveTime, TimeUnit.SECONDS, workQueue,
+            Threads.newDaemonThreadFactory("MultiHConnection" + "-shared-"));
+    tpe.allowCoreThreadTimeOut(true);
+    this.batchPool = tpe;
+  }
+  
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestAssignmentManagerOnCluster.java

@@ -51,6 +51,8 @@ import org.apache.hadoop.hbase.UnknownRegionException;
 import org.apache.hadoop.hbase.Waiter;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.HTable;
+import org.apache.hadoop.hbase.client.Result;
+import org.apache.hadoop.hbase.coordination.ZkCoordinatedStateManager;
 import org.apache.hadoop.hbase.coprocessor.BaseRegionObserver;
 import org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
 import org.apache.hadoop.hbase.coprocessor.ObserverContext;
@@ -1050,7 +1052,63 @@ public class TestAssignmentManagerOnCluster {
       TEST_UTIL.deleteTable(Bytes.toBytes(table));
     }
   }
-
+  
+  /**
+   * Test concurrent updates to meta when meta is not on master
+   * @throws Exception
+   */
+  @Test(timeout = 30000)
+  public void testUpdatesRemoteMeta() throws Exception {
+    conf.setInt("hbase.regionstatestore.meta.connection", 3);
+    final RegionStateStore rss =
+        new RegionStateStore(new MyRegionServer(conf, new ZkCoordinatedStateManager()));
+    rss.start();
+    // Create 10 threads and make each do 10 puts related to region state update
+    Thread[] th = new Thread[10];
+    List<String> nameList = new ArrayList<String>();
+    List<TableName> tableNameList = new ArrayList<TableName>();
+    for (int i = 0; i < th.length; i++) {
+      th[i] = new Thread() {
+        @Override
+        public void run() {
+          HRegionInfo[] hri = new HRegionInfo[10];
+          ServerName serverName = ServerName.valueOf("dummyhost", 1000, 1234);
+          for (int i = 0; i < 10; i++) {
+            hri[i] = new HRegionInfo(TableName.valueOf(Thread.currentThread().getName() + "_" + i));
+            RegionState newState = new RegionState(hri[i], RegionState.State.OPEN, serverName);
+            RegionState oldState =
+                new RegionState(hri[i], RegionState.State.PENDING_OPEN, serverName);
+            rss.updateRegionState(1, newState, oldState);
+          }
+        }
+      };
+      th[i].start();
+      nameList.add(th[i].getName());
+    }
+    for (int i = 0; i < th.length; i++) {
+      th[i].join();
+    }
+    // Add all the expected table names in meta to tableNameList
+    for (String name : nameList) {
+      for (int i = 0; i < 10; i++) {
+        tableNameList.add(TableName.valueOf(name + "_" + i));
+      }
+    }
+    List<Result> metaRows = MetaTableAccessor.fullScanOfMeta(admin.getConnection());
+    int count = 0;
+    // Check all 100 rows are in meta
+    for (Result result : metaRows) {
+      if (tableNameList.contains(HRegionInfo.getTable(result.getRow()))) {
+        count++;
+        if (count == 100) {
+          break;
+        }
+      }
+    }
+    assertTrue(count == 100);
+    rss.stop();
+  }
+  
   static class MyLoadBalancer extends StochasticLoadBalancer {
     // For this region, if specified, always assign to nowhere
     static volatile String controledRegion = null;