HBASE-8131 - Create table handler needs to handle failure cases. (Ram)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1458922 13f79535-47bb-0310-9956-ffa450edef68

hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKTable.java

@@ -343,6 +343,23 @@ public class ZKTable {
       ZooKeeperProtos.Table.State.DISABLING);
   }
   
+  /**
+   * If the table is found in ENABLING state the inmemory state is removed. This
+   * helps in cases where CreateTable is to be retried by the client incase of
+   * failures
+   * 
+   * @param tableName
+   */
+  public void removeEnablingTable(final String tableName) {
+    synchronized (this.cache) {
+      if (isEnablingTable(tableName)) {
+        this.cache.remove(tableName);
+      }
+
+    }
+  }
+
+
   /**
    * Gets a list of all the tables of specified states in zookeeper.
    * @return Set of tables of specified states, empty Set if none

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

@@ -166,6 +166,15 @@ public class CreateTableHandler extends EventHandler {
    * @param exception null if process() is successful or not null if something has failed.
    */
   protected void completed(final Throwable exception) {
+    releaseTableLock();
+    if (exception != null) {
+      // Try deleting the enabling node in case of error
+      // If this does not happen then if the client tries to create the table
+      // again with the same Active master
+      // It will block the creation saying TableAlreadyExists.
+      this.assignmentManager.getZKTable().removeEnablingTable(
+          this.hTableDescriptor.getNameAsString());
+    }
   }
 
   /**
@@ -222,8 +231,6 @@ public class CreateTableHandler extends EventHandler {
     } catch (KeeperException e) {
       throw new IOException("Unable to ensure that " + tableName + " will be" +
         " enabled because of a ZooKeeper issue", e);
-    } finally {
-      releaseTableLock();
     }
   }
 

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

@@ -126,6 +126,7 @@ public class CloneSnapshotHandler extends CreateTableHandler implements Snapshot
   @Override
   protected void completed(final Throwable exception) {
     this.stopped = true;
+    super.completed(exception);
   }
 
   @Override

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

@@ -0,0 +1,110 @@
+/**
+ *
+ * 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.master.handler;
+
+import static org.junit.Assert.assertTrue;
+
+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.fs.Path;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.HColumnDescriptor;
+import org.apache.hadoop.hbase.HRegionInfo;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.MediumTests;
+import org.apache.hadoop.hbase.MiniHBaseCluster;
+import org.apache.hadoop.hbase.Server;
+import org.apache.hadoop.hbase.master.HMaster;
+import org.apache.hadoop.hbase.master.MasterFileSystem;
+import org.apache.hadoop.hbase.master.MasterServices;
+import org.apache.hadoop.hbase.master.TestMaster;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.zookeeper.ZKTable;
+import org.apache.hadoop.hbase.zookeeper.ZKUtil;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category(MediumTests.class)
+public class TestCreateTableHandler {
+  private static final HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
+  private static final Log LOG = LogFactory.getLog(TestCreateTableHandler.class);
+  private static final byte[] TABLENAME = Bytes.toBytes("TestCreateTableHandler");
+  private static final byte[] FAMILYNAME = Bytes.toBytes("fam");
+  public static boolean throwException = false;
+
+  @BeforeClass
+  public static void setUp() throws Exception {
+    TEST_UTIL.startMiniCluster(1);
+  }
+
+  @AfterClass
+  public static void tearDown() throws Exception {
+    TEST_UTIL.shutdownMiniCluster();
+  }
+
+  @Test
+  public void testCreateTableHandlerIfCalledTwoTimesAndFirstOneIsUnderProgress() throws Exception {
+    final MiniHBaseCluster cluster = TEST_UTIL.getHBaseCluster();
+    final HMaster m = cluster.getMaster();
+    final HTableDescriptor desc = new HTableDescriptor(TABLENAME);
+    desc.addFamily(new HColumnDescriptor(FAMILYNAME));
+    final HRegionInfo[] hRegionInfos = new HRegionInfo[] { new HRegionInfo(desc.getName(), null,
+        null) };
+    CustomCreateTableHandler handler = new CustomCreateTableHandler(m, m.getMasterFileSystem(),
+        desc, cluster.getConfiguration(), hRegionInfos, m);
+    handler.prepare();
+    throwException = true;
+    handler.process();
+    throwException = false;
+    CustomCreateTableHandler handler1 = new CustomCreateTableHandler(m, m.getMasterFileSystem(),
+        desc, cluster.getConfiguration(), hRegionInfos, m);
+    handler1.prepare();
+    handler1.process();
+    for (int i = 0; i < 100; i++) {
+      if (!TEST_UTIL.getHBaseAdmin().isTableAvailable(TABLENAME)) {
+        Thread.sleep(200);
+      }
+    }
+    assertTrue(TEST_UTIL.getHBaseAdmin().isTableEnabled(TABLENAME));
+
+  }
+
+  private static class CustomCreateTableHandler extends CreateTableHandler {
+    public CustomCreateTableHandler(Server server, MasterFileSystem fileSystemManager,
+        HTableDescriptor hTableDescriptor, Configuration conf, HRegionInfo[] newRegions,
+        MasterServices masterServices) {
+      super(server, fileSystemManager, hTableDescriptor, conf, newRegions, masterServices);
+    }
+
+    @Override
+    protected List<HRegionInfo> handleCreateHdfsRegions(Path tableRootDir, String tableName)
+        throws IOException {
+      if (throwException) {
+        throw new IOException("Test throws exceptions.");
+      }
+      return super.handleCreateHdfsRegions(tableRootDir, tableName);
+    }
+  }
+}