HBASE-12966 NPE in HMaster while recovering tables in Enabling state (Andrey Stepachev)

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

@@ -26,14 +26,14 @@ import java.util.Map;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.apache.hadoop.hbase.classification.InterfaceAudience;
-import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.HRegionInfo;
+import org.apache.hadoop.hbase.MetaTableAccessor;
 import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.TableNotDisabledException;
 import org.apache.hadoop.hbase.TableNotFoundException;
-import org.apache.hadoop.hbase.MetaTableAccessor;
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.client.TableState;
 import org.apache.hadoop.hbase.executor.EventHandler;
 import org.apache.hadoop.hbase.executor.EventType;
@@ -207,10 +207,12 @@ public class EnableTableHandler extends EventHandler {
     List<ServerName> onlineServers = serverManager.createDestinationServersList();
     Map<ServerName, List<HRegionInfo>> bulkPlan =
         this.assignmentManager.getBalancer().retainAssignment(regionsToAssign, onlineServers);
+    if (bulkPlan != null) {
       LOG.info("Bulk assigning " + regionsCount + " region(s) across " + bulkPlan.size()
           + " server(s), retainAssignment=true");
 
-    BulkAssigner ba = new GeneralBulkAssigner(this.server, bulkPlan, this.assignmentManager, true);
+      BulkAssigner ba =
+          new GeneralBulkAssigner(this.server, bulkPlan, this.assignmentManager, true);
       try {
         if (ba.bulkAssign()) {
           done = true;
@@ -221,6 +223,11 @@ public class EnableTableHandler extends EventHandler {
         // Preserve the interrupt.
         Thread.currentThread().interrupt();
       }
+    } else {
+      LOG.info("Balancer was unable to find suitable servers for table " + tableName
+          + ", leaving unassigned");
+      done = true;
+    }
     if (done) {
       // Flip the table to enabled.
       this.assignmentManager.getTableStateManager().setTableState(

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

@@ -0,0 +1,101 @@
+/**
+ *
+ * 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 java.util.List;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+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.MiniHBaseCluster;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.HBaseAdmin;
+import org.apache.hadoop.hbase.master.HMaster;
+import org.apache.hadoop.hbase.testclassification.MasterTests;
+import org.apache.hadoop.hbase.testclassification.MediumTests;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.JVMClusterUtil;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+@Category({ MasterTests.class, MediumTests.class })
+public class TestEnableTableHandler {
+  private static final HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
+  private static final Log LOG = LogFactory.getLog(TestEnableTableHandler.class);
+  private static final byte[] FAMILYNAME = Bytes.toBytes("fam");
+
+  @Before
+  public void setUp() throws Exception {
+    TEST_UTIL.startMiniCluster(1);
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    TEST_UTIL.shutdownMiniCluster();
+  }
+
+  @Test(timeout = 300000)
+  public void testEnableTableWithNoRegionServers() throws Exception {
+    final TableName tableName = TableName.valueOf("testEnableTableWithNoRegionServers");
+    final MiniHBaseCluster cluster = TEST_UTIL.getHBaseCluster();
+    final HMaster m = cluster.getMaster();
+    final HBaseAdmin admin = TEST_UTIL.getHBaseAdmin();
+    final HTableDescriptor desc = new HTableDescriptor(tableName);
+    desc.addFamily(new HColumnDescriptor(FAMILYNAME));
+    admin.createTable(desc);
+    admin.disableTable(tableName);
+    TEST_UTIL.waitTableDisabled(tableName.getName());
+
+    admin.enableTable(tableName);
+    TEST_UTIL.waitTableEnabled(tableName);
+
+    // disable once more
+    admin.disableTable(tableName);
+
+    // now stop region servers
+    JVMClusterUtil.RegionServerThread rs = cluster.getRegionServerThreads().get(0);
+    rs.getRegionServer().stop("stop");
+    cluster.waitForRegionServerToStop(rs.getRegionServer().getServerName(), 10000);
+
+    EnableTableHandler handler =
+        new EnableTableHandler(m, tableName, m.getAssignmentManager(), m.getTableLockManager(),
+            true);
+    handler.prepare();
+    handler.process();
+
+    assertTrue(admin.isTableEnabled(tableName));
+
+    JVMClusterUtil.RegionServerThread rs2 = cluster.startRegionServer();
+    m.getAssignmentManager().assign(admin.getTableRegions(tableName));
+    TEST_UTIL.waitUntilAllRegionsAssigned(tableName);
+    List<HRegionInfo> onlineRegions = admin.getOnlineRegions(
+        rs2.getRegionServer().getServerName());
+    assertEquals(1, onlineRegions.size());
+    assertEquals(tableName, onlineRegions.get(0).getTable());
+  }
+
+}