/*
    *
    * 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.coprocessor;
  
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertTrue;
  import static org.junit.Assert.fail;
  
  import java.io.IOException;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.client.Durability;
  import org.apache.hadoop.hbase.client.HTable;
  import org.apache.hadoop.hbase.client.Put;
  import org.apache.hadoop.hbase.regionserver.HRegionServer;
  import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
  import org.apache.hadoop.hbase.testclassification.MediumTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.junit.AfterClass;
  import org.junit.BeforeClass;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  /**
   * Tests unhandled exceptions thrown by coprocessors running on regionserver.
   * Expected result is that the region server will remove the buggy coprocessor from
   * its set of coprocessors and throw a org.apache.hadoop.hbase.exceptions.DoNotRetryIOException
   * back to the client.
   * (HBASE-4014).
   */
  @Category(MediumTests.class)
  public class TestRegionServerCoprocessorExceptionWithRemove {
    public static class BuggyRegionObserver extends SimpleRegionObserver {
      @Override
      @SuppressWarnings("null")
      @edu.umd.cs.findbugs.annotations.SuppressWarnings(value="NP_NULL_ON_SOME_PATH",
        justification="Preconditions checks insure we are not going to dereference a null value")
      public void prePut(final ObserverContext<RegionCoprocessorEnvironment> c,
                         final Put put, final WALEdit edit,
                         final Durability durability) {
        String tableName =
            c.getEnvironment().getRegion().getRegionInfo().getTable().getNameAsString();
        if (tableName.equals("observed_table")) {
          // Trigger a NPE to fail the coprocessor
          Integer i = null;
          i = i + 1;
        }
      }
    }
  
    private static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
  
    @BeforeClass
    public static void setupBeforeClass() throws Exception {
      // set configure to indicate which cp should be loaded
      Configuration conf = TEST_UTIL.getConfiguration();
      conf.set(CoprocessorHost.REGION_COPROCESSOR_CONF_KEY,
          BuggyRegionObserver.class.getName());
      TEST_UTIL.getConfiguration().setBoolean(CoprocessorHost.ABORT_ON_ERROR_KEY, false);
      TEST_UTIL.startMiniCluster();
    }
  
    @AfterClass
    public static void teardownAfterClass() throws Exception {
      TEST_UTIL.shutdownMiniCluster();
    }
  
    @Test(timeout=60000)
    public void testExceptionFromCoprocessorDuringPut()
        throws IOException, InterruptedException {
      // Set watches on the zookeeper nodes for all of the regionservers in the
      // cluster. When we try to write to TEST_TABLE, the buggy coprocessor will
      // cause a NullPointerException, which will cause the regionserver (which
      // hosts the region we attempted to write to) to abort. In turn, this will
      // cause the nodeDeleted() method of the DeadRegionServer tracker to
      // execute, which will set the rsZKNodeDeleted flag to true, which will
      // pass this test.
  
      TableName TEST_TABLE = TableName.valueOf("observed_table");
      byte[] TEST_FAMILY = Bytes.toBytes("aaa");
 
     HTable table = TEST_UTIL.createMultiRegionTable(TEST_TABLE, TEST_FAMILY);
     TEST_UTIL.waitUntilAllRegionsAssigned(TEST_TABLE);
     // Note which regionServer that should survive the buggy coprocessor's
     // prePut().
     HRegionServer regionServer =
         TEST_UTIL.getRSForFirstRegionInTable(TEST_TABLE);
 
     boolean threwIOE = false;
     try {
       final byte[] ROW = Bytes.toBytes("aaa");
       Put put = new Put(ROW);
       put.add(TEST_FAMILY, ROW, ROW);
       table.put(put);
       table.flushCommits();
       // We may need two puts to reliably get an exception
       table.put(put);
       table.flushCommits();
     } catch (IOException e) {
       threwIOE = true;
     } finally {
       assertTrue("The regionserver should have thrown an exception", threwIOE);
     }
 
     // Wait 10 seconds for the regionserver to abort: expected result is that
     // it will survive and not abort.
     for (int i = 0; i < 10; i++) {
       assertFalse(regionServer.isAborted());
       try {
         Thread.sleep(1000);
       } catch (InterruptedException e) {
         fail("InterruptedException while waiting for regionserver " +
             "zk node to be deleted.");
       }
     }
     table.close();
   }
 
 }