001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.errorhandling;
019
020import static org.junit.Assert.assertTrue;
021import static org.junit.Assert.fail;
022
023import org.apache.hadoop.hbase.HBaseClassTestRule;
024import org.apache.hadoop.hbase.testclassification.MasterTests;
025import org.apache.hadoop.hbase.testclassification.SmallTests;
026import org.junit.ClassRule;
027import org.junit.Test;
028import org.junit.experimental.categories.Category;
029import org.mockito.Mockito;
030import org.slf4j.Logger;
031import org.slf4j.LoggerFactory;
032
033/**
034 * Test that we propagate errors through an dispatcher exactly once via different failure
035 * injection mechanisms.
036 */
037@Category({MasterTests.class, SmallTests.class})
038public class TestForeignExceptionDispatcher {
039
040  @ClassRule
041  public static final HBaseClassTestRule CLASS_RULE =
042      HBaseClassTestRule.forClass(TestForeignExceptionDispatcher.class);
043
044  private static final Logger LOG = LoggerFactory.getLogger(TestForeignExceptionDispatcher.class);
045
046  /**
047   * Exception thrown from the test
048   */
049  final ForeignException EXTEXN = new ForeignException("FORTEST", new IllegalArgumentException("FORTEST"));
050  final ForeignException EXTEXN2 = new ForeignException("FORTEST2", new IllegalArgumentException("FORTEST2"));
051
052  /**
053   * Tests that a dispatcher only dispatches only the first exception, and does not propagate
054   * subsequent exceptions.
055   */
056  @Test
057  public void testErrorPropagation() {
058    ForeignExceptionListener listener1 = Mockito.mock(ForeignExceptionListener.class);
059    ForeignExceptionListener listener2 = Mockito.mock(ForeignExceptionListener.class);
060    ForeignExceptionDispatcher dispatcher = new ForeignExceptionDispatcher();
061
062    // add the listeners
063    dispatcher.addListener(listener1);
064    dispatcher.addListener(listener2);
065
066    // create an artificial error
067    dispatcher.receive(EXTEXN);
068
069    // make sure the listeners got the error
070    Mockito.verify(listener1, Mockito.times(1)).receive(EXTEXN);
071    Mockito.verify(listener2, Mockito.times(1)).receive(EXTEXN);
072
073    // make sure that we get an exception
074    try {
075      dispatcher.rethrowException();
076      fail("Monitor should have thrown an exception after getting error.");
077    } catch (ForeignException ex) {
078      assertTrue("Got an unexpected exception:" + ex, ex.getCause() == EXTEXN.getCause());
079      LOG.debug("Got the testing exception!");
080    }
081
082    // push another error, which should be not be passed to listeners
083    dispatcher.receive(EXTEXN2);
084    Mockito.verify(listener1, Mockito.never()).receive(EXTEXN2);
085    Mockito.verify(listener2, Mockito.never()).receive(EXTEXN2);
086  }
087
088  @Test
089  public void testSingleDispatcherWithTimer() {
090    ForeignExceptionListener listener1 = Mockito.mock(ForeignExceptionListener.class);
091    ForeignExceptionListener listener2 = Mockito.mock(ForeignExceptionListener.class);
092
093    ForeignExceptionDispatcher monitor = new ForeignExceptionDispatcher();
094
095    // add the listeners
096    monitor.addListener(listener1);
097    monitor.addListener(listener2);
098
099    TimeoutExceptionInjector timer = new TimeoutExceptionInjector(monitor, 1000);
100    timer.start();
101    timer.trigger();
102
103    assertTrue("Monitor didn't get timeout", monitor.hasException());
104
105    // verify that that we propagated the error
106    Mockito.verify(listener1).receive(Mockito.any());
107    Mockito.verify(listener2).receive(Mockito.any());
108  }
109
110  /**
111   * Test that the dispatcher can receive an error via the timer mechanism.
112   */
113  @Test
114  public void testAttemptTimer() {
115    ForeignExceptionListener listener1 = Mockito.mock(ForeignExceptionListener.class);
116    ForeignExceptionListener listener2 = Mockito.mock(ForeignExceptionListener.class);
117    ForeignExceptionDispatcher orchestrator = new ForeignExceptionDispatcher();
118
119    // add the listeners
120    orchestrator.addListener(listener1);
121    orchestrator.addListener(listener2);
122
123    // now create a timer and check for that error
124    TimeoutExceptionInjector timer = new TimeoutExceptionInjector(orchestrator, 1000);
125    timer.start();
126    timer.trigger();
127    // make sure that we got the timer error
128    Mockito.verify(listener1, Mockito.times(1)).receive(Mockito.any());
129    Mockito.verify(listener2, Mockito.times(1)).receive(Mockito.any());
130  }
131}