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.procedure;
019
020import static org.mockito.Matchers.any;
021import static org.mockito.Matchers.anyString;
022import static org.mockito.Mockito.mock;
023import static org.mockito.Mockito.never;
024import static org.mockito.Mockito.spy;
025import static org.mockito.Mockito.verify;
026import static org.mockito.Mockito.when;
027
028import java.util.ArrayList;
029import java.util.List;
030import java.util.concurrent.CountDownLatch;
031import org.apache.hadoop.hbase.HBaseClassTestRule;
032import org.apache.hadoop.hbase.errorhandling.ForeignException;
033import org.apache.hadoop.hbase.errorhandling.ForeignExceptionDispatcher;
034import org.apache.hadoop.hbase.testclassification.MasterTests;
035import org.apache.hadoop.hbase.testclassification.SmallTests;
036import org.junit.Before;
037import org.junit.ClassRule;
038import org.junit.Test;
039import org.junit.experimental.categories.Category;
040
041/**
042 * Demonstrate how Procedure handles single members, multiple members, and errors semantics
043 */
044@Category({ MasterTests.class, SmallTests.class })
045public class TestProcedure {
046
047  @ClassRule
048  public static final HBaseClassTestRule CLASS_RULE =
049    HBaseClassTestRule.forClass(TestProcedure.class);
050
051  ProcedureCoordinator coord;
052
053  @Before
054  public void setup() {
055    coord = mock(ProcedureCoordinator.class);
056    final ProcedureCoordinatorRpcs comms = mock(ProcedureCoordinatorRpcs.class);
057    when(coord.getRpcs()).thenReturn(comms); // make it not null
058  }
059
060  static class LatchedProcedure extends Procedure {
061    CountDownLatch startedAcquireBarrier = new CountDownLatch(1);
062    CountDownLatch startedDuringBarrier = new CountDownLatch(1);
063    CountDownLatch completedProcedure = new CountDownLatch(1);
064
065    public LatchedProcedure(ProcedureCoordinator coord, ForeignExceptionDispatcher monitor,
066      long wakeFreq, long timeout, String opName, byte[] data, List<String> expectedMembers) {
067      super(coord, monitor, wakeFreq, timeout, opName, data, expectedMembers);
068    }
069
070    @Override
071    public void sendGlobalBarrierStart() {
072      startedAcquireBarrier.countDown();
073    }
074
075    @Override
076    public void sendGlobalBarrierReached() {
077      startedDuringBarrier.countDown();
078    }
079
080    @Override
081    public void sendGlobalBarrierComplete() {
082      completedProcedure.countDown();
083    }
084  }
085
086  /**
087   * With a single member, verify ordered execution. The Coordinator side is run in a separate
088   * thread so we can only trigger from members and wait for particular state latches.
089   */
090  @Test
091  public void testSingleMember() throws Exception {
092    // The member
093    List<String> members = new ArrayList<>();
094    members.add("member");
095    LatchedProcedure proc = new LatchedProcedure(coord, new ForeignExceptionDispatcher(), 100,
096      Integer.MAX_VALUE, "op", null, members);
097    final LatchedProcedure procspy = spy(proc);
098    // coordinator: start the barrier procedure
099    new Thread() {
100      @Override
101      public void run() {
102        procspy.call();
103      }
104    }.start();
105
106    // coordinator: wait for the barrier to be acquired, then send start barrier
107    proc.startedAcquireBarrier.await();
108
109    // we only know that {@link Procedure#sendStartBarrier()} was called, and others are blocked.
110    verify(procspy).sendGlobalBarrierStart();
111    verify(procspy, never()).sendGlobalBarrierReached();
112    verify(procspy, never()).sendGlobalBarrierComplete();
113    verify(procspy, never()).barrierAcquiredByMember(anyString());
114
115    // member: trigger global barrier acquisition
116    proc.barrierAcquiredByMember(members.get(0));
117
118    // coordinator: wait for global barrier to be acquired.
119    proc.acquiredBarrierLatch.await();
120    verify(procspy).sendGlobalBarrierStart(); // old news
121
122    // since two threads, we cannot guarantee that {@link Procedure#sendSatsifiedBarrier()} was
123    // or was not called here.
124
125    // member: trigger global barrier release
126    proc.barrierReleasedByMember(members.get(0), new byte[0]);
127
128    // coordinator: wait for procedure to be completed
129    proc.completedProcedure.await();
130    verify(procspy).sendGlobalBarrierReached();
131    verify(procspy).sendGlobalBarrierComplete();
132    verify(procspy, never()).receive(any());
133  }
134
135  @Test
136  public void testMultipleMember() throws Exception {
137    // 2 members
138    List<String> members = new ArrayList<>();
139    members.add("member1");
140    members.add("member2");
141
142    LatchedProcedure proc = new LatchedProcedure(coord, new ForeignExceptionDispatcher(), 100,
143      Integer.MAX_VALUE, "op", null, members);
144    final LatchedProcedure procspy = spy(proc);
145    // start the barrier procedure
146    new Thread() {
147      @Override
148      public void run() {
149        procspy.call();
150      }
151    }.start();
152
153    // coordinator: wait for the barrier to be acquired, then send start barrier
154    procspy.startedAcquireBarrier.await();
155
156    // we only know that {@link Procedure#sendStartBarrier()} was called, and others are blocked.
157    verify(procspy).sendGlobalBarrierStart();
158    verify(procspy, never()).sendGlobalBarrierReached();
159    verify(procspy, never()).sendGlobalBarrierComplete();
160    verify(procspy, never()).barrierAcquiredByMember(anyString()); // no externals
161
162    // member0: [1/2] trigger global barrier acquisition.
163    procspy.barrierAcquiredByMember(members.get(0));
164
165    // coordinator not satisified.
166    verify(procspy).sendGlobalBarrierStart();
167    verify(procspy, never()).sendGlobalBarrierReached();
168    verify(procspy, never()).sendGlobalBarrierComplete();
169
170    // member 1: [2/2] trigger global barrier acquisition.
171    procspy.barrierAcquiredByMember(members.get(1));
172
173    // coordinator: wait for global barrier to be acquired.
174    procspy.startedDuringBarrier.await();
175    verify(procspy).sendGlobalBarrierStart(); // old news
176
177    // member 1, 2: trigger global barrier release
178    procspy.barrierReleasedByMember(members.get(0), new byte[0]);
179    procspy.barrierReleasedByMember(members.get(1), new byte[0]);
180
181    // coordinator wait for procedure to be completed
182    procspy.completedProcedure.await();
183    verify(procspy).sendGlobalBarrierReached();
184    verify(procspy).sendGlobalBarrierComplete();
185    verify(procspy, never()).receive(any());
186  }
187
188  @Test
189  public void testErrorPropagation() throws Exception {
190    List<String> members = new ArrayList<>();
191    members.add("member");
192    Procedure proc = new Procedure(coord, new ForeignExceptionDispatcher(), 100, Integer.MAX_VALUE,
193      "op", null, members);
194    final Procedure procspy = spy(proc);
195
196    ForeignException cause = new ForeignException("SRC", "External Exception");
197    proc.receive(cause);
198
199    // start the barrier procedure
200    Thread t = new Thread() {
201      @Override
202      public void run() {
203        procspy.call();
204      }
205    };
206    t.start();
207    t.join();
208
209    verify(procspy, never()).sendGlobalBarrierStart();
210    verify(procspy, never()).sendGlobalBarrierReached();
211    verify(procspy).sendGlobalBarrierComplete();
212  }
213
214  @Test
215  public void testBarrieredErrorPropagation() throws Exception {
216    List<String> members = new ArrayList<>();
217    members.add("member");
218    LatchedProcedure proc = new LatchedProcedure(coord, new ForeignExceptionDispatcher(), 100,
219      Integer.MAX_VALUE, "op", null, members);
220    final LatchedProcedure procspy = spy(proc);
221
222    // start the barrier procedure
223    Thread t = new Thread() {
224      @Override
225      public void run() {
226        procspy.call();
227      }
228    };
229    t.start();
230
231    // now test that we can put an error in before the commit phase runs
232    procspy.startedAcquireBarrier.await();
233    ForeignException cause = new ForeignException("SRC", "External Exception");
234    procspy.receive(cause);
235    procspy.barrierAcquiredByMember(members.get(0));
236    t.join();
237
238    // verify state of all the object
239    verify(procspy).sendGlobalBarrierStart();
240    verify(procspy).sendGlobalBarrierComplete();
241    verify(procspy, never()).sendGlobalBarrierReached();
242  }
243}