/**
* 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.ha;
import java.io.IOException;
import java.util.Collections;
import java.util.List;
import org.apache.zookeeper.AsyncCallback;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.KeeperException.Code;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.Watcher.Event;
import org.apache.zookeeper.data.ACL;
import org.apache.zookeeper.data.Stat;
import org.apache.zookeeper.ZooDefs.Ids;
import org.junit.Before;
import org.junit.Test;
import org.junit.Assert;
import org.mockito.Mockito;
import org.apache.hadoop.HadoopIllegalArgumentException;
import org.apache.hadoop.ha.ActiveStandbyElector.ActiveStandbyElectorCallback;
import org.apache.hadoop.ha.ActiveStandbyElector.ActiveNotFoundException;
import org.apache.hadoop.util.ZKUtil.ZKAuthInfo;
import org.apache.hadoop.test.GenericTestUtils;
public class TestActiveStandbyElector {
private ZooKeeper mockZK;
private int count;
private ActiveStandbyElectorCallback mockApp;
private final byte[] data = new byte[8];
private ActiveStandbyElectorTester elector;
class ActiveStandbyElectorTester extends ActiveStandbyElector {
private int sleptFor = 0;
ActiveStandbyElectorTester(String hostPort, int timeout, String parent,
List<ACL> acl, ActiveStandbyElectorCallback app) throws IOException,
KeeperException {
super(hostPort, timeout, parent, acl,
Collections.<ZKAuthInfo>emptyList(), app);
}
@Override
public ZooKeeper getNewZooKeeper() {
++count;
return mockZK;
}
@Override
protected void sleepFor(int ms) {
// don't sleep in unit tests! Instead, just record the amount of
// time slept
LOG.info("Would have slept for " + ms + "ms");
sleptFor += ms;
}
}
private static final String ZK_PARENT_NAME = "/parent/node";
private static final String ZK_LOCK_NAME = ZK_PARENT_NAME + "/" +
ActiveStandbyElector.LOCK_FILENAME;
private static final String ZK_BREADCRUMB_NAME = ZK_PARENT_NAME + "/" +
ActiveStandbyElector.BREADCRUMB_FILENAME;
@Before
public void init() throws IOException, KeeperException {
count = 0;
mockZK = Mockito.mock(ZooKeeper.class);
mockApp = Mockito.mock(ActiveStandbyElectorCallback.class);
elector = new ActiveStandbyElectorTester("hostPort", 1000, ZK_PARENT_NAME,
Ids.OPEN_ACL_UNSAFE, mockApp);
}
/**
* Set up the mock ZK to return no info for a prior active in ZK.
*/
private void mockNoPriorActive() throws Exception {
Mockito.doThrow(new KeeperException.NoNodeException()).when(mockZK)
.getData(Mockito.eq(ZK_BREADCRUMB_NAME), Mockito.anyBoolean(),
Mockito.<Stat>any());
}
/**
* Set up the mock to return info for some prior active node in ZK./
*/
private void mockPriorActive(byte[] data) throws Exception {
Mockito.doReturn(data).when(mockZK)
.getData(Mockito.eq(ZK_BREADCRUMB_NAME), Mockito.anyBoolean(),
Mockito.<Stat>any());
}
/**
* verify that joinElection checks for null data
*/
@Test(expected = HadoopIllegalArgumentException.class)
public void testJoinElectionException() {
elector.joinElection(null);
}
/**
* verify that joinElection tries to create ephemeral lock znode
*/
@Test
public void testJoinElection() {
elector.joinElection(data);
Mockito.verify(mockZK, Mockito.times(1)).create(ZK_LOCK_NAME, data,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
}
/**
* verify that successful znode create result becomes active and monitoring is
* started
*/
@Test
public void testCreateNodeResultBecomeActive() throws Exception {
mockNoPriorActive();
elector.joinElection(data);
elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
Mockito.verify(mockApp, Mockito.times(1)).becomeActive();
verifyExistCall(1);
// monitor callback verifies the leader is ephemeral owner of lock but does
// not call becomeActive since its already active
Stat stat = new Stat();
stat.setEphemeralOwner(1L);
Mockito.when(mockZK.getSessionId()).thenReturn(1L);
elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK, stat);
// should not call neutral mode/standby/active
Mockito.verify(mockApp, Mockito.times(0)).enterNeutralMode();
Mockito.verify(mockApp, Mockito.times(0)).becomeStandby();
Mockito.verify(mockApp, Mockito.times(1)).becomeActive();
// another joinElection not called.
Mockito.verify(mockZK, Mockito.times(1)).create(ZK_LOCK_NAME, data,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
// no new monitor called
verifyExistCall(1);
}
/**
* Verify that, when the callback fails to enter active state,
* the elector rejoins the election after sleeping for a short period.
*/
@Test
public void testFailToBecomeActive() throws Exception {
mockNoPriorActive();
elector.joinElection(data);
Assert.assertEquals(0, elector.sleptFor);
Mockito.doThrow(new ServiceFailedException("failed to become active"))
.when(mockApp).becomeActive();
elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
// Should have tried to become active
Mockito.verify(mockApp).becomeActive();
// should re-join
Mockito.verify(mockZK, Mockito.times(2)).create(ZK_LOCK_NAME, data,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
Assert.assertEquals(2, count);
Assert.assertTrue(elector.sleptFor > 0);
}
/**
* Verify that, when the callback fails to enter active state, after
* a ZK disconnect (i.e from the StatCallback), that the elector rejoins
* the election after sleeping for a short period.
*/
@Test
public void testFailToBecomeActiveAfterZKDisconnect() throws Exception {
mockNoPriorActive();
elector.joinElection(data);
Assert.assertEquals(0, elector.sleptFor);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
Mockito.verify(mockZK, Mockito.times(2)).create(ZK_LOCK_NAME, data,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
elector.processResult(Code.NODEEXISTS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
verifyExistCall(1);
Stat stat = new Stat();
stat.setEphemeralOwner(1L);
Mockito.when(mockZK.getSessionId()).thenReturn(1L);
// Fake failure to become active from within the stat callback
Mockito.doThrow(new ServiceFailedException("fail to become active"))
.when(mockApp).becomeActive();
elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK, stat);
Mockito.verify(mockApp, Mockito.times(1)).becomeActive();
// should re-join
Mockito.verify(mockZK, Mockito.times(3)).create(ZK_LOCK_NAME, data,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
Assert.assertEquals(2, count);
Assert.assertTrue(elector.sleptFor > 0);
}
/**
* Verify that, if there is a record of a prior active node, the
* elector asks the application to fence it before becoming active.
*/
@Test
public void testFencesOldActive() throws Exception {
byte[] fakeOldActiveData = new byte[0];
mockPriorActive(fakeOldActiveData);
elector.joinElection(data);
elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
// Application fences active.
Mockito.verify(mockApp, Mockito.times(1)).fenceOldActive(
fakeOldActiveData);
// Updates breadcrumb node to new data
Mockito.verify(mockZK, Mockito.times(1)).setData(
Mockito.eq(ZK_BREADCRUMB_NAME),
Mockito.eq(data),
Mockito.eq(0));
// Then it becomes active itself
Mockito.verify(mockApp, Mockito.times(1)).becomeActive();
}
@Test
public void testQuitElectionRemovesBreadcrumbNode() throws Exception {
mockNoPriorActive();
elector.joinElection(data);
elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
// Writes its own active info
Mockito.verify(mockZK, Mockito.times(1)).create(
Mockito.eq(ZK_BREADCRUMB_NAME), Mockito.eq(data),
Mockito.eq(Ids.OPEN_ACL_UNSAFE),
Mockito.eq(CreateMode.PERSISTENT));
mockPriorActive(data);
elector.quitElection(false);
// Deletes its own active data
Mockito.verify(mockZK, Mockito.times(1)).delete(
Mockito.eq(ZK_BREADCRUMB_NAME), Mockito.eq(0));
}
/**
* verify that znode create for existing node and no retry becomes standby and
* monitoring is started
*/
@Test
public void testCreateNodeResultBecomeStandby() {
elector.joinElection(data);
elector.processResult(Code.NODEEXISTS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
Mockito.verify(mockApp, Mockito.times(1)).becomeStandby();
verifyExistCall(1);
}
/**
* verify that znode create error result in fatal error
*/
@Test
public void testCreateNodeResultError() {
elector.joinElection(data);
elector.processResult(Code.APIERROR.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
Mockito.verify(mockApp, Mockito.times(1)).notifyFatalError(
"Received create error from Zookeeper. code:APIERROR " +
"for path " + ZK_LOCK_NAME);
}
/**
* verify that retry of network errors verifies master by session id and
* becomes active if they match. monitoring is started.
*/
@Test
public void testCreateNodeResultRetryBecomeActive() throws Exception {
mockNoPriorActive();
elector.joinElection(data);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
// 4 errors results in fatalError
Mockito
.verify(mockApp, Mockito.times(1))
.notifyFatalError(
"Received create error from Zookeeper. code:CONNECTIONLOSS " +
"for path " + ZK_LOCK_NAME + ". " +
"Not retrying further znode create connection errors.");
elector.joinElection(data);
// recreate connection via getNewZooKeeper
Assert.assertEquals(2, count);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
elector.processResult(Code.NODEEXISTS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
verifyExistCall(1);
Stat stat = new Stat();
stat.setEphemeralOwner(1L);
Mockito.when(mockZK.getSessionId()).thenReturn(1L);
elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK, stat);
Mockito.verify(mockApp, Mockito.times(1)).becomeActive();
verifyExistCall(1);
Mockito.verify(mockZK, Mockito.times(6)).create(ZK_LOCK_NAME, data,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
}
/**
* verify that retry of network errors verifies active by session id and
* becomes standby if they dont match. monitoring is started.
*/
@Test
public void testCreateNodeResultRetryBecomeStandby() {
elector.joinElection(data);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
elector.processResult(Code.NODEEXISTS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
verifyExistCall(1);
Stat stat = new Stat();
stat.setEphemeralOwner(0);
Mockito.when(mockZK.getSessionId()).thenReturn(1L);
elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK, stat);
Mockito.verify(mockApp, Mockito.times(1)).becomeStandby();
verifyExistCall(1);
}
/**
* verify that if create znode results in nodeexists and that znode is deleted
* before exists() watch is set then the return of the exists() method results
* in attempt to re-create the znode and become active
*/
@Test
public void testCreateNodeResultRetryNoNode() {
elector.joinElection(data);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
elector.processResult(Code.NODEEXISTS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
verifyExistCall(1);
elector.processResult(Code.NONODE.intValue(), ZK_LOCK_NAME, mockZK,
(Stat) null);
Mockito.verify(mockApp, Mockito.times(1)).enterNeutralMode();
Mockito.verify(mockZK, Mockito.times(4)).create(ZK_LOCK_NAME, data,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
}
/**
* verify that more than 3 network error retries result fatalError
*/
@Test
public void testStatNodeRetry() {
elector.joinElection(data);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
(Stat) null);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
(Stat) null);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
(Stat) null);
elector.processResult(Code.CONNECTIONLOSS.intValue(), ZK_LOCK_NAME, mockZK,
(Stat) null);
Mockito
.verify(mockApp, Mockito.times(1))
.notifyFatalError(
"Received stat error from Zookeeper. code:CONNECTIONLOSS. "+
"Not retrying further znode monitoring connection errors.");
}
/**
* verify error in exists() callback results in fatal error
*/
@Test
public void testStatNodeError() {
elector.joinElection(data);
elector.processResult(Code.RUNTIMEINCONSISTENCY.intValue(), ZK_LOCK_NAME,
mockZK, (Stat) null);
Mockito.verify(mockApp, Mockito.times(0)).enterNeutralMode();
Mockito.verify(mockApp, Mockito.times(1)).notifyFatalError(
"Received stat error from Zookeeper. code:RUNTIMEINCONSISTENCY");
}
/**
* verify behavior of watcher.process callback with non-node event
*/
@Test
public void testProcessCallbackEventNone() throws Exception {
mockNoPriorActive();
elector.joinElection(data);
WatchedEvent mockEvent = Mockito.mock(WatchedEvent.class);
Mockito.when(mockEvent.getType()).thenReturn(Event.EventType.None);
// first SyncConnected should not do anything
Mockito.when(mockEvent.getState()).thenReturn(
Event.KeeperState.SyncConnected);
elector.processWatchEvent(mockZK, mockEvent);
Mockito.verify(mockZK, Mockito.times(0)).exists(Mockito.anyString(),
Mockito.anyBoolean(), Mockito.<AsyncCallback.StatCallback> anyObject(),
Mockito.<Object> anyObject());
// disconnection should enter safe mode
Mockito.when(mockEvent.getState()).thenReturn(
Event.KeeperState.Disconnected);
elector.processWatchEvent(mockZK, mockEvent);
Mockito.verify(mockApp, Mockito.times(1)).enterNeutralMode();
// re-connection should monitor master status
Mockito.when(mockEvent.getState()).thenReturn(
Event.KeeperState.SyncConnected);
elector.processWatchEvent(mockZK, mockEvent);
verifyExistCall(1);
// session expired should enter safe mode and initiate re-election
// re-election checked via checking re-creation of new zookeeper and
// call to create lock znode
Mockito.when(mockEvent.getState()).thenReturn(Event.KeeperState.Expired);
elector.processWatchEvent(mockZK, mockEvent);
// already in safe mode above. should not enter safe mode again
Mockito.verify(mockApp, Mockito.times(1)).enterNeutralMode();
// called getNewZooKeeper to create new session. first call was in
// constructor
Assert.assertEquals(2, count);
// once in initial joinElection and one now
Mockito.verify(mockZK, Mockito.times(2)).create(ZK_LOCK_NAME, data,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
// create znode success. become master and monitor
elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
Mockito.verify(mockApp, Mockito.times(1)).becomeActive();
verifyExistCall(2);
// error event results in fatal error
Mockito.when(mockEvent.getState()).thenReturn(Event.KeeperState.AuthFailed);
elector.processWatchEvent(mockZK, mockEvent);
Mockito.verify(mockApp, Mockito.times(1)).notifyFatalError(
"Unexpected Zookeeper watch event state: AuthFailed");
// only 1 state change callback is called at a time
Mockito.verify(mockApp, Mockito.times(1)).enterNeutralMode();
}
/**
* verify behavior of watcher.process with node event
*/
@Test
public void testProcessCallbackEventNode() throws Exception {
mockNoPriorActive();
elector.joinElection(data);
// make the object go into the monitoring state
elector.processResult(Code.NODEEXISTS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
Mockito.verify(mockApp, Mockito.times(1)).becomeStandby();
verifyExistCall(1);
WatchedEvent mockEvent = Mockito.mock(WatchedEvent.class);
Mockito.when(mockEvent.getPath()).thenReturn(ZK_LOCK_NAME);
// monitoring should be setup again after event is received
Mockito.when(mockEvent.getType()).thenReturn(
Event.EventType.NodeDataChanged);
elector.processWatchEvent(mockZK, mockEvent);
verifyExistCall(2);
// monitoring should be setup again after event is received
Mockito.when(mockEvent.getType()).thenReturn(
Event.EventType.NodeChildrenChanged);
elector.processWatchEvent(mockZK, mockEvent);
verifyExistCall(3);
// lock node deletion when in standby mode should create znode again
// successful znode creation enters active state and sets monitor
Mockito.when(mockEvent.getType()).thenReturn(Event.EventType.NodeDeleted);
elector.processWatchEvent(mockZK, mockEvent);
// enterNeutralMode not called when app is standby and leader is lost
Mockito.verify(mockApp, Mockito.times(0)).enterNeutralMode();
// once in initial joinElection() and one now
Mockito.verify(mockZK, Mockito.times(2)).create(ZK_LOCK_NAME, data,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
Mockito.verify(mockApp, Mockito.times(1)).becomeActive();
verifyExistCall(4);
// lock node deletion in active mode should enter neutral mode and create
// znode again successful znode creation enters active state and sets
// monitor
Mockito.when(mockEvent.getType()).thenReturn(Event.EventType.NodeDeleted);
elector.processWatchEvent(mockZK, mockEvent);
Mockito.verify(mockApp, Mockito.times(1)).enterNeutralMode();
// another joinElection called
Mockito.verify(mockZK, Mockito.times(3)).create(ZK_LOCK_NAME, data,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
Mockito.verify(mockApp, Mockito.times(2)).becomeActive();
verifyExistCall(5);
// bad path name results in fatal error
Mockito.when(mockEvent.getPath()).thenReturn(null);
elector.processWatchEvent(mockZK, mockEvent);
Mockito.verify(mockApp, Mockito.times(1)).notifyFatalError(
"Unexpected watch error from Zookeeper");
// fatal error means no new connection other than one from constructor
Assert.assertEquals(1, count);
// no new watches after fatal error
verifyExistCall(5);
}
private void verifyExistCall(int times) {
Mockito.verify(mockZK, Mockito.times(times)).exists(
Mockito.eq(ZK_LOCK_NAME), Mockito.<Watcher>any(),
Mockito.same(elector),
Mockito.same(mockZK));
}
/**
* verify becomeStandby is not called if already in standby
*/
@Test
public void testSuccessiveStandbyCalls() {
elector.joinElection(data);
// make the object go into the monitoring standby state
elector.processResult(Code.NODEEXISTS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
Mockito.verify(mockApp, Mockito.times(1)).becomeStandby();
verifyExistCall(1);
WatchedEvent mockEvent = Mockito.mock(WatchedEvent.class);
Mockito.when(mockEvent.getPath()).thenReturn(ZK_LOCK_NAME);
// notify node deletion
// monitoring should be setup again after event is received
Mockito.when(mockEvent.getType()).thenReturn(Event.EventType.NodeDeleted);
elector.processWatchEvent(mockZK, mockEvent);
// is standby. no need to notify anything now
Mockito.verify(mockApp, Mockito.times(0)).enterNeutralMode();
// another joinElection called.
Mockito.verify(mockZK, Mockito.times(2)).create(ZK_LOCK_NAME, data,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
// lost election
elector.processResult(Code.NODEEXISTS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
// still standby. so no need to notify again
Mockito.verify(mockApp, Mockito.times(1)).becomeStandby();
// monitor is set again
verifyExistCall(2);
}
/**
* verify quit election terminates connection and there are no new watches.
* next call to joinElection creates new connection and performs election
*/
@Test
public void testQuitElection() throws Exception {
elector.joinElection(data);
Mockito.verify(mockZK, Mockito.times(0)).close();
elector.quitElection(true);
Mockito.verify(mockZK, Mockito.times(1)).close();
// no watches added
verifyExistCall(0);
byte[] data = new byte[8];
elector.joinElection(data);
// getNewZooKeeper called 2 times. once in constructor and once now
Assert.assertEquals(2, count);
elector.processResult(Code.NODEEXISTS.intValue(), ZK_LOCK_NAME, mockZK,
ZK_LOCK_NAME);
Mockito.verify(mockApp, Mockito.times(1)).becomeStandby();
verifyExistCall(1);
}
/**
* verify that receiveActiveData gives data when active exists, tells that
* active does not exist and reports error in getting active information
*
* @throws IOException
* @throws InterruptedException
* @throws KeeperException
* @throws ActiveNotFoundException
*/
@Test
public void testGetActiveData() throws ActiveNotFoundException,
KeeperException, InterruptedException, IOException {
// get valid active data
byte[] data = new byte[8];
Mockito.when(
mockZK.getData(Mockito.eq(ZK_LOCK_NAME), Mockito.eq(false),
Mockito.<Stat> anyObject())).thenReturn(data);
Assert.assertEquals(data, elector.getActiveData());
Mockito.verify(mockZK, Mockito.times(1)).getData(
Mockito.eq(ZK_LOCK_NAME), Mockito.eq(false),
Mockito.<Stat> anyObject());
// active does not exist
Mockito.when(
mockZK.getData(Mockito.eq(ZK_LOCK_NAME), Mockito.eq(false),
Mockito.<Stat> anyObject())).thenThrow(
new KeeperException.NoNodeException());
try {
elector.getActiveData();
Assert.fail("ActiveNotFoundException expected");
} catch(ActiveNotFoundException e) {
Mockito.verify(mockZK, Mockito.times(2)).getData(
Mockito.eq(ZK_LOCK_NAME), Mockito.eq(false),
Mockito.<Stat> anyObject());
}
// error getting active data rethrows keeperexception
try {
Mockito.when(
mockZK.getData(Mockito.eq(ZK_LOCK_NAME), Mockito.eq(false),
Mockito.<Stat> anyObject())).thenThrow(
new KeeperException.AuthFailedException());
elector.getActiveData();
Assert.fail("KeeperException.AuthFailedException expected");
} catch(KeeperException.AuthFailedException ke) {
Mockito.verify(mockZK, Mockito.times(3)).getData(
Mockito.eq(ZK_LOCK_NAME), Mockito.eq(false),
Mockito.<Stat> anyObject());
}
}
/**
* Test that ensureBaseNode() recursively creates the specified dir
*/
@Test
public void testEnsureBaseNode() throws Exception {
elector.ensureParentZNode();
StringBuilder prefix = new StringBuilder();
for (String part : ZK_PARENT_NAME.split("/")) {
if (part.isEmpty()) continue;
prefix.append("/").append(part);
if (!"/".equals(prefix.toString())) {
Mockito.verify(mockZK).create(
Mockito.eq(prefix.toString()), Mockito.<byte[]>any(),
Mockito.eq(Ids.OPEN_ACL_UNSAFE), Mockito.eq(CreateMode.PERSISTENT));
}
}
}
/**
* Test for a bug encountered during development of HADOOP-8163:
* ensureBaseNode() should throw an exception if it has to retry
* more than 3 times to create any part of the path.
*/
@Test
public void testEnsureBaseNodeFails() throws Exception {
Mockito.doThrow(new KeeperException.ConnectionLossException())
.when(mockZK).create(
Mockito.eq(ZK_PARENT_NAME), Mockito.<byte[]>any(),
Mockito.eq(Ids.OPEN_ACL_UNSAFE), Mockito.eq(CreateMode.PERSISTENT));
try {
elector.ensureParentZNode();
Assert.fail("Did not throw!");
} catch (IOException ioe) {
if (!(ioe.getCause() instanceof KeeperException.ConnectionLossException)) {
throw ioe;
}
}
// Should have tried three times
Mockito.verify(mockZK, Mockito.times(3)).create(
Mockito.eq(ZK_PARENT_NAME), Mockito.<byte[]>any(),
Mockito.eq(Ids.OPEN_ACL_UNSAFE), Mockito.eq(CreateMode.PERSISTENT));
}
/**
* verify the zookeeper connection establishment
*/
@Test
public void testWithoutZKServer() throws Exception {
try {
new ActiveStandbyElector("127.0.0.1", 2000, ZK_PARENT_NAME,
Ids.OPEN_ACL_UNSAFE, Collections.<ZKAuthInfo> emptyList(), mockApp);
Assert.fail("Did not throw zookeeper connection loss exceptions!");
} catch (KeeperException ke) {
GenericTestUtils.assertExceptionContains( "ConnectionLoss", ke);
}
}
/**
* joinElection(..) should happen only after SERVICE_HEALTHY.
*/
@Test
public void testBecomeActiveBeforeServiceHealthy() throws Exception {
mockNoPriorActive();
WatchedEvent mockEvent = Mockito.mock(WatchedEvent.class);
Mockito.when(mockEvent.getType()).thenReturn(Event.EventType.None);
// session expired should enter safe mode
// But for first time, before the SERVICE_HEALTY i.e. appData is set,
// should not enter the election.
Mockito.when(mockEvent.getState()).thenReturn(Event.KeeperState.Expired);
elector.processWatchEvent(mockZK, mockEvent);
// joinElection should not be called.
Mockito.verify(mockZK, Mockito.times(0)).create(ZK_LOCK_NAME, null,
Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, elector, mockZK);
}
}