WatcherTest.java
/*
* 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.zookeeper.test;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.junit.jupiter.api.Assertions.fail;
import java.io.IOException;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.apache.zookeeper.AsyncCallback.StatCallback;
import org.apache.zookeeper.AsyncCallback.VoidCallback;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.TestableZooKeeper;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event;
import org.apache.zookeeper.Watcher.Event.EventType;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.client.ZKClientConfig;
import org.apache.zookeeper.data.Stat;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class WatcherTest extends ClientBase {
protected static final Logger LOG = LoggerFactory.getLogger(WatcherTest.class);
private long timeOfLastWatcherInvocation;
private static final class MyStatCallback implements StatCallback {
int rc;
public void processResult(int rc, String path, Object ctx, Stat stat) {
((int[]) ctx)[0]++;
this.rc = rc;
}
}
private class MyWatcher extends CountdownWatcher {
LinkedBlockingQueue<WatchedEvent> events = new LinkedBlockingQueue<>();
public void process(WatchedEvent event) {
super.process(event);
if (event.getType() != Event.EventType.None) {
timeOfLastWatcherInvocation = System.currentTimeMillis();
try {
events.put(event);
} catch (InterruptedException e) {
LOG.warn("ignoring interrupt during event.put");
}
}
}
}
@BeforeEach
public void setUp() throws Exception {
super.setUp();
// Reset to default value since some test cases set this to true.
// Needed for JDK7 since unit test can run is random order
System.setProperty(ZKClientConfig.DISABLE_AUTO_WATCH_RESET, "false");
}
/**
* Verify that we get all of the events we expect to get. This particular
* case verifies that we see all of the data events on a particular node.
* There was a bug (ZOOKEEPER-137) that resulted in events being dropped
* in some cases (timing).
*
* @throws IOException
* @throws InterruptedException
* @throws KeeperException
*/
@Test
public void testWatcherCorrectness() throws IOException, InterruptedException, KeeperException {
ZooKeeper zk = null;
try {
MyWatcher watcher = new MyWatcher();
zk = createClient(watcher, hostPort);
StatCallback scb = new StatCallback() {
public void processResult(int rc, String path, Object ctx, Stat stat) {
// don't do anything
}
};
VoidCallback vcb = new VoidCallback() {
public void processResult(int rc, String path, Object ctx) {
// don't do anything
}
};
String[] names = new String[10];
for (int i = 0; i < names.length; i++) {
String name = zk.create("/tc-", "initialvalue".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT_SEQUENTIAL);
names[i] = name;
Stat stat = new Stat();
zk.getData(name, watcher, stat);
zk.setData(name, "new".getBytes(), stat.getVersion(), scb, null);
stat = zk.exists(name, watcher);
zk.delete(name, stat.getVersion(), vcb, null);
}
for (int i = 0; i < names.length; i++) {
String name = names[i];
WatchedEvent event = watcher.events.poll(10, TimeUnit.SECONDS);
assertEquals(name, event.getPath());
assertEquals(Event.EventType.NodeDataChanged, event.getType());
assertEquals(Event.KeeperState.SyncConnected, event.getState());
event = watcher.events.poll(10, TimeUnit.SECONDS);
assertEquals(name, event.getPath());
assertEquals(Event.EventType.NodeDeleted, event.getType());
assertEquals(Event.KeeperState.SyncConnected, event.getState());
}
} finally {
if (zk != null) {
zk.close();
}
}
}
@Test
public void testWatcherDisconnectOnClose() throws IOException, InterruptedException, KeeperException {
ZooKeeper zk = null;
try {
final BlockingQueue<WatchedEvent> queue = new LinkedBlockingQueue<>();
MyWatcher connWatcher = new MyWatcher();
Watcher watcher = event -> {
try {
queue.put(event);
} catch (InterruptedException e) {
// Oh well, never mind
}
};
zk = createClient(connWatcher, hostPort);
StatCallback scb = new StatCallback() {
public void processResult(int rc, String path, Object ctx, Stat stat) {
// don't do anything
}
};
// Register a watch on the node
zk.exists("/missing", watcher, scb, null);
// Close the client without changing the node
zk.close();
WatchedEvent event = queue.poll(10, TimeUnit.SECONDS);
assertNotNull(event, "No watch event was received after closing the Zookeeper client. A 'Closed' event should have occurred");
assertEquals(Event.EventType.None, event.getType(), "Closed events are not generated by the server, and so should have a type of 'None'");
assertEquals(Event.KeeperState.Closed, event.getState(), "A 'Closed' event was expected as the Zookeeper client was closed without altering the node it was watching");
} finally {
if (zk != null) {
zk.close();
}
}
}
@Test
public void testWatcherCount() throws IOException, InterruptedException, KeeperException {
ZooKeeper zk1 = null, zk2 = null;
try {
MyWatcher w1 = new MyWatcher();
zk1 = createClient(w1, hostPort);
MyWatcher w2 = new MyWatcher();
zk2 = createClient(w2, hostPort);
Stat stat = new Stat();
zk1.create("/watch-count-test", "value".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
zk1.create("/watch-count-test-2", "value".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
zk1.getData("/watch-count-test", w1, stat);
zk1.getData("/watch-count-test-2", w1, stat);
zk2.getData("/watch-count-test", w2, stat);
assertEquals(serverFactory.getZooKeeperServer().getZKDatabase().getDataTree().getWatchCount(), 3);
} finally {
if (zk1 != null) {
zk1.close();
}
if (zk2 != null) {
zk2.close();
}
}
}
static final int COUNT = 100;
/**
* This test checks that watches for pending requests do not get triggered,
* but watches set by previous requests do.
*
* @throws Exception
*/
@Test
public void testWatchAutoResetWithPending() throws Exception {
MyWatcher[] watches = new MyWatcher[COUNT];
MyStatCallback[] cbs = new MyStatCallback[COUNT];
MyWatcher watcher = new MyWatcher();
int[] count = new int[1];
TestableZooKeeper zk = createClient(watcher, hostPort, 6000);
ZooKeeper zk2 = createClient(watcher, hostPort, 5000);
zk2.create("/test", new byte[0], Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
for (int i = 0; i < COUNT / 2; i++) {
watches[i] = new MyWatcher();
cbs[i] = new MyStatCallback();
zk.exists("/test", watches[i], cbs[i], count);
}
zk.exists("/test", false);
assertTrue(zk.pauseCnxn(3000), "Failed to pause the connection!");
zk2.close();
stopServer();
watches[0].waitForDisconnected(60000);
for (int i = COUNT / 2; i < COUNT; i++) {
watches[i] = new MyWatcher();
cbs[i] = new MyStatCallback();
zk.exists("/test", watches[i], cbs[i], count);
}
startServer();
watches[COUNT / 2 - 1].waitForConnected(60000);
assertEquals(null, zk.exists("/test", false));
waitForAllWatchers();
for (int i = 0; i < COUNT / 2; i++) {
assertEquals(1, watches[i].events.size(), "For " + i);
}
for (int i = COUNT / 2; i < COUNT; i++) {
if (cbs[i].rc == KeeperException.Code.OK.intValue()) {
assertEquals(1, watches[i].events.size(), "For " + i);
} else {
assertEquals(0, watches[i].events.size(), "For " + i);
}
}
assertEquals(COUNT, count[0]);
zk.close();
}
/**
* Wait until no watcher has been fired in the last second to ensure that all watches
* that are waiting to be fired have been fired
* @throws Exception
*/
private void waitForAllWatchers() throws Exception {
timeOfLastWatcherInvocation = System.currentTimeMillis();
while (System.currentTimeMillis() - timeOfLastWatcherInvocation < 1000) {
Thread.sleep(1000);
}
}
final int TIMEOUT = 5000;
@Test
public void testWatcherAutoResetWithGlobal() throws Exception {
ZooKeeper zk = null;
MyWatcher watcher = new MyWatcher();
zk = createClient(watcher, hostPort, TIMEOUT);
testWatcherAutoReset(zk, watcher, watcher);
zk.close();
}
@Test
public void testWatcherAutoResetWithLocal() throws Exception {
ZooKeeper zk = null;
MyWatcher watcher = new MyWatcher();
zk = createClient(watcher, hostPort, TIMEOUT);
testWatcherAutoReset(zk, watcher, new MyWatcher());
zk.close();
}
@Test
public void testWatcherAutoResetDisabledWithGlobal() throws Exception {
/**
* When ZooKeeper is created this property will get used.
*/
System.setProperty(ZKClientConfig.DISABLE_AUTO_WATCH_RESET, "true");
testWatcherAutoResetWithGlobal();
}
@Test
public void testWatcherAutoResetDisabledWithLocal() throws Exception {
System.setProperty(ZKClientConfig.DISABLE_AUTO_WATCH_RESET, "true");
testWatcherAutoResetWithLocal();
}
private void testWatcherAutoReset(ZooKeeper zk, MyWatcher globalWatcher, MyWatcher localWatcher) throws Exception {
boolean isGlobal = (localWatcher == globalWatcher);
// First test to see if the watch survives across reconnects
zk.create("/watchtest", new byte[0], Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
zk.create("/watchtest/child", new byte[0], Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
if (isGlobal) {
zk.getChildren("/watchtest", true);
zk.getData("/watchtest/child", true, new Stat());
zk.exists("/watchtest/child2", true);
} else {
zk.getChildren("/watchtest", localWatcher);
zk.getData("/watchtest/child", localWatcher, new Stat());
zk.exists("/watchtest/child2", localWatcher);
}
assertTrue(localWatcher.events.isEmpty());
stopServer();
globalWatcher.waitForDisconnected(3000);
localWatcher.waitForDisconnected(500);
startServer();
globalWatcher.waitForConnected(3000);
boolean disableAutoWatchReset = zk.getClientConfig().getBoolean(ZKClientConfig.DISABLE_AUTO_WATCH_RESET);
if (!isGlobal && !disableAutoWatchReset) {
localWatcher.waitForConnected(500);
}
assertTrue(localWatcher.events.isEmpty());
zk.setData("/watchtest/child", new byte[1], -1);
zk.create("/watchtest/child2", new byte[0], Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
WatchedEvent e;
if (!disableAutoWatchReset) {
e = localWatcher.events.poll(TIMEOUT, TimeUnit.MILLISECONDS);
assertEquals(EventType.NodeDataChanged, e.getType(), e.getPath());
assertEquals("/watchtest/child", e.getPath());
} else {
// we'll catch this later if it does happen after timeout, so
// why waste the time on poll
}
if (!disableAutoWatchReset) {
e = localWatcher.events.poll(TIMEOUT, TimeUnit.MILLISECONDS);
// The create will trigger the get children and the exist
// watches
assertEquals(EventType.NodeCreated, e.getType());
assertEquals("/watchtest/child2", e.getPath());
} else {
// we'll catch this later if it does happen after timeout, so
// why waste the time on poll
}
if (!disableAutoWatchReset) {
e = localWatcher.events.poll(TIMEOUT, TimeUnit.MILLISECONDS);
assertEquals(EventType.NodeChildrenChanged, e.getType());
assertEquals("/watchtest", e.getPath());
} else {
// we'll catch this later if it does happen after timeout, so
// why waste the time on poll
}
assertTrue(localWatcher.events.isEmpty()); // ensure no late arrivals
stopServer();
globalWatcher.waitForDisconnected(TIMEOUT);
try {
try {
localWatcher.waitForDisconnected(500);
if (!isGlobal && !disableAutoWatchReset) {
fail("Got an event when I shouldn't have");
}
} catch (TimeoutException toe) {
if (disableAutoWatchReset) {
fail("Didn't get an event when I should have");
}
// Else what we are expecting since there are no outstanding watches
}
} catch (Exception e1) {
LOG.error("bad", e1);
throw new RuntimeException(e1);
}
startServer();
globalWatcher.waitForConnected(TIMEOUT);
if (isGlobal) {
zk.getChildren("/watchtest", true);
zk.getData("/watchtest/child", true, new Stat());
zk.exists("/watchtest/child2", true);
} else {
zk.getChildren("/watchtest", localWatcher);
zk.getData("/watchtest/child", localWatcher, new Stat());
zk.exists("/watchtest/child2", localWatcher);
}
// Do trigger an event to make sure that we do not get
// it later
zk.delete("/watchtest/child2", -1);
e = localWatcher.events.poll(TIMEOUT, TimeUnit.MILLISECONDS);
assertEquals(EventType.NodeDeleted, e.getType());
assertEquals("/watchtest/child2", e.getPath());
e = localWatcher.events.poll(TIMEOUT, TimeUnit.MILLISECONDS);
assertEquals(EventType.NodeChildrenChanged, e.getType());
assertEquals("/watchtest", e.getPath());
assertTrue(localWatcher.events.isEmpty());
stopServer();
globalWatcher.waitForDisconnected(TIMEOUT);
localWatcher.waitForDisconnected(500);
startServer();
globalWatcher.waitForConnected(TIMEOUT);
if (!isGlobal && !disableAutoWatchReset) {
localWatcher.waitForConnected(500);
}
zk.delete("/watchtest/child", -1);
zk.delete("/watchtest", -1);
if (!disableAutoWatchReset) {
e = localWatcher.events.poll(TIMEOUT, TimeUnit.MILLISECONDS);
assertEquals(EventType.NodeDeleted, e.getType());
assertEquals("/watchtest/child", e.getPath());
} else {
// we'll catch this later if it does happen after timeout, so
// why waste the time on poll
}
// Make sure nothing is straggling!
Thread.sleep(1000);
assertTrue(localWatcher.events.isEmpty());
}
}