Java tutorial
/** * 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 com.twitter.distributedlog; import com.twitter.distributedlog.ZooKeeperClient.Credentials; import com.twitter.distributedlog.ZooKeeperClient.DigestCredentials; import org.apache.bookkeeper.stats.NullStatsLogger; import org.apache.bookkeeper.zookeeper.BoundExponentialBackoffRetryPolicy; import org.apache.zookeeper.CreateMode; import org.apache.zookeeper.KeeperException; import org.apache.zookeeper.WatchedEvent; import org.apache.zookeeper.Watcher; import org.apache.zookeeper.Watcher.Event.EventType; import org.apache.zookeeper.Watcher.Event.KeeperState; import org.apache.zookeeper.ZooDefs; import org.apache.zookeeper.ZooKeeper; import org.apache.zookeeper.data.Stat; import org.junit.After; import org.junit.Before; import org.junit.Test; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.IOException; import java.lang.reflect.Field; import java.util.ArrayList; import java.util.List; import java.util.concurrent.CountDownLatch; import java.util.concurrent.ExecutorService; import java.util.concurrent.TimeUnit; import static org.junit.Assert.*; /** * Test Cases for {@link com.twitter.distributedlog.ZooKeeperClient} */ public class TestZooKeeperClient extends ZooKeeperClusterTestCase { static final Logger LOG = LoggerFactory.getLogger(TestZooKeeperClient.class); private final static int sessionTimeoutMs = 2000; private ZooKeeperClient zkc; @Before public void setup() throws Exception { zkc = buildClient(); } @After public void teardown() throws Exception { zkc.close(); } private ZooKeeperClientBuilder clientBuilder() throws Exception { return clientBuilder(sessionTimeoutMs); } private ZooKeeperClientBuilder clientBuilder(int sessionTimeoutMs) throws Exception { return ZooKeeperClientBuilder.newBuilder().name("zkc").uri(DLMTestUtil.createDLMURI(zkPort, "/")) .sessionTimeoutMs(sessionTimeoutMs).zkServers(zkServers) .retryPolicy(new BoundExponentialBackoffRetryPolicy(100, 200, 2)); } private ZooKeeperClient buildClient() throws Exception { return clientBuilder().zkAclId(null).build(); } private ZooKeeperClient buildAuthdClient(String id) throws Exception { return clientBuilder().zkAclId(id).build(); } private void rmAll(ZooKeeperClient client, String path) throws Exception { List<String> nodes = client.get().getChildren(path, false); for (String node : nodes) { String childPath = path + "/" + node; rmAll(client, childPath); } client.get().delete(path, 0); } @Test(timeout = 60000) public void testAclCreatePerms() throws Exception { ZooKeeperClient zkcAuth = buildAuthdClient("test"); zkcAuth.get().create("/test", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); zkcAuth.get().create("/test/key1", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); zkcAuth.get().create("/test/key2", new byte[0], DistributedLogConstants.EVERYONE_READ_CREATOR_ALL, CreateMode.PERSISTENT); ZooKeeperClient zkcNoAuth = buildClient(); zkcNoAuth.get().create("/test/key1/key1", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); try { zkcNoAuth.get().create("/test/key2/key1", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); fail("create should fail on acl protected key"); } catch (KeeperException.NoAuthException ex) { LOG.info("caught exception writing to protected key", ex); } rmAll(zkcAuth, "/test"); } @Test(timeout = 60000) public void testAclNullIdDisablesAuth() throws Exception { ZooKeeperClient zkcAuth = buildAuthdClient(null); zkcAuth.get().create("/test", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); zkcAuth.get().create("/test/key1", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); try { zkcAuth.get().create("/test/key2", new byte[0], DistributedLogConstants.EVERYONE_READ_CREATOR_ALL, CreateMode.PERSISTENT); fail("create should fail because we're not authenticated"); } catch (KeeperException.InvalidACLException ex) { LOG.info("caught exception writing to protected key", ex); } rmAll(zkcAuth, "/test"); } @Test(timeout = 60000) public void testAclAllowsReadsForNoAuth() throws Exception { ZooKeeperClient zkcAuth = buildAuthdClient("test"); zkcAuth.get().create("/test", new byte[0], DistributedLogConstants.EVERYONE_READ_CREATOR_ALL, CreateMode.PERSISTENT); zkcAuth.get().create("/test/key1", new byte[0], DistributedLogConstants.EVERYONE_READ_CREATOR_ALL, CreateMode.PERSISTENT); zkcAuth.get().create("/test/key1/key2", new byte[0], DistributedLogConstants.EVERYONE_READ_CREATOR_ALL, CreateMode.PERSISTENT); ZooKeeperClient zkcNoAuth = buildClient(); List<String> nodes = null; String path = "/test"; nodes = zkcNoAuth.get().getChildren(path, false); path = path + "/" + nodes.get(0); nodes = zkcNoAuth.get().getChildren(path, false); assertEquals("key2", nodes.get(0)); ZooKeeperClient zkcAuth2 = buildAuthdClient("test2"); path = "/test"; nodes = zkcNoAuth.get().getChildren(path, false); path = path + "/" + nodes.get(0); nodes = zkcNoAuth.get().getChildren(path, false); assertEquals("key2", nodes.get(0)); rmAll(zkcAuth, "/test"); } @Test(timeout = 60000) public void testAclDigestCredentialsBasics() throws Exception { ZooKeeperClient zkcAuth = buildClient(); zkcAuth.get().create("/test", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); try { zkcAuth.get().create("/test/key1", new byte[0], DistributedLogConstants.EVERYONE_READ_CREATOR_ALL, CreateMode.PERSISTENT); fail("should have failed"); } catch (Exception ex) { } Credentials credentials = new DigestCredentials("test", "test"); credentials.authenticate(zkcAuth.get()); // Should not throw now that we're authenticated. zkcAuth.get().create("/test/key1", new byte[0], DistributedLogConstants.EVERYONE_READ_CREATOR_ALL, CreateMode.PERSISTENT); rmAll(zkcAuth, "/test"); } @Test(timeout = 60000) public void testAclNoopCredentialsDoesNothing() throws Exception { Credentials.NONE.authenticate(null); } class FailingCredentials implements Credentials { boolean shouldFail = true; @Override public void authenticate(ZooKeeper zooKeeper) { if (shouldFail) { throw new RuntimeException("authfailed"); } } public void setShouldFail(boolean shouldFail) { this.shouldFail = shouldFail; } } @Test(timeout = 60000) public void testAclFailedAuthenticationCanBeRecovered() throws Exception { FailingCredentials credentials = new FailingCredentials(); ZooKeeperClient zkc = new ZooKeeperClient("test", 2000, 2000, zkServers, null, NullStatsLogger.INSTANCE, 1, 10000, credentials); try { zkc.get(); fail("should have failed on auth"); } catch (Exception ex) { assertEquals("authfailed", ex.getMessage()); } // Should recover fine credentials.setShouldFail(false); zkc.get().create("/test", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); rmAll(zkc, "/test"); } private void expireZooKeeperSession(ZooKeeper zk, int timeout) throws IOException, InterruptedException, KeeperException { final CountDownLatch latch = new CountDownLatch(1); ZooKeeper newZk = new ZooKeeper(zkServers, timeout, new Watcher() { @Override public void process(WatchedEvent event) { if (event.getType() == EventType.None && event.getState() == KeeperState.SyncConnected) { latch.countDown(); } } }, zk.getSessionId(), zk.getSessionPasswd()); if (!latch.await(timeout, TimeUnit.MILLISECONDS)) { throw KeeperException.create(KeeperException.Code.CONNECTIONLOSS); } newZk.close(); } private CountDownLatch awaitConnectionEvent(final KeeperState state, final ZooKeeperClient zkc) { final CountDownLatch connected = new CountDownLatch(1); Watcher watcher = new Watcher() { @Override public void process(WatchedEvent event) { if (event.getType() == EventType.None && event.getState() == state) { connected.countDown(); } } }; zkc.register(watcher); return connected; } @Test(timeout = 60000) public void testAclAuthSpansExpiration() throws Exception { ZooKeeperClient zkcAuth = buildAuthdClient("test"); zkcAuth.get().create("/test", new byte[0], DistributedLogConstants.EVERYONE_READ_CREATOR_ALL, CreateMode.PERSISTENT); CountDownLatch expired = awaitConnectionEvent(KeeperState.Expired, zkcAuth); CountDownLatch connected = awaitConnectionEvent(KeeperState.SyncConnected, zkcAuth); expireZooKeeperSession(zkcAuth.get(), 2000); expired.await(2, TimeUnit.SECONDS); connected.await(2, TimeUnit.SECONDS); zkcAuth.get().create("/test/key1", new byte[0], DistributedLogConstants.EVERYONE_READ_CREATOR_ALL, CreateMode.PERSISTENT); rmAll(zkcAuth, "/test"); } @Test(timeout = 60000) public void testAclAuthSpansExpirationNonRetryableClient() throws Exception { ZooKeeperClient zkcAuth = clientBuilder().retryPolicy(null).zkAclId("test").build(); zkcAuth.get().create("/test", new byte[0], DistributedLogConstants.EVERYONE_READ_CREATOR_ALL, CreateMode.PERSISTENT); CountDownLatch expired = awaitConnectionEvent(KeeperState.Expired, zkcAuth); CountDownLatch connected = awaitConnectionEvent(KeeperState.SyncConnected, zkcAuth); expireZooKeeperSession(zkcAuth.get(), 2000); expired.await(2, TimeUnit.SECONDS); connected.await(2, TimeUnit.SECONDS); zkcAuth.get().create("/test/key1", new byte[0], DistributedLogConstants.EVERYONE_READ_CREATOR_ALL, CreateMode.PERSISTENT); rmAll(zkcAuth, "/test"); } static class TestWatcher implements Watcher { final List<WatchedEvent> receivedEvents = new ArrayList<WatchedEvent>(); CountDownLatch latch = new CountDownLatch(0); public TestWatcher setLatch(CountDownLatch latch) { this.latch = latch; return this; } @Override public void process(WatchedEvent event) { if (event.getType() == Event.EventType.NodeDataChanged) { synchronized (receivedEvents) { receivedEvents.add(event); } latch.countDown(); } } } @Test(timeout = 60000) public void testRegisterUnregisterWatchers() throws Exception { TestWatcher w1 = new TestWatcher(); TestWatcher w2 = new TestWatcher(); final CountDownLatch latch = new CountDownLatch(2); w1.setLatch(latch); w2.setLatch(latch); zkc.register(w1); zkc.register(w2); assertEquals(2, zkc.watchers.size()); final String zkPath = "/test-register-unregister-watchers"; zkc.get().create(zkPath, new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); zkc.get().getData(zkPath, true, new Stat()); zkc.get().setData(zkPath, "first-set".getBytes(), -1); latch.await(); assertEquals(1, w1.receivedEvents.size()); assertEquals(zkPath, w1.receivedEvents.get(0).getPath()); assertEquals(Watcher.Event.EventType.NodeDataChanged, w1.receivedEvents.get(0).getType()); assertEquals(1, w2.receivedEvents.size()); assertEquals(zkPath, w2.receivedEvents.get(0).getPath()); assertEquals(Watcher.Event.EventType.NodeDataChanged, w2.receivedEvents.get(0).getType()); final CountDownLatch latch1 = new CountDownLatch(1); final CountDownLatch latch2 = new CountDownLatch(1); w1.setLatch(latch1); w2.setLatch(latch2); zkc.unregister(w2); assertEquals(1, zkc.watchers.size()); zkc.get().getData(zkPath, true, new Stat()); zkc.get().setData(zkPath, "second-set".getBytes(), -1); latch1.await(); assertEquals(2, w1.receivedEvents.size()); assertEquals(zkPath, w1.receivedEvents.get(1).getPath()); assertEquals(Watcher.Event.EventType.NodeDataChanged, w1.receivedEvents.get(1).getType()); assertFalse(latch2.await(2, TimeUnit.SECONDS)); assertEquals(1, w2.receivedEvents.size()); } @Test(timeout = 60000) public void testExceptionOnWatchers() throws Exception { TestWatcher w1 = new TestWatcher(); TestWatcher w2 = new TestWatcher(); final CountDownLatch latch = new CountDownLatch(2); w1.setLatch(latch); w2.setLatch(latch); zkc.register(w1); zkc.register(w2); // register bad watcher zkc.register(new Watcher() { @Override public void process(WatchedEvent event) { throw new NullPointerException("bad watcher returning null"); } }); assertEquals(3, zkc.watchers.size()); final String zkPath = "/test-exception-on-watchers"; zkc.get().create(zkPath, new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); zkc.get().getData(zkPath, true, new Stat()); zkc.get().setData(zkPath, "first-set".getBytes(), -1); latch.await(); assertEquals(1, w1.receivedEvents.size()); assertEquals(zkPath, w1.receivedEvents.get(0).getPath()); assertEquals(Watcher.Event.EventType.NodeDataChanged, w1.receivedEvents.get(0).getType()); assertEquals(1, w2.receivedEvents.size()); assertEquals(zkPath, w2.receivedEvents.get(0).getPath()); assertEquals(Watcher.Event.EventType.NodeDataChanged, w2.receivedEvents.get(0).getType()); } @Test(timeout = 60000) public void testZooKeeperReconnection() throws Exception { int sessionTimeoutMs = 100; ZooKeeperClient zkc = clientBuilder(sessionTimeoutMs).zkAclId(null).build(); ZooKeeper zk = zkc.get(); long sessionId = zk.getSessionId(); ZooKeeperClientUtils.expireSession(zkc, zkServers, 2 * sessionTimeoutMs); ZooKeeper newZk = zkc.get(); while (!ZooKeeper.States.CONNECTED.equals(newZk.getState())) { TimeUnit.MILLISECONDS.sleep(sessionTimeoutMs / 2); } long newSessionId = newZk.getSessionId(); assertTrue(newZk == zk); assertFalse(sessionId == newSessionId); } @Test(timeout = 60000) public void testZooKeeperReconnectionBlockingRetryThread() throws Exception { int sessionTimeoutMs = 100; ZooKeeperClient zkc = clientBuilder(sessionTimeoutMs).zkAclId(null).build(); ZooKeeper zk = zkc.get(); assertTrue(zk instanceof org.apache.bookkeeper.zookeeper.ZooKeeperClient); org.apache.bookkeeper.zookeeper.ZooKeeperClient bkZkc = (org.apache.bookkeeper.zookeeper.ZooKeeperClient) zk; // get the connect executor Field connectExecutorField = bkZkc.getClass().getDeclaredField("connectExecutor"); connectExecutorField.setAccessible(true); ExecutorService connectExecutor = (ExecutorService) connectExecutorField.get(bkZkc); final CountDownLatch latch = new CountDownLatch(1); // block retry thread in the zookeeper client connectExecutor.submit(new Runnable() { @Override public void run() { try { latch.await(); } catch (InterruptedException e) { } } }); ZooKeeperClientUtils.expireSession(zkc, zkServers, 2 * sessionTimeoutMs); ZooKeeper newZk; while ((newZk = zkc.get()) == zk) { TimeUnit.MILLISECONDS.sleep(sessionTimeoutMs / 2); } assertEquals(ZooKeeper.States.CONNECTED, newZk.getState()); } }