Java tutorial
/** * Copyright 2016 Yahoo Inc. * * Licensed 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.yahoo.pulsar.zookeeper; import static org.testng.Assert.assertEquals; import static org.testng.Assert.assertFalse; import static org.testng.Assert.fail; import static org.testng.AssertJUnit.assertNotNull; import static org.testng.AssertJUnit.assertNull; import java.util.Set; import java.util.TreeSet; import java.util.concurrent.CompletableFuture; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.ScheduledThreadPoolExecutor; import java.util.concurrent.atomic.AtomicInteger; import org.apache.bookkeeper.util.OrderedSafeExecutor; import org.apache.zookeeper.KeeperException.Code; import org.apache.zookeeper.MockZooKeeper; import org.apache.zookeeper.WatchedEvent; import org.apache.zookeeper.Watcher.Event; import org.apache.zookeeper.Watcher.Event.KeeperState; import org.apache.zookeeper.ZooKeeper; import org.testng.Assert; import org.testng.annotations.AfterMethod; import org.testng.annotations.BeforeMethod; import org.testng.annotations.Test; import com.google.common.collect.Lists; import com.google.common.collect.Sets; import com.google.common.util.concurrent.MoreExecutors; @Test public class ZookeeperCacheTest { private MockZooKeeper zkClient; @BeforeMethod void setup() throws Exception { zkClient = MockZooKeeper.newInstance(MoreExecutors.sameThreadExecutor()); } @AfterMethod void teardown() throws Exception { zkClient.shutdown(); } @Test void testSimpleCache() throws Exception { ZooKeeperCache zkCacheService = new LocalZooKeeperCache(zkClient, null /* no executors in unit test */); ZooKeeperDataCache<String> zkCache = new ZooKeeperDataCache<String>(zkCacheService) { @Override public String deserialize(String key, byte[] content) throws Exception { return new String(content); } }; String value = "test"; zkClient.create("/my_test", value.getBytes(), null, null); assertEquals(zkCache.get("/my_test").get(), value); String newValue = "test2"; zkClient.setData("/my_test", newValue.getBytes(), -1); // Wait for the watch to be triggered Thread.sleep(100); assertEquals(zkCache.get("/my_test").get(), newValue); zkCacheService.process(new WatchedEvent(Event.EventType.None, KeeperState.Expired, null)); assertEquals(zkCache.get("/my_test").get(), newValue); zkClient.failNow(Code.SESSIONEXPIRED); assertEquals(zkCache.get("/my_test").get(), newValue); try { zkCache.get("/other"); fail("shuld have thrown exception"); } catch (Exception e) { // Ok } } @Test void testChildrenCache() throws Exception { OrderedSafeExecutor executor = new OrderedSafeExecutor(1, "test"); zkClient.create("/test", new byte[0], null, null); ZooKeeperCache zkCacheService = new LocalZooKeeperCache(zkClient, executor); ZooKeeperChildrenCache cache = new ZooKeeperChildrenCache(zkCacheService, "/test"); // Create callback counter AtomicInteger notificationCount = new AtomicInteger(0); ZooKeeperCacheListener<Set<String>> counter = (path, data, stat) -> { notificationCount.incrementAndGet(); }; // Register counter twice and unregister once, so callback should be counted correctly cache.registerListener(counter); cache.registerListener(counter); cache.unregisterListener(counter); assertEquals(notificationCount.get(), 0); assertEquals(cache.get(), Sets.newTreeSet()); zkClient.create("/test/z1", new byte[0], null, null); zkClient.create("/test/z2", new byte[0], null, null); // Wait for cache to be updated in background while (notificationCount.get() < 2) { Thread.sleep(1); } assertEquals(cache.get(), new TreeSet<String>(Lists.newArrayList("z1", "z2"))); assertEquals(cache.get("/test"), new TreeSet<String>(Lists.newArrayList("z1", "z2"))); assertEquals(notificationCount.get(), 2); zkClient.delete("/test/z2", -1); while (notificationCount.get() < 3) { Thread.sleep(1); } assertEquals(cache.get(), new TreeSet<String>(Lists.newArrayList("z1"))); assertEquals(cache.get(), new TreeSet<String>(Lists.newArrayList("z1"))); zkCacheService.process(new WatchedEvent(Event.EventType.None, KeeperState.Expired, null)); zkClient.failNow(Code.SESSIONEXPIRED); try { cache.get(); fail("shuld have thrown exception"); } catch (Exception e) { // Ok } assertEquals(notificationCount.get(), 3); } @Test void testExistsCache() throws Exception { // Check existence after creation of the node zkClient.create("/test", new byte[0], null, null); Thread.sleep(20); ZooKeeperCache zkCacheService = new LocalZooKeeperCache(zkClient, null /* no executor in unit test */); boolean exists = zkCacheService.exists("/test"); Assert.assertTrue(exists, "/test should exists in the cache"); // Check existence after deletion if the node zkClient.delete("/test", -1); Thread.sleep(20); boolean shouldNotExist = zkCacheService.exists("/test"); Assert.assertFalse(shouldNotExist, "/test should not exist in the cache"); } @Test void testInvalidateCache() throws Exception { zkClient.create("/test", new byte[0], null, null); zkClient.create("/test/c1", new byte[0], null, null); zkClient.create("/test/c2", new byte[0], null, null); Thread.sleep(20); ZooKeeperCache zkCacheService = new LocalZooKeeperCache(zkClient, null /* no executor in unit test */); boolean exists = zkCacheService.exists("/test"); Assert.assertTrue(exists, "/test should exists in the cache"); assertNull(zkCacheService.getChildrenIfPresent("/test")); assertNotNull(zkCacheService.getChildren("/test")); assertNotNull(zkCacheService.getChildrenIfPresent("/test")); zkCacheService.invalidateAllChildren(); assertNull(zkCacheService.getChildrenIfPresent("/test")); assertNull(zkCacheService.getDataIfPresent("/test")); assertNotNull(zkCacheService.getData("/test", Deserializers.STRING_DESERIALIZER)); assertNotNull(zkCacheService.getDataIfPresent("/test")); zkCacheService.invalidateData("/test"); assertNull(zkCacheService.getDataIfPresent("/test")); assertNotNull(zkCacheService.getChildren("/test")); assertNotNull(zkCacheService.getData("/test", Deserializers.STRING_DESERIALIZER)); zkCacheService.invalidateAll(); assertNull(zkCacheService.getChildrenIfPresent("/test")); assertNull(zkCacheService.getDataIfPresent("/test")); assertNotNull(zkCacheService.getChildren("/test")); zkCacheService.invalidateRoot("/test"); assertNull(zkCacheService.getChildrenIfPresent("/test")); } @Test void testGlobalZooKeeperCache() throws Exception { OrderedSafeExecutor executor = new OrderedSafeExecutor(1, "test"); ScheduledExecutorService scheduledExecutor = new ScheduledThreadPoolExecutor(1); MockZooKeeper zkc = MockZooKeeper.newInstance(); ZooKeeperClientFactory zkClientfactory = new ZooKeeperClientFactory() { @Override public CompletableFuture<ZooKeeper> create(String serverList, SessionType sessionType, int zkSessionTimeoutMillis) { return CompletableFuture.completedFuture(zkc); } }; GlobalZooKeeperCache zkCacheService = new GlobalZooKeeperCache(zkClientfactory, -1, "", executor, scheduledExecutor); zkCacheService.start(); zkClient = (MockZooKeeper) zkCacheService.getZooKeeper(); ZooKeeperDataCache<String> zkCache = new ZooKeeperDataCache<String>(zkCacheService) { @Override public String deserialize(String key, byte[] content) throws Exception { return new String(content); } }; // Create callback counter AtomicInteger notificationCount = new AtomicInteger(0); ZooKeeperCacheListener<String> counter = (path, data, stat) -> { notificationCount.incrementAndGet(); }; // Register counter twice and unregister once, so callback should be counted correctly zkCache.registerListener(counter); zkCache.registerListener(counter); zkCache.unregisterListener(counter); String value = "test"; zkClient.create("/my_test", value.getBytes(), null, null); assertEquals(zkCache.get("/my_test").get(), value); String newValue = "test2"; // case 1: update and create znode directly and verify that the cache is retrieving the correct data assertEquals(notificationCount.get(), 0); zkClient.setData("/my_test", newValue.getBytes(), -1); zkClient.create("/my_test2", value.getBytes(), null, null); // Wait for the watch to be triggered while (notificationCount.get() < 1) { Thread.sleep(1); } // retrieve the data from the cache and verify it is the updated/new data assertEquals(zkCache.get("/my_test").get(), newValue); assertEquals(zkCache.get("/my_test2").get(), value); // The callback method should be called just only once assertEquals(notificationCount.get(), 1); // case 2: force the ZooKeeper session to be expired and verify that the data is still accessible zkCacheService.process(new WatchedEvent(Event.EventType.None, KeeperState.Expired, null)); assertEquals(zkCache.get("/my_test").get(), newValue); assertEquals(zkCache.get("/my_test2").get(), value); // case 3: update the znode directly while the client session is marked as expired. Verify that the new updates // is not seen in the cache zkClient.create("/other", newValue.getBytes(), null, null); zkClient.failNow(Code.SESSIONEXPIRED); assertEquals(zkCache.get("/my_test").get(), newValue); assertEquals(zkCache.get("/my_test2").get(), value); try { zkCache.get("/other"); fail("shuld have thrown exception"); } catch (Exception e) { // Ok } // case 4: directly delete the znode while the session is not re-connected yet. Verify that the deletion is not // seen by the cache zkClient.failAfter(-1, Code.OK); zkClient.delete("/my_test2", -1); zkCacheService.process(new WatchedEvent(Event.EventType.None, KeeperState.SyncConnected, null)); assertEquals(zkCache.get("/other").get(), newValue); // Make sure that the value is now directly from ZK and deleted assertFalse(zkCache.get("/my_test2").isPresent()); // case 5: trigger a ZooKeeper disconnected event and make sure the cache content is not changed. zkCacheService.process(new WatchedEvent(Event.EventType.None, KeeperState.Disconnected, null)); zkClient.create("/other2", newValue.getBytes(), null, null); // case 6: trigger a ZooKeeper SyncConnected event and make sure that the cache content is invalidated s.t. we // can see the updated content now zkCacheService.process(new WatchedEvent(Event.EventType.None, KeeperState.SyncConnected, null)); // make sure that we get it assertEquals(zkCache.get("/other2").get(), newValue); zkCacheService.close(); executor.shutdown(); // Update shouldn't happen after the last check assertEquals(notificationCount.get(), 1); } }