Examples with Event org.apache.zookeeper.Watcher.Event used on opensource projects

Example 1 with Event

use of org.apache.zookeeper.Watcher.Event in project pulsar by yahoo.

the class ZookeeperCacheTest method testGlobalZooKeeperCache.

@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);
}