Java tutorial
/* Copyright (c) 2014 LinkedIn Corp. 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.linkedin.d2.discovery.stores.zk; import com.linkedin.common.callback.FutureCallback; import com.linkedin.common.util.None; import org.apache.zookeeper.AsyncCallback; import org.apache.zookeeper.KeeperException; import org.apache.zookeeper.WatchedEvent; import org.apache.zookeeper.Watcher; import org.apache.zookeeper.data.Stat; import org.testng.Assert; import org.testng.annotations.AfterSuite; import org.testng.annotations.BeforeSuite; import org.testng.annotations.Test; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.util.List; import java.util.concurrent.CountDownLatch; import java.util.concurrent.ExecutionException; import java.util.concurrent.TimeUnit; /** * @author Ang Xu * @version $Revision: $ */ public class SymlinkAwareZooKeeperTest { private ZKConnection _zkClient; private ZKServer _zkServer; private int _port; @BeforeSuite public void setup() throws InterruptedException, ExecutionException, IOException { _port = 11830; try { _zkServer = new ZKServer(_port); _zkServer.startup(); _zkClient = new ZKConnection("localhost:" + _port, 5001, 0, false, null, 0, false, true); _zkClient.start(); } catch (IOException e) { Assert.fail("unable to instantiate real zk server on port " + _port); } initTestData(); } @AfterSuite public void tearDown() throws IOException, InterruptedException { _zkClient.shutdown(); _zkServer.shutdown(); } private void initTestData() throws ExecutionException, InterruptedException, UnsupportedEncodingException { FutureCallback<None> callback; for (int i = 1; i <= 10; i++) { callback = new FutureCallback<None>(); _zkClient.ensurePersistentNodeExists("/foo/bar/" + i, callback); callback.get(); callback = new FutureCallback<None>(); _zkClient.setDataUnsafe("/foo/bar/" + i, String.valueOf(i).getBytes("UTF-8"), callback); callback.get(); } for (int i = 11; i <= 15; i++) { callback = new FutureCallback<None>(); _zkClient.ensurePersistentNodeExists("/bar/foo/" + i, callback); callback.get(); callback = new FutureCallback<None>(); _zkClient.setDataUnsafe("/bar/foo/" + i, String.valueOf(i).getBytes("UTF-8"), callback); callback.get(); } callback = new FutureCallback<None>(); _zkClient.createSymlink("/foo/$link", "/foo/bar", callback); callback.get(); callback = new FutureCallback<None>(); _zkClient.createSymlink("/$bar", "/foo", callback); callback.get(); } @Test public void testSymlinkExists() throws InterruptedException { final CountDownLatch latch = new CountDownLatch(1); AsyncCallback.StatCallback callback = new AsyncCallback.StatCallback() { @Override public void processResult(int rc, String path, Object ctx, Stat stat) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.OK); Assert.assertEquals(path, "/foo/$link"); Assert.assertNotNull(stat); latch.countDown(); } }; _zkClient.getZooKeeper().exists("/foo/$link", null, callback, null); latch.await(30, TimeUnit.SECONDS); } @Test public void testSymlinkGetChildren() throws InterruptedException, ExecutionException, IOException { final CountDownLatch latch = new CountDownLatch(1); AsyncCallback.ChildrenCallback callback = new AsyncCallback.ChildrenCallback() { @Override public void processResult(int rc, String path, Object ctx, List<String> children) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.OK); Assert.assertEquals(path, "/foo/$link"); Assert.assertEquals(children.size(), 10); latch.countDown(); } }; // symlink: /foo/$link -> /foo/bar _zkClient.getZooKeeper().getChildren("/foo/$link", null, callback, null); latch.await(30, TimeUnit.SECONDS); } @Test public void testSymlinkGetChildren2() throws InterruptedException, ExecutionException, IOException, KeeperException { final CountDownLatch latch = new CountDownLatch(1); Stat expectedStat = _zkClient.getZooKeeper().exists("/foo/bar", false); AsyncCallback.Children2Callback callback = new AsyncCallback.Children2Callback() { @Override public void processResult(int rc, String path, Object ctx, List<String> children, Stat stat) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.OK); Assert.assertEquals(path, "/foo/$link"); Assert.assertEquals(children.size(), 10); Assert.assertEquals(stat, expectedStat); latch.countDown(); } }; // symlink: /foo/$link -> /foo/bar _zkClient.getZooKeeper().getChildren("/foo/$link", null, callback, null); latch.await(30, TimeUnit.SECONDS); } @Test public void testMultiSymlink() throws InterruptedException { final CountDownLatch latch = new CountDownLatch(1); AsyncCallback.ChildrenCallback callback = new AsyncCallback.ChildrenCallback() { @Override public void processResult(int rc, String path, Object ctx, List<String> children) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.OK); Assert.assertEquals(path, "/$bar/$link"); Assert.assertEquals(children.size(), 10); latch.countDown(); } }; // symlink: /$bar -> /foo // symlink: /foo/$link -> /foo/bar _zkClient.getZooKeeper().getChildren("/$bar/$link", null, callback, null); latch.await(30, TimeUnit.SECONDS); } @Test public void testSymlinkGetData() throws InterruptedException { final CountDownLatch latch = new CountDownLatch(1); AsyncCallback.DataCallback callback = new AsyncCallback.DataCallback() { @Override public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) { String value = null; try { value = new String(data, "UTF-8"); } catch (UnsupportedEncodingException e) { Assert.fail(e.getMessage()); } finally { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.OK); Assert.assertEquals(value, (String) ctx); Assert.assertNotNull(stat); latch.countDown(); } } }; // symlink: /foo/$link/1 -> /foo/bar/1 _zkClient.getZooKeeper().getData("/foo/$link/1", null, callback, "1"); latch.await(30, TimeUnit.SECONDS); } @Test public void testSymlinkGetChildrenAndData() throws InterruptedException { final CountDownLatch latch = new CountDownLatch(10); AsyncCallback.ChildrenCallback callback = new AsyncCallback.ChildrenCallback() { @Override public void processResult(int rc, String path, Object ctx, List<String> children) { AsyncCallback.DataCallback dataCallback = new AsyncCallback.DataCallback() { @Override public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) { String value = null; try { value = new String(data, "UTF-8"); } catch (UnsupportedEncodingException e) { Assert.fail(e.getMessage()); } finally { Assert.assertEquals(value, (String) ctx); latch.countDown(); } } }; for (String child : children) { _zkClient.getZooKeeper().getData(path + "/" + child, null, dataCallback, child); } } }; _zkClient.getZooKeeper().getChildren("/foo/$link", null, callback, null); latch.await(30, TimeUnit.SECONDS); } @Test public void testNonexistentSymlink() throws ExecutionException, InterruptedException { final CountDownLatch latch = new CountDownLatch(3); AsyncCallback.StatCallback statCallback = new AsyncCallback.StatCallback() { @Override public void processResult(int rc, String path, Object ctx, Stat stat) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.NONODE); latch.countDown(); } }; AsyncCallback.DataCallback dataCallback = new AsyncCallback.DataCallback() { @Override public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.NONODE); latch.countDown(); } }; AsyncCallback.ChildrenCallback childrenCallback = new AsyncCallback.ChildrenCallback() { @Override public void processResult(int rc, String path, Object ctx, List<String> children) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.NONODE); latch.countDown(); } }; // symlink: /foo/$badlink -> null _zkClient.getZooKeeper().exists("/foo/$badlink", false, statCallback, null); _zkClient.getZooKeeper().getData("/foo/$badlink", false, dataCallback, null); _zkClient.getZooKeeper().getChildren("/foo/$badlink", false, childrenCallback, null); latch.await(30, TimeUnit.SECONDS); } @Test public void testSymlinkWithExistWatch() throws InterruptedException, ExecutionException { final CountDownLatch latch = new CountDownLatch(1); final CountDownLatch latch2 = new CountDownLatch(1); final AsyncCallback.StatCallback existCallback = new AsyncCallback.StatCallback() { @Override public void processResult(int rc, String path, Object ctx, Stat stat) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.OK); latch.countDown(); } }; Watcher existWatch = new Watcher() { @Override public void process(WatchedEvent event) { Assert.assertEquals(event.getType(), Event.EventType.NodeCreated); _zkClient.getZooKeeper().exists(event.getPath(), null, existCallback, null); } }; AsyncCallback.StatCallback existCallback2 = new AsyncCallback.StatCallback() { @Override public void processResult(int rc, String path, Object ctx, Stat stat) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.NONODE); latch2.countDown(); } }; // symlink: /foo/$link/newNode -> /foo/bar/newNode _zkClient.getZooKeeper().exists("/foo/$link/newNode", existWatch, existCallback2, null); latch2.await(30, TimeUnit.SECONDS); _zkClient.ensurePersistentNodeExists("/foo/bar/newNode", new FutureCallback<None>()); latch.await(30, TimeUnit.SECONDS); _zkClient.removeNodeUnsafe("/foo/bar/newNode", new FutureCallback<None>()); } @Test public void testSymlinkWithExistWatch2() throws InterruptedException, ExecutionException { final CountDownLatch latch = new CountDownLatch(1); final CountDownLatch latch2 = new CountDownLatch(1); final AsyncCallback.StatCallback existCallback = new AsyncCallback.StatCallback() { @Override public void processResult(int rc, String path, Object ctx, Stat stat) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.OK); latch.countDown(); } }; Watcher existWatch = new Watcher() { @Override public void process(WatchedEvent event) { Assert.assertEquals(event.getType(), Event.EventType.NodeDataChanged); _zkClient.getZooKeeper().exists(event.getPath(), null, existCallback, null); } }; AsyncCallback.StatCallback existCallback2 = new AsyncCallback.StatCallback() { @Override public void processResult(int rc, String path, Object ctx, Stat stat) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.NONODE); latch2.countDown(); } }; // symlink: /foo/$link/foo -> /foo/bar/foo, which doesn't exist _zkClient.getZooKeeper().exists("/foo/$link/foo", existWatch, existCallback2, null); latch2.await(30, TimeUnit.SECONDS); // update symlink. now it points to /bar/foo, which does exist. _zkClient.setSymlinkData("/foo/$link", "/bar", new FutureCallback<None>()); latch.await(30, TimeUnit.SECONDS); // restore symlink _zkClient.setSymlinkData("/foo/$link", "/foo/bar", new FutureCallback<None>()); } @Test public void testSymlinkWithExistWatch3() throws InterruptedException, ExecutionException { final CountDownLatch latch = new CountDownLatch(1); final CountDownLatch latch2 = new CountDownLatch(1); final AsyncCallback.StatCallback existCallback = new AsyncCallback.StatCallback() { @Override public void processResult(int rc, String path, Object ctx, Stat stat) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.OK); latch.countDown(); } }; Watcher existWatch = new Watcher() { @Override public void process(WatchedEvent event) { Assert.assertEquals(event.getType(), Event.EventType.NodeCreated); _zkClient.getZooKeeper().exists(event.getPath(), null, existCallback, null); } }; AsyncCallback.StatCallback existCallback2 = new AsyncCallback.StatCallback() { @Override public void processResult(int rc, String path, Object ctx, Stat stat) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.NONODE); latch2.countDown(); } }; // symlink /$link doesn't exist. _zkClient.getZooKeeper().exists("/$link", existWatch, existCallback2, null); latch2.await(30, TimeUnit.SECONDS); // create symlink /$link -> /foo/bar. existWatch should be notified. _zkClient.createSymlink("/$link", "/foo/bar", new FutureCallback<None>()); latch.await(30, TimeUnit.SECONDS); // delete symlink /$link _zkClient.removeNodeUnsafe("/$link", new FutureCallback<None>()); } @Test public void testSymlinkWithChildrenWatch() throws InterruptedException { final CountDownLatch latch = new CountDownLatch(1); final CountDownLatch latch2 = new CountDownLatch(1); final AsyncCallback.ChildrenCallback childrenCallback = new AsyncCallback.ChildrenCallback() { @Override public void processResult(int rc, String path, Object ctx, List<String> children) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.OK); Assert.assertEquals(children.size(), 11); latch.countDown(); } }; Watcher childrenWatch = new Watcher() { @Override public void process(WatchedEvent event) { Assert.assertEquals(event.getType(), Event.EventType.NodeChildrenChanged); _zkClient.getZooKeeper().getChildren(event.getPath(), null, childrenCallback, null); } }; AsyncCallback.ChildrenCallback childrenCallback2 = new AsyncCallback.ChildrenCallback() { @Override public void processResult(int rc, String path, Object ctx, List<String> children) { KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.OK); latch2.countDown(); } }; // symlink: /foo/$link -> /foo/bar _zkClient.getZooKeeper().getChildren("/foo/$link", childrenWatch, childrenCallback2, null); latch2.await(30, TimeUnit.SECONDS); _zkClient.ensurePersistentNodeExists("/foo/bar/newNode", new FutureCallback<None>()); latch.await(30, TimeUnit.SECONDS); _zkClient.removeNodeUnsafe("/foo/bar/newNode", new FutureCallback<None>()); } @Test public void testSymlinkWithChildrenWatcher2() throws ExecutionException, InterruptedException { final CountDownLatch latch1 = new CountDownLatch(1); final CountDownLatch latch2 = new CountDownLatch(1); final AsyncCallback.ChildrenCallback callback2 = new AsyncCallback.ChildrenCallback() { @Override public void processResult(int rc, String path, Object ctx, List<String> children) { Assert.assertEquals(path, "/foo/$link"); Assert.assertEquals(children.size(), 5); latch2.countDown(); } }; Watcher watcher = new Watcher() { @Override public void process(WatchedEvent event) { Assert.assertEquals(event.getType(), Event.EventType.NodeChildrenChanged); _zkClient.getZooKeeper().getChildren(event.getPath(), null, callback2, null); } }; AsyncCallback.ChildrenCallback callback = new AsyncCallback.ChildrenCallback() { @Override public void processResult(int rc, String path, Object ctx, List<String> children) { latch1.countDown(); } }; // set watcher to /foo/$link _zkClient.getZooKeeper().getChildren("/foo/$link", watcher, callback, null); latch1.await(30, TimeUnit.SECONDS); // update symlink _zkClient.setSymlinkData("/foo/$link", "/bar/foo", new FutureCallback<None>()); latch2.await(30, TimeUnit.SECONDS); FutureCallback<None> fcb = new FutureCallback<None>(); // restore symlink _zkClient.setSymlinkData("/foo/$link", "/foo/bar", fcb); fcb.get(); } // test children2Callback watcher @Test public void testSymlinkWithChildrenWatcher3() throws ExecutionException, InterruptedException, KeeperException { final CountDownLatch latch1 = new CountDownLatch(1); final CountDownLatch latch2 = new CountDownLatch(1); Stat expectedStat1 = _zkClient.getZooKeeper().exists("/foo/bar", false); Stat expectedStat2 = _zkClient.getZooKeeper().exists("/bar/foo", false); final AsyncCallback.Children2Callback callback2 = new AsyncCallback.Children2Callback() { @Override public void processResult(int rc, String path, Object ctx, List<String> children, Stat stat) { Assert.assertEquals(path, "/foo/$link"); Assert.assertEquals(children.size(), 5); Assert.assertEquals(stat, expectedStat2); latch2.countDown(); } }; Watcher watcher = new Watcher() { @Override public void process(WatchedEvent event) { Assert.assertEquals(event.getType(), Event.EventType.NodeChildrenChanged); _zkClient.getZooKeeper().getChildren(event.getPath(), null, callback2, null); } }; AsyncCallback.Children2Callback callback = new AsyncCallback.Children2Callback() { @Override public void processResult(int rc, String path, Object ctx, List<String> children, Stat stat) { Assert.assertEquals(stat, expectedStat1); latch1.countDown(); } }; // set watcher to /foo/$link _zkClient.getZooKeeper().getChildren("/foo/$link", watcher, callback, null); latch1.await(30, TimeUnit.SECONDS); // update symlink _zkClient.setSymlinkData("/foo/$link", "/bar/foo", new FutureCallback<None>()); latch2.await(30, TimeUnit.SECONDS); FutureCallback<None> fcb = new FutureCallback<None>(); // restore symlink _zkClient.setSymlinkData("/foo/$link", "/foo/bar", fcb); fcb.get(); } @Test public void testInvalidSymlinkWithExists() throws ExecutionException, InterruptedException { final CountDownLatch latch1 = new CountDownLatch(1); final CountDownLatch latch2 = new CountDownLatch(1); final AsyncCallback.StatCallback callback = new AsyncCallback.StatCallback() { @Override public void processResult(int rc, String path, Object ctx, Stat stat) { Assert.assertEquals(path, "/foo/$link"); KeeperException.Code result = KeeperException.Code.get(rc); Assert.assertEquals(result, KeeperException.Code.NONODE); latch1.countDown(); } }; final Watcher watcher = new Watcher() { @Override public void process(WatchedEvent event) { Assert.assertEquals(event.getType(), Event.EventType.NodeDataChanged); latch2.countDown(); } }; FutureCallback<None> fcb = new FutureCallback<None>(); _zkClient.setSymlinkData("/foo/$link", "INVALID", fcb); fcb.get(); _zkClient.getZooKeeper().exists("/foo/$link", watcher, callback, null); latch1.await(30, TimeUnit.SECONDS); _zkClient.setSymlinkData("/foo/$link", "/foo/bar", fcb); if (!latch2.await(30, TimeUnit.SECONDS)) { Assert.fail("Exists Watch is not triggered"); } } }