/*
* 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.twill.internal.state;
import com.google.common.base.Charsets;
import com.google.common.base.Joiner;
import com.google.common.base.Preconditions;
import com.google.common.base.Suppliers;
import com.google.common.util.concurrent.AbstractIdleService;
import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.Service;
import com.google.gson.Gson;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import org.apache.twill.api.RunId;
import org.apache.twill.internal.RunIds;
import org.apache.twill.internal.ZKServiceDecorator;
import org.apache.twill.internal.zookeeper.InMemoryZKServer;
import org.apache.twill.zookeeper.NodeData;
import org.apache.twill.zookeeper.ZKClientService;
import org.apache.twill.zookeeper.ZKClients;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.data.Stat;
import org.junit.Assert;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicReference;
/**
*
*/
public class ZKServiceDecoratorTest {
private static final Logger LOG = LoggerFactory.getLogger(ZKServiceDecoratorTest.class);
@Test
public void testStateTransition() throws InterruptedException, ExecutionException, TimeoutException {
InMemoryZKServer zkServer = InMemoryZKServer.builder().build();
zkServer.startAndWait();
try {
final String namespace = Joiner.on('/').join("/twill", RunIds.generate(), "runnables", "Runner1");
final ZKClientService zkClient = ZKClientService.Builder.of(zkServer.getConnectionStr()).build();
zkClient.startAndWait();
zkClient.create(namespace, null, CreateMode.PERSISTENT).get();
try {
JsonObject content = new JsonObject();
content.addProperty("containerId", "container-123");
content.addProperty("host", "localhost");
RunId runId = RunIds.generate();
final Semaphore semaphore = new Semaphore(0);
ZKServiceDecorator service = new ZKServiceDecorator(ZKClients.namespace(zkClient, namespace),
runId, Suppliers.ofInstance(content),
new AbstractIdleService() {
@Override
protected void startUp() throws Exception {
Preconditions.checkArgument(semaphore.tryAcquire(5, TimeUnit.SECONDS), "Fail to start");
}
@Override
protected void shutDown() throws Exception {
Preconditions.checkArgument(semaphore.tryAcquire(5, TimeUnit.SECONDS), "Fail to stop");
}
});
final String runnablePath = namespace + "/" + runId.getId();
final AtomicReference<String> stateMatch = new AtomicReference<String>("STARTING");
watchDataChange(zkClient, runnablePath + "/state", semaphore, stateMatch);
Assert.assertEquals(Service.State.RUNNING, service.start().get(5, TimeUnit.SECONDS));
stateMatch.set("STOPPING");
Assert.assertEquals(Service.State.TERMINATED, service.stop().get(5, TimeUnit.SECONDS));
} finally {
zkClient.stopAndWait();
}
} finally {
zkServer.stopAndWait();
}
}
private void watchDataChange(final ZKClientService zkClient, final String path,
final Semaphore semaphore, final AtomicReference<String> stateMatch) {
Futures.addCallback(zkClient.getData(path, new Watcher() {
@Override
public void process(WatchedEvent event) {
if (event.getType() == Event.EventType.NodeDataChanged) {
watchDataChange(zkClient, path, semaphore, stateMatch);
}
}
}), new FutureCallback<NodeData>() {
@Override
public void onSuccess(NodeData result) {
String content = new String(result.getData(), Charsets.UTF_8);
JsonObject json = new Gson().fromJson(content, JsonElement.class).getAsJsonObject();
if (stateMatch.get().equals(json.get("state").getAsString())) {
semaphore.release();
}
}
@Override
public void onFailure(Throwable t) {
exists();
}
private void exists() {
Futures.addCallback(zkClient.exists(path, new Watcher() {
@Override
public void process(WatchedEvent event) {
if (event.getType() == Event.EventType.NodeCreated) {
watchDataChange(zkClient, path, semaphore, stateMatch);
}
}
}), new FutureCallback<Stat>() {
@Override
public void onSuccess(Stat result) {
if (result != null) {
watchDataChange(zkClient, path, semaphore, stateMatch);
}
}
@Override
public void onFailure(Throwable t) {
LOG.error(t.getMessage(), t);
}
});
}
});
}
}