/*-
* -\-\-
* Helios Services
* --
* Copyright (C) 2016 Spotify AB
* --
* 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.spotify.helios.servicescommon;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;
import static org.apache.curator.framework.state.ConnectionState.RECONNECTED;
import static org.hamcrest.Matchers.both;
import static org.hamcrest.Matchers.greaterThanOrEqualTo;
import static org.hamcrest.Matchers.lessThanOrEqualTo;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
import static org.mockito.Matchers.longThat;
import static org.mockito.Mockito.doNothing;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;
import com.google.common.util.concurrent.SettableFuture;
import com.spotify.helios.agent.BoundedRandomExponentialBackoff;
import com.spotify.helios.agent.RetryIntervalPolicy;
import com.spotify.helios.agent.Sleeper;
import com.spotify.helios.master.HostNotFoundException;
import com.spotify.helios.servicescommon.coordination.ZooKeeperClient;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.listen.Listenable;
import org.apache.curator.framework.state.ConnectionStateListener;
import org.apache.zookeeper.KeeperException;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.ArgumentCaptor;
import org.mockito.Captor;
import org.mockito.Mock;
import org.mockito.runners.MockitoJUnitRunner;
@RunWith(MockitoJUnitRunner.class)
public class ZooKeeperRegistrarServiceTest {
@Mock private ZooKeeperClient zkClient;
@Mock private Listenable<ConnectionStateListener> connectionStateListenerListenable;
@Mock private Sleeper sleeper;
@Captor private ArgumentCaptor<ConnectionStateListener> zkClientConnectionListenerCaptor;
private SettableFuture<Void> complete = SettableFuture.create();
private final SettableFuture<Void> shutdownComplete = SettableFuture.create();
private final RetryIntervalPolicy retryIntervalPolicy =
BoundedRandomExponentialBackoff.newBuilder()
.setMinInterval(1, MILLISECONDS)
.setMaxInterval(30, MILLISECONDS)
.build();
@Before
public void setup() {
when(zkClient.getConnectionStateListenable()).thenReturn(connectionStateListenerListenable);
doNothing().when(connectionStateListenerListenable)
.addListener(zkClientConnectionListenerCaptor.capture());
}
/**
* Creates a new ZooKeeperRegistrar that completes {@link #complete} when tryToRegister is
* called and {@link #shutdownComplete} when shutDown is called..
*
* @param registered what the return value from
* {@link ZooKeeperRegistrar#tryToRegister(ZooKeeperClient)} should be
*/
private ZooKeeperRegistrar createStubRegistrar(boolean registered) {
return createStubRegistrar(registered, client -> { });
}
/**
* An overload of {@link #createStubRegistrar(boolean)} which invokes the Consumer in
* tryToRegister before completing {@link #complete}. This can be used to customize the behavior
* of tryToRegister without having to declare yet another subclass of ZooKeeperRegistrar.
*/
private ZooKeeperRegistrar createStubRegistrar(
boolean registered, ClientConsumer clientConsumer) {
return new ZooKeeperRegistrar() {
@Override
public void startUp() throws Exception {
}
@Override
public void shutDown() throws Exception {
shutdownComplete.set(null);
}
@Override
public boolean tryToRegister(ZooKeeperClient client)
throws KeeperException, HostNotFoundException {
clientConsumer.accept(client);
complete.set(null);
return registered;
}
};
}
// Would just use Consumer<ZooKeeperClient> but Consumer does not throw checked exceptions
@FunctionalInterface
private interface ClientConsumer {
void accept(ZooKeeperClient client) throws KeeperException, HostNotFoundException;
}
@Test
public void testAllGood() throws Exception {
final ZooKeeperRegistrar zooKeeperRegistrar = createStubRegistrar(true);
final CountDownLatch latch = new CountDownLatch(1);
final ZooKeeperRegistrarService init = ZooKeeperRegistrarService.newBuilder()
.setZooKeeperClient(zkClient)
.setZooKeeperRegistrar(zooKeeperRegistrar)
.setZkRegistrationSignal(latch)
.build();
init.startUp();
assertNull(complete.get(3000, MILLISECONDS));
// need to wait on latch rather than just check the count as the decrement might happen after
// the test thread has woken up when the SettableFuture is set
final boolean latchCleared = latch.await(3, SECONDS);
assertTrue("Latch should be open after successful registration", latchCleared);
}
@Test
public void testShutdown() throws Exception {
final ZooKeeperRegistrar zooKeeperRegistrar = createStubRegistrar(true);
final ZooKeeperRegistrarService init = ZooKeeperRegistrarService.newBuilder()
.setZooKeeperClient(zkClient)
.setZooKeeperRegistrar(zooKeeperRegistrar)
.build();
init.startUp();
assertNull(complete.get(3000, MILLISECONDS));
// if this throws exception something is bonkers
init.shutDown();
assertNull(shutdownComplete.get(3000, MILLISECONDS));
}
@Test
public void testRetry() throws Exception {
final AtomicInteger counter = new AtomicInteger(0);
final ZooKeeperRegistrar zooKeeperRegistrar = createStubRegistrar(true, client -> {
final int count = counter.incrementAndGet();
if (count == 1) {
throw new KeeperException.ConnectionLossException();
}
if (count == 2) {
throw new HostNotFoundException("Host not found");
}
});
final ZooKeeperRegistrarService init = ZooKeeperRegistrarService.newBuilder()
.setZooKeeperClient(zkClient)
.setZooKeeperRegistrar(zooKeeperRegistrar)
.setRetryIntervalPolicy(retryIntervalPolicy)
.setSleeper(sleeper)
.build();
init.startUp();
assertNull(complete.get(30, SECONDS));
assertTrue("Count must have been called at least once", counter.get() > 1);
verify(sleeper, times(2))
.sleep(longThat(both(greaterThanOrEqualTo(1L)).and(lessThanOrEqualTo(30L))));
}
@Test
public void testReconnect() throws Exception {
final AtomicInteger counter = new AtomicInteger(0);
final ZooKeeperRegistrar zooKeeperRegistrar =
createStubRegistrar(true, client -> counter.incrementAndGet());
final ZooKeeperRegistrarService init = ZooKeeperRegistrarService.newBuilder()
.setZooKeeperClient(zkClient)
.setZooKeeperRegistrar(zooKeeperRegistrar)
.setRetryIntervalPolicy(retryIntervalPolicy)
.build();
init.startUp();
assertNull(complete.get(30, SECONDS));
// simulate the reconnect
complete = SettableFuture.create();
final CuratorFramework curatorFramework = mock(CuratorFramework.class);
zkClientConnectionListenerCaptor.getValue().stateChanged(curatorFramework, RECONNECTED);
assertNull(complete.get(30, SECONDS));
assertTrue("Count must have been called at least once", counter.get() > 1);
}
@Test
public void testLatchNotSignalledOnRegistrationConflict() throws Exception {
final ZooKeeperRegistrar zooKeeperRegistrar = createStubRegistrar(false);
final int initialCount = 1;
final CountDownLatch latch = new CountDownLatch(initialCount);
final ZooKeeperRegistrarService init = ZooKeeperRegistrarService.newBuilder()
.setZkRegistrationSignal(latch)
.setZooKeeperClient(zkClient)
.setZooKeeperRegistrar(zooKeeperRegistrar)
.setRetryIntervalPolicy(retryIntervalPolicy)
.build();
init.startUp();
//wait for completion
assertNull(complete.get(3000, MILLISECONDS));
assertEquals("Latch should not be counted down if registration did not complete",
initialCount, latch.getCount());
}
}