org.apache.dubbo.registry.dubbo.DubboRegistry Maven / Gradle / Ivy
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* 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.dubbo.registry.dubbo;
import org.apache.dubbo.common.URL;
import org.apache.dubbo.common.Version;
import org.apache.dubbo.common.utils.ExecutorUtil;
import org.apache.dubbo.common.utils.NamedThreadFactory;
import org.apache.dubbo.common.utils.NetUtils;
import org.apache.dubbo.registry.NotifyListener;
import org.apache.dubbo.registry.RegistryService;
import org.apache.dubbo.registry.support.FailbackRegistry;
import org.apache.dubbo.remoting.Constants;
import org.apache.dubbo.rpc.Invoker;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReentrantLock;
import static org.apache.dubbo.registry.Constants.REGISTRY_RECONNECT_PERIOD_KEY;
/**
* DubboRegistry
*/
public class DubboRegistry extends FailbackRegistry {
// Reconnecting detection cycle: 3 seconds (unit:millisecond)
private static final int RECONNECT_PERIOD_DEFAULT = 3 * 1000;
// Scheduled executor service
private final ScheduledExecutorService reconnectTimer = Executors.newScheduledThreadPool(1, new NamedThreadFactory("DubboRegistryReconnectTimer", true));
// Reconnection timer, regular check connection is available. If unavailable, unlimited reconnection.
private final ScheduledFuture reconnectFuture;
// The lock for client acquisition process, lock the creation process of the client instance to prevent repeated clients
private final ReentrantLock clientLock = new ReentrantLock();
private final Invoker registryInvoker;
private final RegistryService registryService;
/**
* The time in milliseconds the reconnectTimer will wait
*/
private final int reconnectPeriod;
public DubboRegistry(Invoker registryInvoker, RegistryService registryService) {
super(registryInvoker.getUrl());
this.registryInvoker = registryInvoker;
this.registryService = registryService;
// Start reconnection timer
this.reconnectPeriod = registryInvoker.getUrl().getParameter(REGISTRY_RECONNECT_PERIOD_KEY, RECONNECT_PERIOD_DEFAULT);
reconnectFuture = reconnectTimer.scheduleWithFixedDelay(() -> {
// Check and connect to the registry
try {
connect();
} catch (Throwable t) { // Defensive fault tolerance
logger.error("Unexpected error occur at reconnect, cause: " + t.getMessage(), t);
}
}, reconnectPeriod, reconnectPeriod, TimeUnit.MILLISECONDS);
}
protected final void connect() {
try {
// Check whether or not it is connected
if (isAvailable()) {
return;
}
if (logger.isInfoEnabled()) {
logger.info("Reconnect to registry " + getUrl());
}
clientLock.lock();
try {
// Double check whether or not it is connected
if (isAvailable()) {
return;
}
recover();
} finally {
clientLock.unlock();
}
} catch (Throwable t) { // Ignore all the exceptions and wait for the next retry
if (getUrl().getParameter(Constants.CHECK_KEY, true)) {
if (t instanceof RuntimeException) {
throw (RuntimeException) t;
}
throw new RuntimeException(t.getMessage(), t);
}
logger.error("Failed to connect to registry " + getUrl().getAddress() + " from provider/consumer " + NetUtils.getLocalHost() + " use dubbo " + Version.getVersion() + ", cause: " + t.getMessage(), t);
}
}
@Override
public boolean isAvailable() {
if (registryInvoker == null) {
return false;
}
return registryInvoker.isAvailable();
}
@Override
public void destroy() {
super.destroy();
try {
// Cancel the reconnection timer
ExecutorUtil.cancelScheduledFuture(reconnectFuture);
} catch (Throwable t) {
logger.warn("Failed to cancel reconnect timer", t);
}
registryInvoker.destroy();
ExecutorUtil.gracefulShutdown(reconnectTimer, reconnectPeriod);
}
@Override
public void doRegister(URL url) {
registryService.register(url);
}
@Override
public void doUnregister(URL url) {
registryService.unregister(url);
}
@Override
public void doSubscribe(URL url, NotifyListener listener) {
registryService.subscribe(url, listener);
}
@Override
public void doUnsubscribe(URL url, NotifyListener listener) {
registryService.unsubscribe(url, listener);
}
@Override
public List lookup(URL url) {
return registryService.lookup(url);
}
}