com.alibaba.otter.shared.arbitrate.impl.zookeeper.ZooKeeperx Maven / Gradle / Ivy
/*
* Copyright (C) 2010-2101 Alibaba Group Holding Limited.
*
* 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.alibaba.otter.shared.arbitrate.impl.zookeeper;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.AsyncCallback.VoidCallback;
import org.apache.zookeeper.data.ACL;
import org.apache.zookeeper.data.Stat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.alibaba.otter.shared.arbitrate.exception.ArbitrateException;
/**
* 扩展ZooKeeper，主要是统一处理下链接异常和ACL管理
*
* document :
* http://wiki.apache. org/hadoop/ZooKeeper/FAQ#A3
* http://wiki.apache.org/hadoop/ZooKeeper/ErrorHandling
*
* @author jianghang 2011-9-23 下午01:38:06
* @version 4.0.0
*/
@Deprecated
public class ZooKeeperx {
private static final Logger logger = LoggerFactory.getLogger(ZooKeeperx.class);
// private static final Field zooKeeperField = ReflectionUtils.findField(ZooKeeperClient.class, "zookeeper");
private static final Integer maxRetry = 3; // 出现exception，最多重试3次
private long retryDelay = 3000L;
private List acl = ZooDefs.Ids.OPEN_ACL_UNSAFE;
private ZooKeeper zookeeper;
private AtomicInteger cversion = new AtomicInteger(0);
private AtomicBoolean running = new AtomicBoolean(true);
public ZooKeeperx(ZooKeeper zookeeper){
this.zookeeper = zookeeper;
}
/**
* add by ljh at 2012-09-13
*
*
* 1. 使用zookeeper过程，针对出现ConnectionLoss异常，比如进行create/setData/delete，操作可能已经在zookeeper server上进行应用
* 2. 针对SelectStageListener进行processId创建时，会以最后一次创建的processId做为调度id. 如果进行retry，之前成功的processId就会被遗漏了
*
*
* @see org.apache.zookeeper.ZooKeeper#create(String path, byte[] path, List acl, CreateMode mode)
*/
public String createNoRetry(final String path, final byte[] data, final CreateMode mode) throws KeeperException,
InterruptedException {
return zookeeper.create(path, data, acl, mode);
}
/**
*
* 1. 使用zookeeper过程，针对出现ConnectionLoss异常，比如进行create/setData/delete，操作可能已经在zookeeper server上进行应用
* 2. 针对SelectStageListener进行processId创建时，会以最后一次创建的processId做为调度id. 如果进行retry，之前成功的processId就会被遗漏了
*
*
* @see org.apache.zookeeper.ZooKeeper#create(String path, byte[] path, List acl, CreateMode mode)
*/
public String create(final String path, final byte[] data, final CreateMode mode) throws KeeperException,
InterruptedException {
if (mode.isSequential()) {
return zookeeper.create(path, data, acl, mode);
} else {
return retryOperation(new ZooKeeperOperation() {
public String execute() throws KeeperException, InterruptedException {
return zookeeper.create(path, data, acl, mode);
}
});
}
}
/**
* @see org.apache.zookeeper.ZooKeeper#delete(String path, int version)
*/
public void delete(final String path, final int version) throws InterruptedException, KeeperException {
retryOperation(new ZooKeeperOperation() {
public Object execute() throws KeeperException, InterruptedException {
zookeeper.delete(path, version);
return null;
}
});
}
/**
* @see org.apache.zookeeper.ZooKeeper#delete(String path, int version , VoidCallback cb , Object ctx)
*/
public void delete(final String path, final int version, final VoidCallback cb, final Object ctx)
throws InterruptedException,
KeeperException {
retryOperation(new ZooKeeperOperation() {
public Object execute() throws KeeperException, InterruptedException {
zookeeper.delete(path, version, cb, ctx);
return null;
}
});
}
/**
* @see org.apache.zookeeper.ZooKeeper#exists(String path, boolean watch)
*/
public Stat exists(final String path, final boolean watch) throws KeeperException, InterruptedException {
return retryOperation(new ZooKeeperOperation() {
public Stat execute() throws KeeperException, InterruptedException {
return zookeeper.exists(path, watch);
}
});
}
/**
* @see org.apache.zookeeper.ZooKeeper#exists(String path, Watcher watcher)
*/
public Stat exists(final String path, final Watcher watcher) throws KeeperException, InterruptedException {
return retryOperation(new ZooKeeperOperation() {
public Stat execute() throws KeeperException, InterruptedException {
return zookeeper.exists(path, watcher);
}
});
}
/**
* @see org.apache.zookeeper.ZooKeeper#getChildren(String path, boolean watch)
*/
public List getChildren(final String path, final boolean watch) throws KeeperException,
InterruptedException {
return retryOperation(new ZooKeeperOperation>() {
public List execute() throws KeeperException, InterruptedException {
return zookeeper.getChildren(path, watch);
}
});
}
/**
* @see org.apache.zookeeper.ZooKeeper#getChildren(String path, boolean watch , Stat stat)
*/
public List getChildren(final String path, final boolean watch, final Stat stat) throws KeeperException,
InterruptedException {
return retryOperation(new ZooKeeperOperation>() {
public List execute() throws KeeperException, InterruptedException {
return zookeeper.getChildren(path, watch, stat);
}
});
}
/**
* @see org.apache.zookeeper.ZooKeeper#getChildren(String path, Watcher watcher)
*/
public List getChildren(final String path, final Watcher watcher) throws KeeperException,
InterruptedException {
return retryOperation(new ZooKeeperOperation>() {
public List execute() throws KeeperException, InterruptedException {
return zookeeper.getChildren(path, watcher);
}
});
}
/**
* @see org.apache.zookeeper.ZooKeeper#getData(String path, boolean watch, Stat stat)
*/
public byte[] getData(final String path, final boolean watch, final Stat stat) throws KeeperException,
InterruptedException {
return retryOperation(new ZooKeeperOperation() {
public byte[] execute() throws KeeperException, InterruptedException {
return zookeeper.getData(path, watch, stat);
}
});
}
/**
* @see org.apache.zookeeper.ZooKeeper#getData(String path, Watcher watcher, Stat stat)
*/
public byte[] getData(final String path, final Watcher watcher, final Stat stat) throws KeeperException,
InterruptedException {
return retryOperation(new ZooKeeperOperation() {
public byte[] execute() throws KeeperException, InterruptedException {
return zookeeper.getData(path, watcher, stat);
}
});
}
/**
* @see org.apache.zookeeper.ZooKeeper#setData(String path, byte[] data, int version)
*/
public Stat setData(final String path, final byte[] data, final int version) throws KeeperException,
InterruptedException {
return retryOperation(new ZooKeeperOperation() {
public Stat execute() throws KeeperException, InterruptedException {
return zookeeper.setData(path, data, version);
}
});
}
// =========================== helper method =============================
/**
* 包装重试策略
*/
public T retryOperation(ZooKeeperOperation operation) throws KeeperException, InterruptedException {
if (!running.get()) {
throw new ArbitrateException("Zookeeper is destory ,should never be used ....");
}
KeeperException exception = null;
for (int i = 0; i < maxRetry; i++) {
int version = cversion.get(); // 获取版本
int retryCount = i + 1;
try {
if (!zookeeper.getState().isAlive()) {
retryDelay(retryCount);
cleanup(version);
} else {
return (T) operation.execute();
}
} catch (KeeperException.SessionExpiredException e) {
logger.warn("Session expired for: " + this + " so reconnecting " + (i + 1) + " times due to: " + e, e);
retryDelay(retryCount);
cleanup(version);
} catch (KeeperException.ConnectionLossException e) { // 特殊处理Connection Loss
if (exception == null) {
exception = e;
}
logger.warn("Attempt " + retryCount + " failed with connection loss so " + "attempting to reconnect: "
+ e, e);
retryDelay(retryCount);
}
}
throw exception;
}
private void retryDelay(int attemptCount) {
if (attemptCount > 0) {
try {
Thread.sleep(attemptCount * retryDelay);
} catch (InterruptedException e) {
logger.warn("Failed to sleep: " + e, e);
}
}
}
public ZooKeeper getDelegate() {
return this.zookeeper;
}
private synchronized void cleanup(int version) { // 加锁操作，阻塞等待上一次的重建完成
// if (cversion.compareAndSet(version, version + 1)) {// 看一下version是否有变化，没变化就我来更新
// // ReflectionUtils.makeAccessible(zooKeeperField);
// // ReflectionUtils.setField(zooKeeperField, new ZooKeeperClient(), null);// 清空
// ZooKeeper oldZookeepre = zookeeper;
// zookeeper = ZooKeeperClient.createZookeeper();
//
// try {
// oldZookeepre.close(); // 关闭老链接
// } catch (InterruptedException e) {
// // ignore
// }
// for (SessionExpiredNotification notification : ZooKeeperClient.getNotifications()) {
// notification.notification(this);
// }
//
// cversion.incrementAndGet();// 更新一下版本号
// } else {
// // 更新失败，忽略。说明已经有别的线程重建过zookeeper，再做一次尝试
// }
}
public void destory() {
if (running.compareAndSet(true, false)) {
try {
zookeeper.close();
} catch (InterruptedException e) {
// ignore
}
}
}
// ===================== setter / getter =================
public List getAcl() {
return acl;
}
public void setAcl(List acl) {
this.acl = acl;
}
public long getRetryDelay() {
return retryDelay;
}
public void setRetryDelay(long retryDelay) {
this.retryDelay = retryDelay;
}
}