| package org.apache.helix.util; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.util.Map; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| import org.apache.helix.manager.zk.ZNRecordSerializer; |
| import org.apache.helix.manager.zk.ZkClient; |
| import org.apache.zookeeper.ZooKeeper.States; |
| |
| public class ZKClientPool { |
| static final Map<String, ZkClient> _zkClientMap = new ConcurrentHashMap<>(); |
| static final int DEFAULT_SESSION_TIMEOUT = 30 * 1000; |
| |
| public static ZkClient getZkClient(String zkServer) { |
| // happy path that we cache the zkclient and it's still connected |
| if (_zkClientMap.containsKey(zkServer)) { |
| ZkClient zkClient = _zkClientMap.get(zkServer); |
| if (zkClient.getConnection().getZookeeperState() == States.CONNECTED) { |
| return zkClient; |
| } |
| } |
| |
| synchronized (_zkClientMap) { |
| // if we cache a stale zkclient, purge it |
| if (_zkClientMap.containsKey(zkServer)) { |
| ZkClient zkClient = _zkClientMap.get(zkServer); |
| if (zkClient.getConnection().getZookeeperState() != States.CONNECTED) { |
| _zkClientMap.remove(zkServer); |
| } |
| } |
| |
| // get a new zkclient |
| if (!_zkClientMap.containsKey(zkServer)) { |
| ZkClient zkClient = |
| new ZkClient(zkServer, DEFAULT_SESSION_TIMEOUT, ZkClient.DEFAULT_CONNECTION_TIMEOUT, |
| new ZNRecordSerializer()); |
| |
| _zkClientMap.put(zkServer, zkClient); |
| } |
| return _zkClientMap.get(zkServer); |
| } |
| } |
| |
| public static void reset() { |
| _zkClientMap.clear(); |
| } |
| |
| public static void main(String[] args) throws InterruptedException { |
| Thread /* |
| * _dataSampleThread = new Thread(new Runnable() |
| * { |
| * @Override |
| * public void run() |
| * { |
| * int i = 0; |
| * while(!Thread.currentThread().isInterrupted()) |
| * { |
| * try |
| * { |
| * // if the queue is empty, sleep 100 ms and try again |
| * Thread.sleep(1000); |
| * System.out.println(i++ + "..."); |
| * throw new RuntimeException("" + i); |
| * } |
| * catch (InterruptedException e) |
| * { |
| * System.out.println("Collector thread interrupted" + e); |
| * return; |
| * } |
| * catch(Throwable th) |
| * { |
| * System.out.println("Collector thread exception/ error" + th); |
| * } |
| * } |
| * } |
| * }); |
| * _dataSampleThread.start(); |
| * Thread.sleep(10000); |
| * _dataSampleThread.interrupt(); |
| */ |
| _dataSampleThread = new Thread(new Runnable() { |
| @Override |
| public void run() { |
| int i = 0; |
| while (!Thread.currentThread().isInterrupted()) { |
| |
| // if the queue is empty, sleep 100 ms and try again |
| try { |
| Thread.sleep(1000); |
| } catch (InterruptedException e) { |
| // TODO Auto-generated catch block |
| e.printStackTrace(); |
| } |
| System.out.println(i++ + "..."); |
| throw new Error("" + i); |
| |
| } |
| } |
| }); |
| _dataSampleThread.start(); |
| |
| Thread.sleep(10000); |
| _dataSampleThread.interrupt(); |
| } |
| } |