com.cc.zk.common.ZkStateReader.java Source code

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Here is the source code for com.cc.zk.common.ZkStateReader.java

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package com.cc.zk.common;

/*
 * 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.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.EventType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ZkStateReader {
    private static Logger log = LoggerFactory.getLogger(ZkStateReader.class);

    public static final String LIVE_NODES_ZKNODE = "/ce_live_nodes";
    public static final String SERVICE_ZKNODE = "/service";
    public static final String ESCLIENT = "esclient";
    public static final String AGENT = "agent";
    public static final String REDIS = "redis";
    public static final String FTP_SERVER = "ftp_server";
    public static final String FTP_MONITOR = "ftp_monitor";
    public static final String WEB_MONITOR = "web_monitor";

    //private volatile ClusterState clusterState;

    //public static final String CLUSTER_STATE = "/ce_clusterstate.json";

    public static final String ACTIVE = "active";
    public static final String DOWN = "down";
    public static final String SYNC = "sync";

    public static final int ZKCLIENTTIMEOUT = 15000;
    public static final int ZKCLIENTCONNECTTIMEOUT = 15000;

    public static final String ZKURL = "zkUrl";

    //private final Map<String,Set<String>> clusterMap=new HashMap<String, Set<String>>();

    private final Set<String> liveNodes = new HashSet<String>();

    private ZkClient zkClient;

    private boolean closeClient = false;

    private ZkCmdExecutor cmdExecutor;

    private volatile boolean closed = false;

    public ZkStateReader(ZkClient zkClient) {
        this.zkClient = zkClient;
        initZkCmdExecutor(zkClient.getZkClientTimeout());
    }

    private void initZkCmdExecutor(int zkClientTimeout) {
        // we must retry at least as long as the session timeout
        cmdExecutor = new ZkCmdExecutor(zkClientTimeout);
    }

    public Object getUpdateLock() {
        return this;
    }

    public void close() {
        this.closed = true;
        if (closeClient) {
            zkClient.close();
        }
    }

    abstract class RunnableWatcher implements Runnable {
        Watcher watcher;

        public RunnableWatcher(Watcher watcher) {
            this.watcher = watcher;
        }

    }

    public ZkClient getZkClient() {
        return zkClient;
    }

    /**
     * TODO ??
     * @throws KeeperException
     * @throws InterruptedException
     */
    public void getRemoteLiveNodes() throws KeeperException, InterruptedException {
        List<String> nodes = zkClient.getChildren(ZkStateReader.LIVE_NODES_ZKNODE, new Watcher() {

            @Override
            public void process(WatchedEvent event) {
                // session events are not change events,
                // and do not remove the watcher
                if (EventType.None.equals(event.getType())) {
                    return;
                }
                try {
                    System.out.println("ZkStateReader.getLiveNodes().new Watcher() {...}.process()----------");
                    synchronized (ZkStateReader.this.getUpdateLock()) {
                        List<String> nodes = zkClient.getChildren(LIVE_NODES_ZKNODE, this, true);

                        ZkStateReader.this.liveNodes.addAll(nodes);

                    }
                } catch (KeeperException e) {
                    if (e.code() == KeeperException.Code.SESSIONEXPIRED
                            || e.code() == KeeperException.Code.CONNECTIONLOSS) {
                        log.warn("ZooKeeper watch triggered, but Solr cannot talk to ZK");
                        return;
                    }
                    log.error("", e);
                    throw new ZooKeeperException(CeException.ErrorCode.SERVER_ERROR, "", e);
                } catch (InterruptedException e) {
                    // Restore the interrupted status
                    Thread.currentThread().interrupt();
                    log.warn("", e);
                    return;
                }
            }

        }, true);

        ZkStateReader.this.liveNodes.addAll(nodes);

    }

    public Set<String> getLiveNodes() {
        return Collections.unmodifiableSet(liveNodes);
    }
}