通过TelnetClient获取Zookeeper监控数据

如果想编写一个监控Zookeeper的Java程序，可以通过两种方式 :

（1）通过TelnetClient发送命令 ,命令的详解参考：http://zookeeper.apache.org/doc/trunk/zookeeperAdmin.html#sc_zkCommands

（2）通过JMX，说明请参考：http://zookeeper.apache.org/doc/trunk/zookeeperJMX.html

本文通过一个简单的例子来演示如何通过TelnetClient发送mntr命令获取Zookeeper的监控数据

写一个Telnet的工具类

package com.eric.agent.utils;import org.apache.commons.net.telnet.TelnetClient;import java.io.IOException;import java.io.InputStream;import java.io.PrintStream;/** * Telnet操作器,基于commons-net-2.2.jar * * @author aihua.sun * @date 2015/4/9 * @since V1.0 */public class TelnetTools {    private String prompt = ">"; //结束标识字符串,Windows中是>,Linux中是#    private char promptChar = '>';   //结束标识字符    private TelnetClient telnet;    private InputStream in;     // 输入流,接收返回信息    private PrintStream out;    // 向服务器写入 命令    /**     * @param termtype 协议类型：VT100、VT52、VT220、VTNT、ANSI     * @param prompt   结果结束标识     */    public TelnetTools(String termtype, String prompt) {        telnet = new TelnetClient(termtype);        setPrompt(prompt);    }    public TelnetTools(String termtype) {        telnet = new TelnetClient(termtype);    }    public TelnetTools() {        telnet = new TelnetClient();    }    /**     * 登录到目标主机     *     * @param ip     * @param port     */    public void login(String ip, int port) {        try {            telnet.connect(ip, port);            in = telnet.getInputStream();            out = new PrintStream(telnet.getOutputStream());        } catch (Exception e) {            throw new RuntimeException(e);        }    }    /**     * 读取分析结果     *     * @param pattern 匹配到该字符串时返回结果     * @return     */    public String readUntil(String pattern) {        StringBuffer sb = new StringBuffer();        try {            char lastChar = (char) -1;            boolean flag = pattern != null && pattern.length() > 0;            if (flag)                lastChar = pattern.charAt(pattern.length() - 1);            char ch;            int code = -1;            while ((code = in.read()) != -1) {                ch = (char) code;                sb.append(ch);                //匹配到结束标识时返回结果                if (flag) {                    if (ch == lastChar && sb.toString().endsWith(pattern)) {                        return sb.toString();                    }                } else {                    //如果没指定结束标识,匹配到默认结束标识字符时返回结果                    if (ch == promptChar)                        return sb.toString();                }                //登录失败时返回结果                if (sb.toString().contains("Login Failed")) {                    return sb.toString();                }            }        } catch (Exception e) {            e.printStackTrace();        }        return sb.toString();    }    /**     * 发送命令     *     * @param value     */    public void write(String value) {        try {            out.println(value);            out.flush();        } catch (Exception e) {            e.printStackTrace();        }    }    /**     * 发送命令,返回执行结果     *     * @param command     * @return     */    public String sendCommand(String command) {        try {            write(command);            return readUntil(prompt);        } catch (Exception e) {            e.printStackTrace();        }        return null;    }    /**     * 关闭连接     */    public void distinct() {        try {            if (telnet != null && !telnet.isConnected())                telnet.disconnect();        } catch (IOException e) {            e.printStackTrace();        }    }    public void setPrompt(String prompt) {        if (prompt != null) {            this.prompt = prompt;            this.promptChar = prompt.charAt(prompt.length() - 1);        }    }}

调用类

package com.tscloud.agent.flume.source.dataprovider;/** * 通过HTTP作为HDFS Master监控信息的source * 明细可参考http://zookeeper.apache.org/doc/r3.4.6/zookeeperAdmin.html#sc_zkCommands * @author aihua.sun * @date 2015/4/6 * @since V1.0 */import com.eric.agent.flume.model.ZookeeperRoleInfo;import com.eric.agent.flume.source.base.IClusterServiceRoleDataProvider;import com.eric.agent.utils.AgentConstants;import com.eric.agent.utils.TelnetTools;import com.eric.common.utils.StringUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import java.io.UnsupportedEncodingException;import java.util.*;public class ZookeeperDataProvider{    protected final Logger LOGGER = LoggerFactory.getLogger(getClass());    private static final String zk_avg_latency = "zk_avg_latency";    private static final String zk_max_latency = "zk_max_latency";    private static final String zk_min_latency = "zk_min_latency";    private static final String zk_packets_received = "zk_packets_received";    private static final String zk_packets_sent = "zk_packets_sent";    private static final String zk_server_state = "zk_server_state";    private static final String zk_znode_count = "zk_znode_count";    private static final String zk_followers = "zk_followers";    private static final String zk_open_file_descriptor_count = "zk_open_file_descriptor_count";    public String extractMonitorData() {        //TODO 通过调用API获得IP以及参数        ZookeeperRoleInfo monitorDataPoint = new ZookeeperRoleInfo();        String IP = "192.168.40.242";        int port = 2181;        TelnetTools telnet=null;        try {            telnet = new TelnetTools();            telnet.login(IP, port);            String rs = telnet.sendCommand("mntr");            Map<String, String> telnetResultMap = parseTelnetResult(rs);            monitorDataPoint.setZkAvgLatency(translateStrToLong(telnetResultMap.get(zk_avg_latency)));            monitorDataPoint.setZkMaxLatency(translateStrToLong(telnetResultMap.get(zk_max_latency)));            monitorDataPoint.setZkMinLatency(translateStrToLong(telnetResultMap.get(zk_min_latency)));            monitorDataPoint.setZkPacketsReceived(translateStrToLong(telnetResultMap.get(zk_packets_received)));            monitorDataPoint.setZkPacketsSent(translateStrToLong(telnetResultMap.get(zk_packets_sent)));            monitorDataPoint.setZkServerState(telnetResultMap.get(zk_server_state));            monitorDataPoint.setZkZnodeCount(translateStrToLong(telnetResultMap.get(zk_znode_count)));            monitorDataPoint.setZkFollowers(translateStrToLong(telnetResultMap.get(zk_followers)));            monitorDataPoint.setZkOpenFileDescriptorCount(translateStrToLong(telnetResultMap.get(zk_open_file_descriptor_count)));        } catch (Exception e) {            e.printStackTrace();        }finally{            telnet.distinct();        }        return monitorDataPoint.toString();    }    private Long translateStrToLong(String value) {        if (org.apache.commons.lang.StringUtils.isAlphanumeric(value)) {            return Long.valueOf(value);        }        return 0L;    }    private Map<String, String> parseTelnetResult(String rs) {        //The output contains multiple lines with the following format:        //key \t value        String[] resultArray = rs.split("\n");        Map<String, String> resultMap = new HashMap<String, String>();        for (String recordLine : resultArray) {            String[] recordKeyValue = recordLine.split("\t");            LOGGER.debug("############recordKeyValue.size:" + recordKeyValue.length + " recordKeyValue:" + Arrays.toString(recordKeyValue));            if (recordKeyValue != null && recordKeyValue.length == 2) {                resultMap.put(recordKeyValue[0], recordKeyValue[1]);            }        }        return resultMap;    }    public static void main(String[] args) {        System.out.println(new ZookeeperDataProvider().extractMonitorData());    }}