Use TelnetClient to obtain Zookeeper Monitoring Data

Use TelnetClient to obtain Zookeeper Monitoring Data

To write a Java program that monitors Zookeeper, you can use either of the following methods:

(1) send commands through TelnetClient, detailed command reference: http://zookeeper.apache.org/doc/trunk/zookeeperAdmin.html# SC _zkCommands

(2) Through JMX, instructions please refer to: http://zookeeper.apache.org/doc/trunk/zookeeperJMX.html

This article uses a simple example to demonstrate how to use TelnetClient to send mntr commands to obtain the monitoring data of Zookeeper.

Write a Telnet tool class

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 operator, based on commons-net-2.2.jar
*
* @ Author aihua. sun
* @ Date 2015/4/9
* @ Since V1.0
*/
Public class TelnetTools {
Private String prompt = ">"; // end ID String. For Windows, yes>, for Linux #
Private char promptChar = '>'; // end identifier
Private TelnetClient telnet;
Private InputStream in; // input stream, receiving returned information
Private PrintStream out; // write commands to the server
/**
* @ Param termtype: VT100, VT52, VT220, VTNT, and ANSI
* @ Param prompt indicates the end of the result.
*/
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 ();
}
/**
* Log on to the target host
*
* @ 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 );
}
}
/**
* Read the analysis results
*
* @ Param pattern returns the result when the string is matched.
* @ 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 );
// Return results when the end ID is matched
If (flag ){
If (ch = lastChar & sb. toString (). endsWith (pattern )){
Return sb. toString ();
}
} Else {
// If no end identifier is specified, the result is returned when the default end identifier is matched.
If (ch = promptChar)
Return sb. toString ();
}
// Return results when logon fails
If (sb. toString (). contains ("Login Failed ")){
Return sb. toString ();
}
}
} Catch (Exception e ){
E. printStackTrace ();
}
Return sb. toString ();
}
/**
* Send command
*
* @ Param value
*/
Public void write (String value ){
Try {
Out. println (value );
Out. flush ();
} Catch (Exception e ){
E. printStackTrace ();
}
}
/**
* Send the command and return the execution result.
*
* @ Param command
* @ Return
*/
Public String sendCommand (String command ){
Try {
Write (command );
Return readUntil (prompt );
} Catch (Exception e ){
E. printStackTrace ();
}
Return null;
}
/**
* Close the connection.
*/
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 );
}
}
}

Call class

Package com. tscloud. agent. flume. source. dataprovider;

/**
* Use HTTP as the source of HDFS Master monitoring information
* Details can refer to the 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 obtains the IP address and parameters by calling the API.
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 ());
}

}

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