Monitoring Hadoop

Collect and monitor general performance metrics for the JVM virtual machine in Hadoop.

Protocol used: JMX

Pre-monitoring steps

You need to enable JMX service in the Hadoop application before monitoring. HertzBeat uses the JMX protocol to collect performance metrics from Hadoop's JVM.

Steps to enable JMX protocol in the Hadoop application

Add JVM parameters when the application starts. ⚠️Note that you can customize the exposed port and external IP.

• 1.Enter the hadoop-env.sh configuration file and enter the following command in the terminal:

vi $HADOOP_HOME/etc/hadoop/hadoop-env.sh

• 2.Add the following parameters, where port is the number of the custom-exposed port

export HADOOP_OPTS= "$HADOOP_OPTS
-Djava.rmi.server.hostname=对外ip地址 
-Dcom.sun.management.jmxremote.port=9999
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.authenticate=false "

• 3.Save and exit, and then execute "start-all.sh" in the "$HADOOP_HOME/sbin" directory to restart the service.

Configuration parameter

Parameter name	Parameter help description
Monitoring Host	Monitored IPV4, IPV6 or domain name. Note⚠️Without protocol header (eg: https://, http://)
Monitoring name	Identify the name of this monitoring. The name needs to be unique
Port	Port provided by JMX
Username	JMX connection user name, optional
Password	JMX connection password, optional
Collection interval	Interval time of monitor periodic data collection, unit: second, and the minimum interval that can be set is 30 seconds
Whether to detect	Whether to detect and check the availability of monitoring before adding monitoring. Adding and modifying operations will continue only after the detection is successful
Description remarks	For more information about identifying and describing this monitoring, users can note information here

Collection Metrics

Metrics Set：memory_pool

Metric name	Metric unit	Metric help description
name		metrics name
committed	kb	total size
init	kb	init size
max	kb	max size
used	kb	used size

Metrics Set：code_cache (Only Support JDK8)

Metric name	Metric unit	Metric help description
committed	kb	total size
init	kb	init size
max	kb	max size
used	kb	used size

Metrics Set：class_loading

Metric name	Metric unit	Metric help description
LoadedClassCount		Loaded Class Count
TotalLoadedClassCount		Total Loaded Class Count
UnloadedClassCount		Unloaded Class Count

Metrics Set：thread

Metric name	Metric unit	Metric help description
TotalStartedThreadCount		Total Started Thread Count
ThreadCount		Thread Count
PeakThreadCount		Peak Thread Count
DaemonThreadCount		Daemon Thread Count
CurrentThreadUserTime	ms	Current Thread User Time
CurrentThreadCpuTime	ms	Current Thread Cpu Time