JVM (III) Virtual machine performance monitoring & fault handling tool

JVM ( 3、 ... and ). Virtual machine performance monitoring & Troubleshooting tools

1. summary

System positioning problem , Tools are needed to export the data in question ; The data here has an exception stack , Virtual machine log , Garbage collection log , Thread snapshot , Heap snapshot file ; There are many tools, such as the tools provided by the virtual machine or the third-party parsing tools ;

2. Basic tools

In the catalog JAVA_HOME/bin/ Inside

2.1 jps

jps: （JVM Precess Status） Virtual machine process health tool ： List the running virtual machine processes , And display the main class ;

jps Command format ：

jps  [options] [hostid]

Options	effect
-q	Only the output LVMID Omit the name of the main class
-m	To main class mian() Method parameters
-l	Full name of main class , If it is jar package It is jar Package address
-v	Startup time JVM Parameters

[[email protected] ~]# jps -q
1424
129685
77724
1742
[[email protected] ~]# jps -m
1424 QuorumPeerMain /package/zookeeper/bin/../conf/zoo.cfg
129700 Jps -m
77724 KafkaEagle start
1742 Kafka config/server.properties
[[email protected] ~]# jps -l
1424 org.apache.zookeeper.server.quorum.QuorumPeerMain
129712 sun.tools.jps.Jps
77724 org.apache.catalina.startup.KafkaEagle
1742 kafka.Kafka
[[email protected] ~]# jps -v
1424 QuorumPeerMain -Dzookeeper.log.dir=. -Dzookeeper.root.logger=INFO,CONSOLE -Dcom.sun.management.jmxremote -Dcom.sun.management.j
mxremote.local.only=false129725 Jps -Denv.class.path=.:/usr/local/jdk/jdk1.8.0_51//lib/tools.jar:/usr/local/jdk/jdk1.8.0_51//lib/dt.jar: -Dapplication.home=/
usr/local/jdk/jdk1.8.0_51 -Xms8m77724 KafkaEagle -Djava.util.logging.config.file=/package/kafka-eagle/kms/conf/logging.properties -Djava.util.logging.manager=org.ap
ache.juli.ClassLoaderLogManager -Xmx1g -Xms1g -XX:MaxGCPauseMillis=20 -XX:+UseG1GC -XX:MetaspaceSize=128m -XX:InitiatingHeapOccupancyPercent=35 -XX:G1HeapRegionSize=16M -XX:MinMetaspaceFreeRatio=50 -XX:MaxMetaspaceFreeRatio=80 -Djdk.tls.ephemeralDHKeySize=2048 -Djava.protocol.handler.pkgs=org.apache.catalina.webresources -Dorg.apache.catalina.security.SecurityListener.UMASK=0027 -Dignore.endorsed.dirs= -Dcatalina.base=/package/kafka-eagle/kms -Dcatalina.home=/package/kafka-eagle/kms -Djava.io.tmpdir=/package/kafka-eagle/kms/temp1742 Kafka -Xmx1G -Xms1G -XX:+UseG1GC -XX:MaxGCPauseMillis=20 -XX:InitiatingHeapOccupancyPercent=35 -XX:+ExplicitGCInvokesConcurrent
 -Djava.awt.headless=true -Xloggc:/package/kafka/bin/../logs/kafkaServer-gc.log -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.port=7788 -Dkafka.logs.dir=/package/kafka/bin/../logs -Dlog4j.configuration=file:./bin/../config/log4j.properties

2.2 jstat

jstat: JVM Statistics Monitoring Tool ： Command line tool for monitoring virtual machine running status information

jstat Command format ：

jstat [option vmid [interval[s|ms] [count]]

Options	effect
-class	Class information loaded by virtual machine
-gc	Heap information detection Garbage collection information
-gcutil	-gc The information is about the same Percentage form
-gccause	The last time gc reason
...	....

[[email protected] ~]# jps -l
1424 org.apache.zookeeper.server.quorum.QuorumPeerMain
3512 sun.tools.jps.Jps
77724 org.apache.catalina.startup.KafkaEagle
1742 kafka.Kafka
[[email protected] ~]# jstat -gc 1424 100 10 // 1424 pid 100ms  once   in total 10 Time 
 S0C    S1C    S0U    S1U      EC       EU        OC         OU       MC     MU    CCSC   CCSU   YGC     YGCT    FGC    FGCT     GCT   
512.0  512.0  512.0   0.0   15360.0   6986.6   20480.0     5191.8   11008.0 10679.9 1280.0 1198.4     58    2.944   0      0.000    2.944
512.0  512.0  512.0   0.0   15360.0   6986.6   20480.0     5191.8   11008.0 10679.9 1280.0 1198.4     58    2.944   0      0.000    2.944
512.0  512.0  512.0   0.0   15360.0   6986.6   20480.0     5191.8   11008.0 10679.9 1280.0 1198.4     58    2.944   0      0.000    2.944
512.0  512.0  512.0   0.0   15360.0   6986.6   20480.0     5191.8   11008.0 10679.9 1280.0 1198.4     58    2.944   0      0.000    2.944
512.0  512.0  512.0   0.0   15360.0   6986.6   20480.0     5191.8   11008.0 10679.9 1280.0 1198.4     58    2.944   0      0.000    2.944
512.0  512.0  512.0   0.0   15360.0   6986.6   20480.0     5191.8   11008.0 10679.9 1280.0 1198.4     58    2.944   0      0.000    2.944
512.0  512.0  512.0   0.0   15360.0   7055.9   20480.0     5191.8   11008.0 10679.9 1280.0 1198.4     58    2.944   0      0.000    2.944
512.0  512.0  512.0   0.0   15360.0   7055.9   20480.0     5191.8   11008.0 10679.9 1280.0 1198.4     58    2.944   0      0.000    2.944
512.0  512.0  512.0   0.0   15360.0   7055.9   20480.0     5191.8   11008.0 10679.9 1280.0 1198.4     58    2.944   0      0.000    2.944
512.0  512.0  512.0   0.0   15360.0   7074.3   20480.0     5191.8   11008.0 10679.9 1280.0 1198.4     58    2.944   0      0.000    2.944
[[email protected] ~]# jstat -gcutil 1424 100 10
  S0     S1     E      O      M     CCS    YGC     YGCT    FGC    FGCT     GCT   
100.00   0.00  47.29  25.35  97.02  93.63     58    2.944     0    0.000    2.944
100.00   0.00  47.29  25.35  97.02  93.63     58    2.944     0    0.000    2.944
100.00   0.00  47.29  25.35  97.02  93.63     58    2.944     0    0.000    2.944
100.00   0.00  47.29  25.35  97.02  93.63     58    2.944     0    0.000    2.944
100.00   0.00  47.29  25.35  97.02  93.63     58    2.944     0    0.000    2.944
100.00   0.00  47.29  25.35  97.02  93.63     58    2.944     0    0.000    2.944
100.00   0.00  47.29  25.35  97.02  93.63     58    2.944     0    0.000    2.944
100.00   0.00  47.29  25.35  97.02  93.63     58    2.944     0    0.000    2.944
100.00   0.00  47.29  25.35  97.02  93.63     58    2.944     0    0.000    2.944
100.00   0.00  47.29  25.35  97.02  93.63     58    2.944     0    0.000    2.944

2.3 jinfo

jinfo: Configuration Info for Java ： View and adjust various parameters of virtual machine in real time

jinfo Command format ：

jinfo [option ] pid

[[email protected] ~]# jinfo 1424
Attaching to process ID 1424, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.51-b03
Java System Properties:

java.runtime.name = Java(TM) SE Runtime Environment
java.vm.version = 25.51-b03
..........
VM Flags:
........

2.4 jmap

jmap:Memery Map for Java ： Heap memory snapshot heapdump /dump

jmap Command format ：

Options	effect
-dump	Generate a heap snapshot
-finallizerinfo	F-Queue Information
-heap	Linux It works Java Heap information
-histo	Statistics of objects in the heap Number of class instances , Aggregate capacity
-F	-dump When there is no response Force generation

C:\Users\sff>jmap -dump:format=b,file=test.bin 19140
Dumping heap to C:\Users\sff\test.bin ...
Heap dump file created

2.5 jhat

jhat: JVM Heap Analysis Tool ： Resolve heap memory snapshot dump file

jhat Command format ：

jhat [ file ]

C:\Users\sff>jhat test.bin
Reading from test.bin...
Dump file created Sun Jan 23 22:32:09 CST 2022
Snapshot read, resolving...
Resolving 118891 objects...
Chasing references, expect 23 dots.......................
Eliminating duplicate references.......................
Snapshot resolved.
Started HTTP server on port 7000
Server is ready.
 Access address ： http://localhost:7000/

2.6jstack

jstack: Stack Trace for Java ： Generate a snapshot of the current virtual machine thread

jstack Command format ：

jsatck [option] pid

Options	effect
-F	Output does not respond Forced response
-l	Except for the stack And lock information
-m	When it comes to local methods You can also show C/C++

2.7 Other commands

command	effect
java	Run the command function Class Documents or jar package
javac	Compiler tools
javap	Bytecode analysis tool Decompile

3. Visual fault handling tool

3.1 JConsole

Java Monitoring and Management ConsoleJava Monitoring and management console ; be based on JMX Visual tools , adopt JMX management MBean;

adopt pid Or the class name is connected to the service you want to see running JVM situation

Mainly ： Memory monitoring Memory usage of each area of the virtual machine GC situation ; Thread monitoring is a bit like jstack, There is also deadlock detection below

3.2 VisualVM

All-in-One Java Troubleshooting Tool It is one of the most powerful operation monitoring and fault handling programs , For a long time Oracle Official failure handling tools for virtual machines

If the computer is configured with environment variables ; Direct input jvisualvm You can open it directly , Connect your own application , View the application running JVM The state of ; There are also many plug-ins with rich functions ;

3.3 MAT

Eclipse Of Memory Analyzer Tool （MAT）; Personal use is still more , General users view the problem of memory leakage ; Load memory snapshot directly , Click the object that occupies more memory ;