jvm performance analysis tools

jvm performance analysis

pid lists all the native java process: First, JPS

　　Command Options

• -q output VM identifier only, not including the class name, jar name, arguments in main method
• -m output main method parameters
• -l output of the full package name, application name of the main class, jar full pathname
• -v output parameters jvm
• -V output to a JVM parameters (.hotspotrc document or file by the flag of -XX: Flags = the specified file
• -Joption pass parameters to vm, for example: -J-Xms48m

Two, jmap: Performance Tuning Tools

　　jmap -help to view command instructions

　　As shown, the command format: jmap [option] <pid>

　　parameter:

• option:  Option parameter.
• pid:  the need to print a configuration process ID information.
• executable:  generating a core dump of the Java executable.
• core:  the need to print the core configuration file information.
• server-id  optional unique id, if multiple debug servers running on the same remote host, this option parameter identifies the server.
• Server hostname or IP Remote  IP address or host name of the remote debugging server.

　　option parameters:

• no option:  the memory image to view process information, similar to the Solaris pmap command.
• heap:  show Java heap Details
• histo [: live]:  Displays statistics object on the heap
• clstats: print class loader information
• finalizerinfo:  displaying an object queue for execution of the method finalizer thread F-Queue Finalizer
• dump: <dump-options>: green heap dump snapshots
• F:  When -dump no response, or the -dump parameters -histo In this mode, the sub-Live parameter is invalid.
• help: print help
• J <flag>: Specifies the JVM to the runtime parameters jmap

 

 

 

 

 

 

 

 

 

 

 

Three, jstack: viewing thread stacks within a Java process information

jstack main thread stack used to view information in a Java process. Syntax is as follows:

jstack [option] pid

Parameters are as follows:

1. -l long listings, will print out additional lock information, you can use jstack -l pid locks held to observe the situation when a deadlock occurs
2. -m mixed mode, not only will output Java stack information will be printed in C / C ++ stack information (such as Native Method)

 

 

 

Four, jstat: JVM statistics monitoring tool

1000ms recorded every time printing, the print 10 is stopped, the print head after each 3 row index

 jstat -gc -h3 10 1000 10

 

 

Five, hprof: show CPU usage, memory usage statistics heap

 

Six, Top: printing process uses resources