jmap

Java Memory Map Tool.

• Print shared object mappings for a java process (output like pmap):

jmap {{java_pid}}

• Print heap summary information:

jmap -heap {{filename.jar}} {{java_pid}}

• Print histogram of heap usage by type:

jmap -histo {{java_pid}}

• Dump contents of the heap into a binary file for analysis with jhat:

jmap -dump:format=b,file={{filename}} {{java_pid}}