JAVA 메모리 테스트를 위한 jmap 사용하기

jmap은 JVM을 모니터링할 수 있는 도구이며, cmd에서 명령어로 사용한다.

힙덤프 뜨라고 하면 jmap으로 하면 된다.

 

2. 주요 명령어

1) heap 요약 보기

# jmap -heap [pid]

2) heap dump 뜨기

- heap dump 파일 생성: jmap -dump:format=b,file=[파일명] [PID]

  ex) # jmap -dump:format=b,file=heapdump20210224.hprof 2626

 

1. jmap 사용법

jmap의 사용법은 다음과 같다.

# jmap
Usage:
    jmap [option] <pid>
        (to connect to running process)
    jmap [option] <executable <core>
        (to connect to a core file)
    jmap [option] [server_id@]<remote server IP or hostname>
        (to connect to remote debug server)

where <option> is one of:
    <none>               to print same info as Solaris pmap
    -heap                to print java heap summary
    -histo[:live]        to print histogram of java object heap; if the "live"
                         suboption is specified, only count live objects
    -clstats             to print class loader statistics
    -finalizerinfo       to print information on objects awaiting finalization
    -dump:<dump-options> to dump java heap in hprof binary format
                         dump-options:
                           live         dump only live objects; if not specified,
                                        all objects in the heap are dumped.
                           format=b     binary format
                           file=<file>  dump heap to <file>
                         Example: jmap -dump:live,format=b,file=heap.bin <pid>
    -F                   force. Use with -dump:<dump-options> <pid> or -histo
                         to force a heap dump or histogram when <pid> does not
                         respond. The "live" suboption is not supported
                         in this mode.
    -h | -help           to print this help message
    -J<flag>             to pass <flag> directly to the runtime system