有没有办法用ibm-jdk for linux进行实时堆转储？

Question

我知道当在这个JVM上发生OutOfMemoryException时可以转储堆,但是可以用jmap或jconsole等工具询问实时转储吗？

Answer 1

您需要知道存在"系统"转储(基本上是OS核心文件)和"堆"又称可移动堆转储(PHD).后者不太有用,因为它们不包含实际数据.它们默认启用.

在AIX或Linux上通常,您将设置-Xdump:system(short for -Xdump:system:events=gpf+user)以允许kill -3 <pid>触发堆转储.

顺便说一下,你可以使用默认选项kill -ABRT <pid>.但是,这将终止您的JVM.

运行java -Xdump:what以查看默认值,例如:

> /usr/java6/bin/java -Xdump:what -version

Registered dump agents
----------------------
-Xdump:system:
    events=gpf+abort+traceassert,
    label=/home/u0002824/core.%Y%m%d.%H%M%S.%pid.%seq.dmp,
    range=1..0,
    priority=999,
    request=serial
----------------------
...
java version "1.6.0"
Java(TM) SE Runtime Environment (build pap3260sr9fp2-20110627_03(SR9 FP2))

打开系统转储:

> /usr/java6/bin/java -Xdump:system -Xdump:what -version

Registered dump agents
----------------------
-Xdump:system:
    events=gpf+user+abort+traceassert,
    label=/home/u0002824/core.%Y%m%d.%H%M%S.%pid.%seq.dmp,
    range=1..0,
    priority=999,
    request=serial
----------------------
-Xdump:heap:
    events=systhrow,
    filter=java/lang/OutOfMemoryError,
    label=/home/u0002824/heapdump.%Y%m%d.%H%M%S.%pid.%seq.phd,
    range=1..4,
    priority=500,
    request=exclusive+compact+prepwalk,
    opts=PHD
----------------------
-Xdump:java:
    events=gpf+user+abort+traceassert,
    label=/home/u0002824/javacore.%Y%m%d.%H%M%S.%pid.%seq.txt,
    range=1..0,
    priority=400,
    request=exclusive+preempt
----------------------
-Xdump:java:
    events=systhrow,
    filter=java/lang/OutOfMemoryError,
    label=/home/u0002824/javacore.%Y%m%d.%H%M%S.%pid.%seq.txt,
    range=1..4,
    priority=400,
    request=exclusive+preempt
----------------------
-Xdump:snap:
    events=gpf+abort+traceassert,
    label=/home/u0002824/Snap.%Y%m%d.%H%M%S.%pid.%seq.trc,
    range=1..0,
    priority=300,
    request=serial
----------------------
-Xdump:snap:
    events=systhrow,
    filter=java/lang/OutOfMemoryError,
    label=/home/u0002824/Snap.%Y%m%d.%H%M%S.%pid.%seq.trc,
    range=1..4,
    priority=300,
    request=serial
----------------------
...

不要忘记jre/bin/jextract在核心上运行.*.dmp文件.

Answer 2

好吧，我最终会回答自己：应用程序有一个远程管理界面，所以我将实现一个调用该方法的新命令com.ibm.jvm.Dump.HeapDump()。