问题：使用jmap命令查看某个进程的堆情况时(jmap -heap 198376)，抛异常如下：
Attaching to process ID 198376, please wait...
Exception in thread "main" java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at sun.tools.jmap.JMap.runTool(JMap.java:179)
at sun.tools.jmap.JMap.main(JMap.java:110)
Caused by: java.lang.RuntimeException: Type "nmethodBucket*", referenced in VMStructs::localHotSpotVMStructs in the remote VM, was not present in the remote VMStructs::localHotSpotVMTypes table (should have been caught in the debug build of that VM). Can not continue.
at sun.jvm.hotspot.HotSpotTypeDataBase.lookupOrFail(HotSpotTypeDataBase.java:362)
at sun.jvm.hotspot.HotSpotTypeDataBase.readVMStructs(HotSpotTypeDataBase.java:253)
at sun.jvm.hotspot.HotSpotTypeDataBase.<init>(HotSpotTypeDataBase.java:87)
at sun.jvm.hotspot.bugspot.BugSpotAgent.setupVM(BugSpotAgent.java:568)
at sun.jvm.hotspot.bugspot.BugSpotAgent.go(BugSpotAgent.java:494)
at sun.jvm.hotspot.bugspot.BugSpotAgent.attach(BugSpotAgent.java:332)
at sun.jvm.hotspot.tools.Tool.start(Tool.java:163)
at sun.jvm.hotspot.tools.HeapSummary.main(HeapSummary.java:39)
... 6 more
解决方法：
抛异常原因是该进程运行所用的java和使用jmap时的java不是同一个版本，使用和所运行程序相同的java版本即可。很可能是因为机器上装有多个jdk，默认路径下的jmap和所运行进程使用的不是同一个jdk，所以抛异常了。解决办法是使用全路径，如/usr/local/jdk1.7.0_80/bin/jmap -heap 198376
http://blog.csdn.net/prstaxy/article/details/51097605