jmap錯誤：unknown CollectedHeap type : class sun.jvm.hotspot.gc_interface.CollectedHeap

使用jmap -heap命令查看堆的詳細信息報錯

Caused by: java.lang.RuntimeException: unknown CollectedHeap type : class sun.jvm.hotspot.gc_interface.CollectedHeap

[root@bangbet-java ~]# jmap -heap 27822
Attaching to process ID 27822, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.222-b10

using thread-local object allocation.
Parallel GC with 4 thread(s)

Heap Configuration:
   MinHeapFreeRatio         = 0
   MaxHeapFreeRatio         = 100
   MaxHeapSize              = 1073741824 (1024.0MB)
   NewSize                  = 536870912 (512.0MB)
   MaxNewSize               = 536870912 (512.0MB)
   OldSize                  = 536870912 (512.0MB)
   NewRatio                 = 2
   SurvivorRatio            = 8
   MetaspaceSize            = 21807104 (20.796875MB)
   CompressedClassSpaceSize = 1073741824 (1024.0MB)
   MaxMetaspaceSize         = 17592186044415 MB
   G1HeapRegionSize         = 0 (0.0MB)

Heap Usage:
Exception in thread "main" java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at sun.tools.jmap.JMap.runTool(JMap.java:201)
        at sun.tools.jmap.JMap.main(JMap.java:130)
Caused by: java.lang.RuntimeException: unknown CollectedHeap type : class sun.jvm.hotspot.gc_interface.CollectedHeap
        at sun.jvm.hotspot.tools.HeapSummary.run(HeapSummary.java:157)
        at sun.jvm.hotspot.tools.Tool.startInternal(Tool.java:260)
        at sun.jvm.hotspot.tools.Tool.start(Tool.java:223)
        at sun.jvm.hotspot.tools.Tool.execute(Tool.java:118)
        at sun.jvm.hotspot.tools.HeapSummary.main(HeapSummary.java:50)
        ... 6 more

奇怪，在本地是沒問題的，在linux上卻出現這種情況

查看了下jdk版本，都是1.8，沒啥問題呀

本地是HotSpot

線上是OpenJDK

最終原因

這里-heap參數會調用用到了sun.jvm下的debug包，而默認openJDK的安裝中不包含！

解決方式

下載並安裝一個java-openjdk-debug插件！而且需要和openjdk小版本也一致！！！

安裝debuginfo

去網站http://debuginfo.centos.org/7/x86_64里面找匹配當前的openjdk的版本，小版本號也要匹配上。

然后使用wget命令下載

wget http://debuginfo.centos.org/7/x86_64/java-1.8.0-openjdk-debuginfo-1.8.0.222.b10-0.el7_6.x86_64.rpm

使用rpm命令安裝

rpm -ivh java-1.8.0-openjdk-debuginfo-1.8.0.222.b10-0.el7_6.x86_64.rpm

查看是否安裝了debuginfo

[root@bangbet-java ~]# rpm -qa|grep debuginfo
java-1.8.0-openjdk-debuginfo-1.8.0.222.b10-0.el7_6.x86_64

再次查詢

[root@bangbet-java ~]# jmap -heap 27968
Attaching to process ID 27968, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.222-b10

using thread-local object allocation.
Parallel GC with 4 thread(s)

Heap Configuration:
   MinHeapFreeRatio         = 0
   MaxHeapFreeRatio         = 100
   MaxHeapSize              = 2147483648 (2048.0MB)
   NewSize                  = 1073741824 (1024.0MB)
   MaxNewSize               = 1073741824 (1024.0MB)
   OldSize                  = 1073741824 (1024.0MB)
   NewRatio                 = 2
   SurvivorRatio            = 8
   MetaspaceSize            = 21807104 (20.796875MB)
   CompressedClassSpaceSize = 1073741824 (1024.0MB)
   MaxMetaspaceSize         = 17592186044415 MB
   G1HeapRegionSize         = 0 (0.0MB)

Heap Usage:
PS Young Generation
Eden Space:
   capacity = 1054867456 (1006.0MB)
   used     = 521443544 (497.28731536865234MB)
   free     = 533423912 (508.71268463134766MB)
   49.43213870463741% used
From Space:
   capacity = 8388608 (8.0MB)
   used     = 8377312 (7.989227294921875MB)
   free     = 11296 (0.010772705078125MB)
   99.86534118652344% used
To Space:
   capacity = 9437184 (9.0MB)
   used     = 0 (0.0MB)
   free     = 9437184 (9.0MB)
   0.0% used
PS Old Generation
   capacity = 1073741824 (1024.0MB)
   used     = 334280072 (318.79431915283203MB)
   free     = 739461752 (705.205680847168MB)
   31.132257729768753% used

35880 interned Strings occupying 4018400 bytes.

ok，解決完畢！

遇到的版本問題

我的jdk版本是1.8.0_222-b10，在http://debuginfo.centos.org/7/x86_64找到兩個

先下載了個最新的發現並不好使，之后卸載重新下載另一個

rpm卸載

rpm -e --nodeps java-1.8.0-openjdk-debuginfo-1:1.8.0.222.b10-1.el7_7.x86_64

之后重新安裝即可