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 -heap27822Attaching to process ID 27822, pleasewait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.222-b10
using thread-localobject 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 inthread"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)
? ? ? ? ... 6more
奇怪，在本地是沒問題的，在linux上卻出現(xiàn)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(shù)會調(diào)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
下載并安裝一個java-openjdk-debug插件！而且需要和openjdk小版本也一致?。?！
安裝debuginfo
去網(wǎng)站http://debuginfo.centos.org/7/x86_64里面找匹配當(dāng)前的openjdk的版本，小版本號也要匹配上。
然后使用wget命令下載
wgethttp://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 -heap27968Attaching to process ID 27968, pleasewait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.222-b10
using thread-localobject 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% used35880interned Strings occupying4018400bytes.
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(fā)現(xiàn)并不好使，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
