jinfo 示例

• jinfo -flags 108
• 打印tomcat进程已经被手动赋过值的参数，然而报错了，这好像是jdk的一个bug，先不管；
• 应该是和Docker的CentOS6.8镜像有关，或者是和CentOS6.8这个版本有关；

[root@jvm001 ~]# jps -l
182 sun.tools.jps.Jps
108 org.apache.catalina.startup.Bootstrap
[root@jvm001 ~]# jinfo -flags 108
Attaching to process ID 108, please wait...
Error attaching to process: sun.jvm.hotspot.debugger.DebuggerException: Can't attach to the process: ptrace(PTRACE_ATTACH, ..) failed for 108: Operation not permitted
sun.jvm.hotspot.debugger.DebuggerException: sun.jvm.hotspot.debugger.DebuggerException: Can't attach to the process: ptrace(PTRACE_ATTACH, ..) failed for 108: Operation not permitted
    at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal$LinuxDebuggerLocalWorkerThread.execute(LinuxDebuggerLocal.java:163)
    at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal.attach(LinuxDebuggerLocal.java:278)
    at sun.jvm.hotspot.HotSpotAgent.attachDebugger(HotSpotAgent.java:671)
    at sun.jvm.hotspot.HotSpotAgent.setupDebuggerLinux(HotSpotAgent.java:611)
    at sun.jvm.hotspot.HotSpotAgent.setupDebugger(HotSpotAgent.java:337)
    at sun.jvm.hotspot.HotSpotAgent.go(HotSpotAgent.java:304)
    at sun.jvm.hotspot.HotSpotAgent.attach(HotSpotAgent.java:140)
    at sun.jvm.hotspot.tools.Tool.start(Tool.java:185)
    at sun.jvm.hotspot.tools.Tool.execute(Tool.java:118)
    at sun.jvm.hotspot.tools.JInfo.main(JInfo.java:138)
    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.jinfo.JInfo.runTool(JInfo.java:108)
    at sun.tools.jinfo.JInfo.main(JInfo.java:76)
Caused by: sun.jvm.hotspot.debugger.DebuggerException: Can't attach to the process: ptrace(PTRACE_ATTACH, ..) failed for 108: Operation not permitted
    at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal.attach0(Native Method)
    at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal.access$100(LinuxDebuggerLocal.java:62)
    at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal$1AttachTask.doit(LinuxDebuggerLocal.java:269)
    at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal$LinuxDebuggerLocalWorkerThread.run(LinuxDebuggerLocal.java:138)

• 在本机Windows10上倒是可以，jdk版本是1.8.0_91；
• 这是个在IDEA里启动的SpringBoot程序；

PS C:\Users\LiXinlei> jps -l
10500 org.jetbrains.idea.maven.server.RemoteMavenServer
17780 com.example.demo.DemoApplication
18088 sun.tools.jps.Jps
11516
PS C:\Users\LiXinlei> jinfo -flags 17780
Attaching to process ID 17780, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.111-b14
Non-default VM flags: -XX:CICompilerCount=4 -XX:InitialHeapSize=268435456 -XX:MaxHeapSize=4273995776 -XX:MaxNewSize=1424490496 -XX:MinHeapDeltaBytes=524288 -XX:NewSize=89128960 -XX:OldSize=179306496 -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseFastUnorderedTimeStamps -XX:-UseLargePagesIndividualAllocation -XX:+UseParallelGC
Command line:  -javaagent:D:\Program Files\JetBrains\IntelliJ IDEA 2017.3\lib\idea_rt.jar=55114:D:\Program Files\JetBrains\IntelliJ IDEA 2017.3\bin -Dfile.encoding=UTF-8