开发者手册

jmx-mbean

JMX

无法连接到指定应用程序

注意: 3867 是进程 ID

运行程序的时候使用如下命令:

1
2
3
-Dcom.sun.management.jmxremote.port=9005
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false

在调试 Tomcat 源码的时候就遇到了这个问题。

查看 MBeans 相关属性信息

jinfo

使用 root 权限运行就好了:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
zk@zk-pc:~/Documents$ jinfo 11279
Attaching to process ID 11279, please wait...
Error attaching to process: sun.jvm.hotspot.debugger.DebuggerException: Can't attach to the process: ptrace(PTRACE_ATTACH, ..) failed for 11279: Operation not permitted
sun.jvm.hotspot.debugger.DebuggerException: sun.jvm.hotspot.debugger.DebuggerException: Can't attach to the process: ptrace(PTRACE_ATTACH, ..) failed for 11279: 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 11279: 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)

CPU 占用率过高

1
2
3
4
5
6
7
8
9
10
11
12
$ top
 PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                        
12136 zk        20   0 4742404 100368  18432 S  99.7  1.7  20:43.61 java 

$ strace -t -p 46322
12:30:16 sched_yield()                  = 0
12:30:16 sched_yield()                  = 0
12:30:16 sched_yield()                  = 0
12:30:16 sched_yield()                  = 0
12:30:16 sched_yield()                  = 0
12:30:16 sched_yield()                  = 0
12:30:16 sched_yield()                  = 0

某种命令暂时无法运行/响应的

加上 -F 参数即可解决

1
2
3
4
5
$ jstack 12136
12136: Unable to open socket file: target process not responding or HotSpot VM not loaded
The -F option can be used when the target process is not responding
# /usr/lib/jvm/oracle_jdk8/jdk1.8.0_144/bin/jstack -F 12136
$ sudo -u root /usr/lib/jvm/oracle_jdk8/jdk1.8.0_144/bin/jstack -F 12136

推荐文章