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I have a running JVM with two threads. Is it possible to see these running threads on my Linux OS with ps -axl ? I am trying to find out what priority the OS is giving to my threads. More info about this other issue here.
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Using the top command The top command can show a real-time view of individual threads. To enable thread views in the top output, invoke top with "-H" option. This will list all Linux threads. You can also toggle on or off thread view mode while top is running, by pressing 'H' key.
Identifying the thread On Unix® and Linux® systems, you can use the top command: $ top -n 1 -H -p [pid]replacing [pid] with the process ID of the affected process. On Solaris®, you can use the prstat command: $ prstat -L -p [pid]replacing [pid] with the process ID of the affected process.
In ps command, "-T" option enables thread views. The following command list all threads created by a process with <pid>. The "SID" column represents thread IDs, and "CMD" column shows thread names.
In the GNU C Library implementation running on Linux, the process ID is the thread group ID of all threads in the process. You can get the process ID of a process by calling getpid . The function getppid returns the process ID of the parent of the current process (this is also known as the parent process ID).
Use
jps -v for finding your java process. Sample Output:
3825 RemoteMavenServer -Djava.awt.headless=true -Xmx512m -Dfile.encoding=MacRoman 6172 AppMain -Didea.launcher.port=7533 -Didea.launcher.bin.path=/Applications/IntelliJ IDEA 10.app/bin -Dfile.encoding=UTF-8 6175 Jps -Dapplication.home=/Library/Java/JavaVirtualMachines/1.6.0_31-b04-411.jdk/Contents/Home -Xms8m Then use
jstack 6172 (6172 is id of your process) to get stack of threads inside jvm. Thread priority could be found from it. Sample output:
..... "main" **prio=5** tid=7ff255800800 nid=0x104bec000 waiting on condition [104beb000] java.lang.Thread.State: TIMED_WAITING (sleeping) at java.lang.Thread.sleep(Native Method) at au.com.byr.Sample.main(Sample.java:11) 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 com.intellij.rt.execution.application.AppMain.main(AppMain.java:120) ..... Enjoy!
EDIT: If application running under different user than yourself (typical case on production and other non-local environments) then jps/jstack should be run via sudo. Examples:
sudo jps -v sudo jstack 6172 If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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