How can I monitor the thread count of a process on linux

Question

I would like to monitor the number of threads used by a specific process on Linux  Is there an easy way to get this information without impacting the performance of the process

User · Answer

try  ps huH p  lt PID OF U PROCESS gt    wc -l   or htop

User · Answer

Each thread in a process creates a directory under  proc  lt pid gt  task  Count the number of directories  and you have the number of threads

User · Answer

VisualVM can show clear states of threads of a given JVM process

User · Answer

ps H p pid-id  H - Lists all the individual threads in a process  or   cat  proc pid-id status  pid-id is the Process ID  eg    Truncated the below output   root abc    cat  proc 8443 status Name    abcdd State   S  sleeping  Tgid    8443 VmSwap         0 kB Threads     4 SigQ    0 256556 SigPnd  0000000000000000

User · Answer

jvmtop can show the current jvm thread count beside other metrics

User · Answer

Newer JDK distributions ship with JConsole and VisualVM  Both are fantastic tools for getting the dirty details from a running Java process  If you have to do this programmatically  investigate JMX

User · Answer

If you use   ps uH p  lt PID OF U PROCESS gt    wc -l   You have to subtract 1 to the result  as one of the lines  wc  is counting is the headers of the  ps  command

User · Answer

cat  proc  lt PROCESS PID gt  status   grep Threads

User · Answer

If you re interested in those threads which are really active -- as in doing something  not blocked  not timed waiting  not reporting  thread running  but really waiting for a stream to give data  as opposed to sitting around idle but live -- then you might be interested in jstack-active   This simple bash script runs jstack then filters out all the threads which by heuristics seem to be idling  showing you stack traces for those threads which are actually consuming CPU cycles

User · Answer

JStack is quite inexpensive - one option would be to pipe the output through grep to find active threads and then pipe through wc -l   More graphically is JConsole  which displays the thread count for a given process

User · Answer

Each thread in a process creates a directory under  proc  lt pid gt  task  Count the number of directories  and you have the number of threads

User · Answer

If you re looking for thread count for multiple processes  the other answers won t work well for you  since you won t see the process names or PIDs  which makes them rather useless  Use this instead  ps -o pid nlwp args -p  lt pid 1 gt   lt pid 2 gt       lt pid N gt   In order to watch the changes live  just add watch  watch ps -o pid nlwp args -p  lt pid 1 gt   lt pid 2 gt       lt pid N gt

User · Answer

If you want the number of threads per user in a linux system then you should use  ps -eLf   grep  lt USER gt    awk    num     6   END   print num     where as  lt USER gt  use the desired user name

User · Answer

Here is one command that displays the number of threads of a given process    ps -L -o pid  -p  lt pid gt    wc -l   Unlike the other ps based answers  there is here no need to substract 1 from its output as there is no ps header line thanks to the -o pid option

User · Answer

To get the number of threads for a given pid     ps -o nlwp  lt pid gt    Where nlwp stands for Number of Light Weight Processes  threads   Thus ps aliases nlwp to thcount  which means that    ps -o thcount  lt pid gt    does also work   If you want to monitor the thread count  simply use watch     watch ps -o thcount  lt pid gt    To get the sum of all threads running in the system     ps -eo nlwp   tail -n  2   awk    num threads     1   END   print num threads

User · Answer

The easiest way is using  htop   You can install  htop   a fancier version of top  which will show you all your cores  process and memory usage   Press  Shift H  to show all process or press again to hide it  Press  F4  key to search your process name   Installing on Ubuntu or Debian   sudo apt-get install htop   Installing on Redhat or CentOS   yum install htop dnf install htop       On Fedora 22  releases    If you want to compile  htop  from source code  you will find it here

User · Answer

cat  proc  lt PROCESS PID gt  status   grep Threads

User · Answer

ps -eLf on the shell shall give you a list of all the threads and processes currently running on the system  Or  you can run top command then hit  H  to toggle thread listings

User · Answer

JStack is quite inexpensive - one option would be to pipe the output through grep to find active threads and then pipe through wc -l   More graphically is JConsole  which displays the thread count for a given process

User · Answer

Newer JDK distributions ship with JConsole and VisualVM  Both are fantastic tools for getting the dirty details from a running Java process  If you have to do this programmatically  investigate JMX

User · Answer

VisualVM can show clear states of threads of a given JVM process

User · Answer

JStack is quite inexpensive - one option would be to pipe the output through grep to find active threads and then pipe through wc -l   More graphically is JConsole  which displays the thread count for a given process

User · Answer

If you re interested in those threads which are really active -- as in doing something  not blocked  not timed waiting  not reporting  thread running  but really waiting for a stream to give data  as opposed to sitting around idle but live -- then you might be interested in jstack-active   This simple bash script runs jstack then filters out all the threads which by heuristics seem to be idling  showing you stack traces for those threads which are actually consuming CPU cycles

User · Answer

try  ps huH p  lt PID OF U PROCESS gt    wc -l   or htop

User · Answer

Here is one command that displays the number of threads of a given process    ps -L -o pid  -p  lt pid gt    wc -l   Unlike the other ps based answers  there is here no need to substract 1 from its output as there is no ps header line thanks to the -o pid option

User · Answer

jvmtop can show the current jvm thread count beside other metrics

User · Answer

try  ps huH p  lt PID OF U PROCESS gt    wc -l   or htop

User · Answer

If you want the number of threads per user in a linux system then you should use  ps -eLf   grep  lt USER gt    awk    num     6   END   print num     where as  lt USER gt  use the desired user name

User · Answer

If you use   ps uH p  lt PID OF U PROCESS gt    wc -l   You have to subtract 1 to the result  as one of the lines  wc  is counting is the headers of the  ps  command

User · Answer

If you are trying to find out the number of threads using cpu for a given pid I would use   top -bc -H -n2 -p  lt pid gt    awk   if   9     0 0   amp  amp   1      0-9      print  1      sort -u   wc -l

User · Answer

To get the number of threads for a given pid     ps -o nlwp  lt pid gt    Where nlwp stands for Number of Light Weight Processes  threads   Thus ps aliases nlwp to thcount  which means that    ps -o thcount  lt pid gt    does also work   If you want to monitor the thread count  simply use watch     watch ps -o thcount  lt pid gt    To get the sum of all threads running in the system     ps -eo nlwp   tail -n  2   awk    num threads     1   END   print num threads

User · Answer

ps H p pid-id  H - Lists all the individual threads in a process  or   cat  proc pid-id status  pid-id is the Process ID  eg    Truncated the below output   root abc    cat  proc 8443 status Name    abcdd State   S  sleeping  Tgid    8443 VmSwap         0 kB Threads     4 SigQ    0 256556 SigPnd  0000000000000000

User · Answer

If you are trying to find out the number of threads using cpu for a given pid I would use   top -bc -H -n2 -p  lt pid gt    awk   if   9     0 0   amp  amp   1      0-9      print  1      sort -u   wc -l

User · Answer

Newer JDK distributions ship with JConsole and VisualVM  Both are fantastic tools for getting the dirty details from a running Java process  If you have to do this programmatically  investigate JMX

User · Answer

try  ps huH p  lt PID OF U PROCESS gt    wc -l   or htop

User · Answer

Newer JDK distributions ship with JConsole and VisualVM  Both are fantastic tools for getting the dirty details from a running Java process  If you have to do this programmatically  investigate JMX

User · Answer

My answer is more gui  but still within terminal  Htop may be used with a bit of setup   Start htop  Enter setup menu by pressing F2  From leftmost column choose  quot Columns quot  From rightmost column choose the column to be added to main monitoring output   quot NLWP quot  is what you are looking for  Press F10

User · Answer

JStack is quite inexpensive - one option would be to pipe the output through grep to find active threads and then pipe through wc -l   More graphically is JConsole  which displays the thread count for a given process

User · Answer

If you re looking for thread count for multiple processes  the other answers won t work well for you  since you won t see the process names or PIDs  which makes them rather useless  Use this instead  ps -o pid nlwp args -p  lt pid 1 gt   lt pid 2 gt       lt pid N gt   In order to watch the changes live  just add watch  watch ps -o pid nlwp args -p  lt pid 1 gt   lt pid 2 gt       lt pid N gt

User · Answer

ps -eLf on the shell shall give you a list of all the threads and processes currently running on the system  Or  you can run top command then hit  H  to toggle thread listings

User · Answer

The easiest way is using  htop   You can install  htop   a fancier version of top  which will show you all your cores  process and memory usage   Press  Shift H  to show all process or press again to hide it  Press  F4  key to search your process name   Installing on Ubuntu or Debian   sudo apt-get install htop   Installing on Redhat or CentOS   yum install htop dnf install htop       On Fedora 22  releases    If you want to compile  htop  from source code  you will find it here

User · Answer

My answer is more gui  but still within terminal  Htop may be used with a bit of setup   Start htop  Enter setup menu by pressing F2  From leftmost column choose  quot Columns quot  From rightmost column choose the column to be added to main monitoring output   quot NLWP quot  is what you are looking for  Press F10

[linux] How can I monitor the thread count of a process on linux?

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