how do you view all threads running on Linux?

Question

I've used 'top', but I need a tool that can give me an arbitrary-time history of threads that have executed on my system (CentOS 5.4)?

Answer 1

ps -eLf will give you a list of all the threads and processes currently running on the system.

However you ask for a list of all threads that HAVE executed on the system, presumably since some arbitrary point in the past - are you sure that is what you mean? You could run ps as a cron job and poll the system every X minutes, but you would miss threads that were born and died between jobs. You would also have a huge amount of data to deal with.

Answer 2

I am not aware of a logging solution in a single application. However, working with the more general logging / monitoring framework Zabbix I created the following definition to collect data on threads used by the application I wanted to monitor:

UserParameter=myapp.threads,ps --no-headers -L -p$(pgrep -x myapp)|wc -l

This one-line entry in the config makes Zabbix report, under the token 'myapp.threads' the number of threads seen each time the snippet is run. This picks up the process id via a first call to pgrep, then lists all threads using ps -L and counts them via wc -l.

Not the most elegant solution but it got the job done in a few minutes. Now, with Zabbix databasing and reporting, I can look at this through time. Of course, you probably wouldn't want to install Zabbix just for this.

Answer 3

use the ps command.

Answer 4

ps ax | grep Apache

just replace Apache with the process you're looking for

Answer 5

I think Linux has process auditing support. You might be able to get that set up to log every thread-creation. I don't know how to do this; I've never wanted to add overhead to kernel functions that are supposed to be fast. :/

Answer 6

lsof is a great utility to list open files and threads

Answer 7

run top, then hit 'H' to toggle thread listing

Answer 8

I like htop. It's like top, but colour coded and with more features.

lsof is good if you want something more advanced. Here's an excellent lsof tutorial.

Answer 9

See sar(1) by Sebastien Godard.