How to know the number of active threads in Puma

Question

I am trying to see the number of active puma threads on my server.

I can not see it through ps:

$ ps aux | grep puma
healthd   2623  0.0  1.         


        

Answer 1

Using ps and wc to count puma threads:

ps --no-headers -T -C puma | wc -l

The string "puma" can be replaced as desired. Example, count bash threads:

ps --no-headers -T -C bash | wc -l

On my system that outputs:

9

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The code in the question, ps aux | grep puma, has a few grep related problems:

1. It returns grep --color=auto puma, which isn't a puma thread at all.
2. Similarly any util or command with the string "puma", e.g. a util called notpuma, would be matched by grep.