fkarakas / golang-pprof-linux-signal

golang activate pprof with linux signal USR1

Goal

Activate pprof endpoint with the linux signal USR1 (shutdown with USR2)

Why ?

Because you need to investigate an issue on a running GO program on production.

Of course, you can always activate pprof endpoint but this approch has 2 issues :

• security: it is not recommended to expose an endpoint if you don't really need, most of security breach are comming from web server running in background and exposing internal information about a program.
• performance: even if the pprof sampling will not make a big impact on the running program, it has an impact on the performance.

Linux signal

To interact with the go process we can use linux signal USR1 and USR2 which can be used as custom signal

So to activate the pprof:

$ kill -USR1 $PID
$ curl http://localhost:6060/debug/pprof/goroutine\?debug\=2
goroutine 14 [running]:
runtime/pprof.writeGoroutineStacks(0x1496a00, 0xc0001921c0, 0xc000078840, 0x0)

And to deactivate the pprof:

$ kill -USR2 $PID
$ curl http://localhost:6060/debug/pprof/goroutine\?debug\=2
curl: (7) Failed to connect to localhost port 6060: Connection refused