[erlang-questions] Fwd: phantom ports in erlang:ports()

[Tim Watson]

Hi guys - can anyone answer this (below) please?

Begin forwarded message:

> From: Matthias Radestock <matthias@REDACTED>
> Subject: phantom ports in erlang:ports()
> Date: 12 November 2012 18:37:47 GMT
> To: erlang-questions@REDACTED
> 
> I've got a customer system, running R15B02, which encountered system_limit errors when accepting tcp connections.
> 
> 'lsof' indicates that there are just a few hundred file descriptors in use. However, erlang:ports() returns 1010 entries. For the majority of these ports:
> - erlang:port_info(Port) returns 'undefined'
> - port_close(Port) fails with 'badarg'
> - exit(Port, die) doesn't make them go away
> 
> These ports have been in that state for days.
> 
> Does anybody have any clue what's going on here?
> 
> Is there any way to find out more about these ports? Looks like ctrl-c'ing in the emulator shell would allow me to get more info with the 'o' option. Unfortunately the customer's emulator is running detached, so that won't work.
> 
> Regards,
> 
> Matthias.