duplicate FDs

[justinpryzby]

I've suspected a continuing problem with FDs [0], and just discovered that files are sometimes opened multiple times.
I suspect this is a symptom of some underlying problem.

$ sudo ls -l /proc/pgrep supervisord/fd |grep eutr
lr-x------ 1 root root 64 Dec 5 20:34 15 -> /home/telsasoft/server/log/log.eric_eutran
l-wx------ 1 root root 64 Dec 5 20:34 17 -> /home/telsasoft/server/log/log.eric_eutran
lr-x------ 1 root root 64 Dec 5 20:36 83 -> /home/telsasoft/server/log/log.eric_eutran

A few seconds later:
$ sudo ls -l /proc/pgrep supervisord/fd |grep eutr
lr-x------ 1 root root 64 Dec 5 20:34 15 -> /home/telsasoft/server/log/log.eric_eutran
l-wx------ 1 root root 64 Dec 5 20:34 17 -> /home/telsasoft/server/log/log.eric_eutran

There is only one process, with:
stdout_logfile = /home/telsasoft/server/log/log.%(program_name)s

Note that it does fork multiple child processes.

I suspect this has caused service outages, and I also suspect I'll find more of these. Let me know what more information I can collect next time.

This might be related to other issues (#984, #1110).

[0] #807 (comment)