Leaking pipe handles on SIGUSR2 #182
Description
This may be a simple puma configuration error, since I'm just starting out with puma, but I haven't found anything in the documentation that mentions this.
I'm running puma 1.6.3 on a centos 6 server using MRI 1.9.3p327 with rails 3.2.11. My puma config file looks like this:
environment "staging"
bind "unix:///deploy_path/staging/shared/sockets/puma.sock"
threads 1,4
pidfile "/deploy_path/staging/shared/pids/puma.pid"
on_restart do
ActiveRecord::Base.connection.close
end
Alternating between checking used filehandles and restarting puma in the shell I get the following output:
[user@server deploy_path]$ ps ax | grep puma
23302 pts/0 Sl+ 0:02 ruby /deploy_path/staging/shared/bundle/ruby/1.9.1/bin/puma -C /deploy_path/staging/current/config/puma.conf
[user@server deploy_path]$ lsof -p 23302 | grep pipe
ruby 23302 user 3r FIFO 0,8 0t0 3049293 pipe
ruby 23302 user 4w FIFO 0,8 0t0 3049293 pipe
ruby 23302 user 9r FIFO 0,8 0t0 3049304 pipe
ruby 23302 user 10w FIFO 0,8 0t0 3049304 pipe
ruby 23302 user 11r FIFO 0,8 0t0 3049305 pipe
ruby 23302 user 12w FIFO 0,8 0t0 3049305 pipe
ruby 23302 user 14r FIFO 0,8 0t0 3049308 pipe
ruby 23302 user 15w FIFO 0,8 0t0 3049308 pipe
[user@server deploy_path]$ kill -USR2 23302
[user@server deploy_path]$ lsof -p 23302 | grep pipe
ruby 23302 user 3r FIFO 0,8 0t0 3049452 pipe
ruby 23302 user 4w FIFO 0,8 0t0 3049452 pipe
ruby 23302 user 9r FIFO 0,8 0t0 3049304 pipe
ruby 23302 user 10w FIFO 0,8 0t0 3049304 pipe
ruby 23302 user 11r FIFO 0,8 0t0 3049305 pipe
ruby 23302 user 14r FIFO 0,8 0t0 3049308 pipe
ruby 23302 user 15w FIFO 0,8 0t0 3049308 pipe
ruby 23302 user 16r FIFO 0,8 0t0 3049461 pipe
ruby 23302 user 17w FIFO 0,8 0t0 3049461 pipe
ruby 23302 user 18r FIFO 0,8 0t0 3049462 pipe
ruby 23302 user 19w FIFO 0,8 0t0 3049462 pipe
ruby 23302 user 20r FIFO 0,8 0t0 3049463 pipe
ruby 23302 user 21w FIFO 0,8 0t0 3049463 pipe
[user@server deploy_path]$ kill -USR2 23302
[user@server deploy_path]$ lsof -p 23302 | grep pipe
ruby 23302 user 3r FIFO 0,8 0t0 3049530 pipe
ruby 23302 user 4w FIFO 0,8 0t0 3049530 pipe
ruby 23302 user 9r FIFO 0,8 0t0 3049304 pipe
ruby 23302 user 10w FIFO 0,8 0t0 3049304 pipe
ruby 23302 user 11r FIFO 0,8 0t0 3049305 pipe
ruby 23302 user 14r FIFO 0,8 0t0 3049308 pipe
ruby 23302 user 15w FIFO 0,8 0t0 3049308 pipe
ruby 23302 user 16r FIFO 0,8 0t0 3049461 pipe
ruby 23302 user 17w FIFO 0,8 0t0 3049461 pipe
ruby 23302 user 18r FIFO 0,8 0t0 3049462 pipe
ruby 23302 user 20r FIFO 0,8 0t0 3049463 pipe
ruby 23302 user 21w FIFO 0,8 0t0 3049463 pipe
ruby 23302 user 22r FIFO 0,8 0t0 3049540 pipe
ruby 23302 user 23w FIFO 0,8 0t0 3049540 pipe
ruby 23302 user 24r FIFO 0,8 0t0 3049541 pipe
ruby 23302 user 25w FIFO 0,8 0t0 3049541 pipe
ruby 23302 user 26r FIFO 0,8 0t0 3049542 pipe
ruby 23302 user 27w FIFO 0,8 0t0 3049542 pipe
I'm not opening connections to anywhere other than activerecord at the moment from within my app.
It looks to me like puma is opening pipes to communicate with itself (between threads?) and the pipes don't get closed after a restart. Checking with ps -efL does show that the old threads die on a SIGUSR2.