As reported by a developer today, poppy service at upload.ubuntu.com started failing uploads, found at log lines like:
2013-07-11 13:43:20+0000 [FTP (ProtocolWrapper),113355,72.174.242.143] Unexpected error attempting to open file for upload:
2013-07-11 13:43:20+0000 [FTP (ProtocolWrapper),113355,72.174.242.143] Logged OOPS id 151328256: IOError: [Errno 24] Too many open files: '/tmp/tmpBP2TZK/linux-mako_3.4.0-3.16.dsc'
Digging into the process opened FDs clearly shows lockfile not being closed -> http://paste.ubuntu.com/5865029/, see there repeated lines like e.g.:
l-wx------ 1 lp_upload lp_upload 64 2013-07-11 13:54 1001 -> /srv/launchpad.net/ubuntu-queue/incoming/.lock
l-wx------ 1 lp_upload lp_upload 64 2013-07-11 13:54 1002 -> /srv/launchpad.net/ubuntu-queue/incoming/.lock
l-wx------ 1 lp_upload lp_upload 64 2013-07-11 13:54 1003 -> /srv/launchpad.net/ubuntu-queue/incoming/.lock
l-wx------ 1 lp_upload lp_upload 64 2013-07-11 13:54 1004 -> /srv/launchpad.net/ubuntu-queue/incoming/.lock
This may be related to https://bugs.launchpad.net/launchpad/+bug/156795.
