[DRE-maint] Bug#794820: ruby-rack: High CPU usage in "apache -k start" processes with phusion passenger

[Andy Smith]

Package: ruby-rack
Version: 1.4.1-2.1+deb7u1
Severity: normal

Dear Maintainer,

After upgrading ruby-rack package from 1.4.1-2.1 to 1.4.1-2.1+deb7u1,
high CPU usage is observed with the two apache "start" processes.
Between them they are trying to use 100% CPU forever.

This problem goes away when ruby-rack package is downgraded to 1.4.1-2.1
again.

The app being run here is puppet master, but the only package being
changfed is ruby-rack.

An strace of the apache processes showed them to be just waiting on a
read of fd #89 (a pipe), but I expect they are multi-threaded so this
was not useful.

Apache MPM in use is prefork, and phusion passenger

-- System Information:
Debian Release: 7.8
  APT prefers oldstable-updates
  APT policy: (500, 'oldstable-updates'), (500, 'oldstable')
Architecture: i386 (i686)

Kernel: Linux 3.2.0-4-686-pae (SMP w/1 CPU core)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages ruby-rack depends on:
ii  ruby                          1:1.9.3
ii  ruby1.8 [ruby-interpreter]    1.8.7.358-7.1+deb7u3
ii  ruby1.9.1 [ruby-interpreter]  1.9.3.194-8.1+deb7u5

ruby-rack recommends no packages.

ruby-rack suggests no packages.

-- no debconf information