[Bug 999915] Re: High CPU usage on broken request to apt-cacher-ng

[Marc Deslauriers]

Debdiff looks good, ACK.
I've uploaded it to precise-proposed with a slight version change for processing by the SRU team. Thanks!

-- 
You received this bug notification because you are a member of Ubuntu
Sponsors Team, which is subscribed to the bug report.
https://bugs.launchpad.net/bugs/999915

Title:
  High CPU usage on broken request to apt-cacher-ng

Status in “apt-cacher-ng” package in Ubuntu:
  Fix Released
Status in “apt-cacher-ng” source package in Precise:
  In Progress

Bug description:
  I manage a server with apt-cacher-ng, I noted an CPU increase to 100%
  usage without any aparent reason, it sometimes even freezes so I have
  to restart the service every time this happen, but sometimes this was
  about twice a day...

  I decided to debug it to see what was happening so I follow the steps
  in http://www.unix-ag.uni-kl.de/~bloch/acng/html/troublefaq.html in
  the point 9.5, I compiled the source with DEBUG flag and run it.

  The next day I ended with a 2.8GB apt-cacher.err and a infinite loop of:
  - target: ooo vs archive.ubuntu.com, ports: 80 vs 80, good config: 0 [139752724489984 at dlcon.cc:831|139753806664752]
  - >> dlcon::SetupJobConfig [139752724489984 | 139753806664752]
  - << dlcon::SetupJobConfig [139752724489984 | 139753806664752]

  Some time ago the desktops computers where configured using the following source line:
  deb http://serverip:3142/ooo hardy main
  /ooo was an alias to a ppa, the alias was removed from the server, and all the new desktops where configured using Acquire::http { Proxy "http://servername:3142"; };
  but some of the older machines keep the old format...

  I attach a fragment of the log where it start the infinite loop, note
  the time... it's an 8 seconds fragment log with 130500+ lines.

  I have tracked the computer that was sending the request and change
  the source.list, but this should be fixed in apt-cacher-ng, and handle
  the request a little more graceful.

  --

  SRU Justification:

  [Impact]
  * Users of apt-cacher-ng may see CPU usage of 100% due to a infinite loop in the code.
  * The fix for this package is already present in quantal and beyond, and the author has provided the patch on this bug.

  [Test Case]
  Use apt-cacher-ng and occasionally one may hit this infinite loop error depending on the source.list configuration.

  [Regression Potential]
  * Small change, present in quantal/raring and upstream.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/apt-cacher-ng/+bug/999915/+subscriptions