Problems with Ubuntu 12.04.2 LTS

[schmilblick]

Unfortunatly we havent had the time to investigate further, but we managed to find a case where johnny (or rather the runserver) goes crazy and hogs over all 16 GB of RAM and all swap on our dev server. The server freezes with the message "task jbd2/dm-0-8:584 blocked for more than 120 seconds." and becomes unresponsive.

We spent the rest of that day thinking that the disk was about to die and let it do a fsck ... -cc over night. When no errors where found we started looking in to the Django project specifics. Some parts of the project worked fine, but one page generated the crash described above.

I can reproduce it in my dev env pretty easy, but its hard to provide any more information since its project specific. When I remove johnny-cache from the project, everything works fine.

While this might not be a johnny-cache problem but something else underneath, i still thought it would be worth mentioning here.

[kevinastone]

I run Ubuntu 12.04.2 LTS on dev + staging + production systems (mostly smaller EC2 instances) that incorporate Johnny Cache and I haven't seen this issue.

[jself]

You added the LocalStoreClearMiddleware? That's the only thing that I can think of that would cause an app server to increase in memory footprint via johnny cache (that or a gargantuan query being returned from the database and being temporarily stored there)
When a query executes, johnny evaluates it all and puts it into a thread local storage (in order to make it cacheable/support transactions/etc)
Hope this helps