Cache manager occasionally stops deleting cached files

[Maxim Dounin]

Hello!

On Thu, Feb 25, 2016 at 05:46:32AM -0500, vergil wrote:

> vedranf Wrote:
> -------------------------------------------------------
> > Hello,
> > 
> > I'm having an issue where nginx (1.8) cache manager suddenly just
> > stops deleting content thus the disk soon ends up being full until I
> > restart it by hand. After it is restarted, it works normally for a
> > couple of days, but then it happens again. Cache has some 30-40k
> > files, nothing huge. Relevant config lines are:

[...]

> We have the same problem, but i'm not sure, that this is caused by often
> nginx restarts.

This particular case was traced to segmentation faults, likely 
caused by 3rd party modules.

[...]

> Also, i think it's somehow related to write connection leak. (see image
> link)
> 
> https://s3.eu-central-1.amazonaws.com/drive-public-eu/nginx/betelgeuse_nginx_connections.PNG

[...]

> As you see write connections continuously grows. (When we had to power off
> the machine it's reached ~60k).
> 
> For counting nginx connections we use standard http_stub_status_module.
> 
> I think that nginx "reference counter" could be broken, because total
> established TCP connection remains the same all the time.

Writing connections will grow due to segmentation faults as well, 
so you are likely have the same problem.  See basic 
recommendations in my initial answer in this threads.

-- 
Maxim Dounin
http://nginx.org/