Cache manager occasionally stops deleting cached files

[Maxim Dounin]

Hello!

On Fri, Feb 19, 2016 at 08:00:54AM -0500, vedranf wrote:

[...]

> Thanks, I'll dig deeper. I do have 3rd party modules and there are
> occasional messages such as "worker process exited on signal 11", but they
> are rare, i'll try to figure out what causes them, but it'll take time.

So the problem with cache is clear - one worker crash is usually 
enough to stop nginx from removing cache items based on max_size 
sooner or later.  You have to further debug crashes to fix things.

> However, now that this already happens, is it possible so somehow unlock all
> entries and start clean, but without removing all cached content? Or
> alternatively, can I delete the locked files manually as a workaround?

You need nginx to reload its cache matadata (as stored in 
keys_zone).  This can be done either with restart or binary 
upgrade to the same nginx binary, see:

http://nginx.org/en/docs/control.html#upgrade

There is no need to delete cache files.

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