Re: [squid-users] Squid 3.3 is very aggressive with memory

On 18/12/2013 6:54 p.m., Alex Rousskov wrote:
> On 12/16/2013 10:24 PM, Nathan Hoad wrote:
>
>> While running under this configuration, I've confirmed that memory
>> usage does go up when active, and stays at that level when inactive,
>> allowing some time for timeouts and whatnot. I'm currently switching
>> between the two instances every fifteen minutes.
>>
>> Here is a link to the memory graph for the entire running time of the
>> second process, at 1 minute intervals:
>> http://getoffmalawn.com/static/mem-graph.png. The graph shows memory
>> use steadily increasing during activity, but remaining reasonably
>> stable during inactivity.
>
> I agree that this looks like a memory leak, but (in general) it could
> also be some kind of memory pooling or cache entry accumulation.
>
>
>> Where shall we go from here?
>
>
> I recommend the following next steps:
>
> 1. Set "memory_pools off".
>
> 2. Disable all caching with "cache deny all".
>
> Do you see as similar memory growth pattern after the above two steps?
>
> * If yes: Time for valgrind or ALL,9 debugging. I can help you make that
> choice if needed. You can actually do those things now, without doing
> steps 1 and 2 first, but valgrind and log analysis take time so if we
> can avoid it by eliminating false positives and/or simplifying the
> setup, we should do that first...
>
> * If no: Try re-enabling caching, but using smaller memory [and disk?]
> cache sizes so that a cache gets and stays _full_ way before you run out
> of RAM. This will eliminate cache index growth as a suspect. If your
> disk cache is full already or uses Rock store, then this applies to
> memory cache only. Do you see as similar memory growth pattern after
> re-enabling caching? Are your caches full?

The other possibility is username cache in 3.3, since the credentials
used to be tied to the HTTP request details they came from. We had a
memory "leak" bug a while back where the credentials reference to that
request would hold up releasing of the entire transaction state memory.

Amos
Received on Wed Dec 18 2013 - 06:33:54 MST