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

Okay, to follow up. I still cannot reproduce this in a lab
environment, but I have implemented a way of doing what Alex described
on the production machine. I run two instances of Squid with the same
config and switch the transparent proxy out by changing the redirect
rules in iptables. The second instance is running without a cache_dir
though, to prevent the possibility of two instances sharing the same
directory and running amok. If requested, I can create a second
cache_dir for the second instance to mimic the config entirely.

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.

Where shall we go from here? Given that I can switch between the
instances, impacting performance on the production box is not of huge
concern now, so I can run the second instance under Valgrind, or bump
up the debug logging, or whatever would be helpful.

As an aside, I've been reading some of the code pointed at by traces
I've got, and I've stumbled upon the fact that nearly every caller of
StoreEntry::replaceHttpReply will leak HttpReply objects if the
internal mem_obj pointer of a StoreEntry is set to NULL. There's a
critical log message that occurs in this situation which I have not
seen, so I can conclude that this is not the issue I am seeing, but
it's an issue nonetheless. If there's interest, I'll submit a patch
for this issue.

Many thanks,

Nathan.

--
Nathan Hoad
Software Developer
www.getoffmalawn.com
On Sat, Dec 14, 2013 at 8:11 PM, Nathan Hoad <nathan_at_getoffmalawn.com> wrote:
> On Fri, Dec 13, 2013 at 10:33 PM, Eliezer Croitoru <eliezer_at_ngtech.co.il> wrote:
>> Hey Nathan,
>>
>> I am looking for more details on the subject in hand in the shape of:
>> Networking Hardware
>
> Straight out of lspci:
>
> 02:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5722
> Gigabit Ethernet PCI Express
> 03:01.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5703
> Gigabit Ethernet (rev 10)
>
> Two network cards - one for internal traffic, the other for external.
>
>> Testing Methods
>
>  - a mixture of direct and intercepted HTTP and HTTPS traffic, hitting
> the configured ICAP server and not.
>  - both valid and invalid upstream SSL certificates, hundreds of
> concurrent requests from a single client
>  - thrashing Squid with thousands of connections that are aborted
> after 800ms, running for ~30-40 seconds at a time.
>  - currently I'm putting the week's access.log through Squid to see if
> that triggers it, for a poor approximation of the traffic.
>
>> Is it a SMP squid setup?
>  - both SMP (2 workers) and non-SMP.
>
>> In the case you use a 32bit system which is limited to how much ram??(I
>> remember something about a windows nt with 64GB).
>
>  - This particular host has 3gb of RAM. Previously running a non-SMP
> Squid 3.2.13 instance and according to logs, maxed out at ~500mb of
> resident after running for hours or days at a time, with a 220mb
> cache_mem. Now, however the memory usage grows to 900mb in ~40
> minutes, and typically reaches 1.5gb in ~4 hours. We have a ulimit in
> place to kill it once it hits 1.5gb, but prior to putting that in
> place it typically reached 2gb.
>
>>
>> If you can provide more details I will be happy to try and test it.
>>
>> Thanks,
>> Eliezer
>
> If there's any other information you think may be useful, feel free to ask.