[OpenSIPS-Users] Chasing down unreleased memory

Mon Oct 1 14:14:36 EDT 2018

Greetings;

I should have done this last week but, to be honest, it just didn't
occur to me. I pulled the compression module out (and commented out
mc_compact()) and re-ran my tests and the memory usage was massively
lower (losing 100k of memory per minute vs 3-5MB/minute) and within a
few minutes of calling ceasing almost all of the memory was released
(went from 42MB down to 3.8MB within 6 minutes).

So it appears that there's something leaking in the compression module.

I'm going to poke around a few more tests (include compression.so
without actually calling it, etc) but I wanted to pass this on as
there appears to be a bug that needs addressing.

Is there anything I can provide that might be useful in debugging this?

As always, thank you for your help.

 - Jock

On Fri, Sep 21, 2018 at 8:12 AM, Jock McKechnie
<jock.mckechnie at gmail.com> wrote:
> Thank you very much, Răzvan;
>
> We are using the compression module for mc_compact(). We use SIP
> headers for passing around data (don't ask) and the compact headers
> are mandatory or else we hit MTU/fragmentation problems. We're on the
> cusp of moving to SIP/TCP but haven't gotten there quite yet.
> The mc_compact() lives in the main route[1] block and is simply this, in whole:
>     mc_compact("P-Asserted-Identity|Remote-Party-ID|X-UCID");
>
> And my apologies for not including the shm dump segment - please find it below.
> https://pastebin.com/itSTER7Y
>
> Let me know what else I can provide, this is fairly easy to replicate
> (although it takes about an hour of runtime pummeling it to get nice
> easy to read dumps). Thank you, again, very much.
>
>  - Jock
>
> On Fri, Sep 21, 2018 at 3:01 AM, Răzvan Crainea <razvan at opensips.org> wrote:
>> Hi, Jock!
>>
>> I think you are actually heating two memory leaks: one in private memory and
>> one in shared memory.
>> In the memory dump you sent I can spot a pkg mem related to (I believe) the
>> compression module. Can you tell me what functions of the compression module
>> you are using and what flags are you using for them?
>>
>> Besides that, you claim there is a shared memory leak as well. Can you send
>> us the logs for the shared memory? They are dumped by the first process
>> (attendant) and should start with the string "Memory status (shm):". Can you
>> post those logs as well?
>>
>> Best regards,
>> Razvan
>>
>>
>> On 9/20/18 9:43 PM, Jock McKechnie wrote:
>>>
>>> Greetings OpenSIPS gurus;
>>>
>>> I've run into an issue that I'm not making any real headway with on my
>>> own. I have an OpenSIPS 2.4.2 running on CentOS7 that does not appear
>>> to be releasing the bulk of its shared memory when calls die off.
>>> Eventually OpenSIPS runs itself out of shared memory and goes beserk
>>> when it can't reclaim memory for new transactions, or I've also seen
>>> the kernel oomkiller take it down.
>>>
>>> The setup is, as mentioned, a 2.4.2 which has a chunk of perl living
>>> on its back that handles some API directed call decisions. Because of
>>> the inevitable delay in the API lookups I am running a large number of
>>> threads (100) to ensure that I don't start dropping packets under high
>>> levels of load (50 CPS+ - until I bumped children counts up I was
>>> seeing packets being ignored which got the End User very excitable). I
>>> appreciate having lots of children amplifies memory usage but my
>>> belief is during regular load on our side (~6000 calls at ~30 - 40CPS)
>>> I should have a full day's runtime easily w/o running into problems.
>>> The issue is that because the memory is not released overnight it
>>> starts the next day with half its shared memory gone, and then things
>>> go to pot the next day when it runs through all its remaining shared
>>> memory.
>>>
>>> I have it configured for a very large (I think) amount of memory to
>>> attempt to compensate short-term - 2048MB shared memory, 128MB package
>>> memory. This is not a well thought-out number, just me throwing RAM at
>>> the problem. (For reference this is on a VM running with 4 cores and
>>> 4096MB of RAM)
>>>
>>> I have graphed the memory stats out of the FIFO, after enabling
>>> memstats and DBG_MALLOC/etc. The graphs can be found here:
>>> https://imgur.com/a/oapKYJW
>>>
>>> You'll see that the first graph, the main shmem:, shows the usage gets
>>> tied up and remains after calls die off (these examples run for 20
>>> minutes after the calls stopped - but I can leave it overnight and the
>>> shmem: usage won't drop). This being said, the other graphed modules
>>> show that it releases memory correctly after calls quit like they
>>> should. None of the other modules graphed (eg, _all_ of the modules I
>>> was using in OpenSIPS) showed no significant usage and I've omitted
>>> them.
>>>
>>> Interesting that the 'perl' module shows no stats ever which makes me
>>> wonder if the stats on this module works. I am not storing anything
>>> inside perl, besides lots of local session variables, and all channel
>>> variables are pushed back into OpenSIPS AVPs, but I assume there must
>>> be some memory overhead, although it may not significantly change.
>>>
>>> When I shut OpenSIPS down I get child dumps like the following: (I've
>>> included only one for brevity, but they're all much of a muchness)
>>> https://pastebin.com/KG2qxxBa
>>>
>>> If I'm reading this right (and there's a strong possibility I'm
>>> misunderstanding what I'm looking at) the memory is tied up in io_wait
>>> and the parser. I'm not sure what this signifies, however.
>>>
>>> So I guess what I'm asking is:
>>> Am I understanding what I'm looking at correctly and that OpenSIPS is
>>> not releasing its shared memory which causes it to run out of memory
>>> quicker the following day? (Which lines up with the symptoms of
>>> shorter runtimes before failure)
>>>
>>> Based on the dumps where should I look for the source of this issue?
>>>
>>> Finally, and unrelated to the above, I attempted to mail the official
>>> OpenSIPS peeps to talk about paid support but none of the 'contact us'
>>> submits appear to work - when I click on the submit button it changes
>>> shade but does not appear to act. Certainly I never received any
>>> response. If there was a direct eMail address I could send to that
>>> would be preferable.
>>>
>>> As always, my thanks for your time.
>>>
>>>   - Jock
>>>
>>> PS -
>>> List of modules I'm using in this config:loadmodule "signaling.so"
>>> loadmodule "sl.so"
>>> loadmodule "tm.so"
>>> loadmodule "rr.so"
>>> loadmodule "maxfwd.so"
>>> loadmodule "textops.so"
>>> loadmodule "uri.so"
>>> loadmodule "mi_fifo.so"
>>> loadmodule "siptrace.so"
>>> loadmodule "sipmsgops.so"
>>> loadmodule "dialog.so"
>>> loadmodule "uac_auth.so"
>>> loadmodule "uac.so"
>>> loadmodule "perl.so"
>>> loadmodule "acc.so"
>>> loadmodule "proto_hep.so"
>>> loadmodule "proto_udp.so"
>>> loadmodule "compression.so"
>>>
>>> _______________________________________________
>>> Users mailing list
>>> Users at lists.opensips.org
>>> http://lists.opensips.org/cgi-bin/mailman/listinfo/users
>>>
>>
>> --
>> Răzvan Crainea
>> OpenSIPS Core Developer
>>   http://www.opensips-solutions.com
>>
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