[OpenSIPS-Users] Chasing down unreleased memory

[Jock McKechnie]

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"