Hello all and happy new year,

I have some new information to share regarding this issue. I believe the previous metrics I sent to the list might not be indicative of the way the problem manifests. Here's what I believe so far:

- Issue is exacerbated (or manifests) during moderate-to-high cps, or grows linearly with total traffic processed since last restart

- shm stats show a lot of memory consumed by sip_msg_shm_clone

- also reproduced this time on bullseye with kamailio 5.5.3

Here's some more meaningful stats taken at more appropriate times (i.e. after more traffic has been processed) than the previous ones. These two kamailio instances have identical configuration and traffic patterns:

- https://pastebin.com/gHa803kB for kamailio 5.5.3 showing high sip_msg_shm_clone on debian bullseye

- https://pastebin.com/JbcZbbSQ for kamailio 5.4.6 on debian buster

There is still DMQ use for these instances despite the version mismatch. Unfortunately I can't migrate all DMQ nodes to 5.5.x at this time, not unless I can have assurances that it is DMQ that causes this issue with shm memory exhaustion...

After shmem was exhausted on 5.5.3, it stopped processing traffic. I issued a kamctl trap at that time but I'm assuming the backtrace won't show much except for the inability to allocate shm? If you think the backtrace at that point would be useful in any way, let me know and I'll try to share it privately. In case it isn't useful, what other debugging information can be gathered to dissect this issue? Thanks!

BR,

George

On Wed, 30 Jun 2021 at 19:20, Daniel-Constantin Mierla <miconda@gmail.com> wrote:

Hello,

for the sake of completion: the autoexpire should clean the items if they are not used during the expiration interval. If you want to get them deleted after first expiration interval always, see the updateexpire attribute for htable modparam.

Also, note that replication should be done only between Kamailio instances with same major version, because there can be internal differences between major versions that can lead to unexpected behaviour. In other words, if you replicate, doing between two kamailio with version 5.5.x or between two kamailio with version 5.4.x, but not between a kamailkio 5.5.x and a kamailio 5.4.x.

The total amount of used memory in the stats file for 5.5 does not seem to be high as a rough estimation. The highest by module is in htable, but it is around 20MB. Maybe you took the stats too early, quickly after a restart?

Cheers,
Daniel

On 30.06.21 17:20, George Diamantopoulos wrote:
Hello Daniel,

Thanks for the feedback. I think I might have been too quick to blame htable for this behaviour. In fact, version 5.4 seems to consume more memory than 5.5 (175129776 bytes vs 20581096), which makes sense since it has been running for longer (I missed the extra digit previously).

So I'm not sure htable is to blame. On the other hand, I don't see any other modules using up too much of shmem either, so maybe memory stats can't provide the answer here?

To answer your question, though, I do use DMQ and both tables that use it have autoexpire set to the same value on both 5.4 and 5.5:

/etc/kamailio# grep dmq kamailio-module-params.cfg
modparam("dmq", "server_address", "sip:172.30.43.1:5090")
modparam("dmq", "notification_address", "sip:dmq.services.mydomain.com:5090")
modparam("dmq", "multi_notify", 1)
modparam("htable", "enable_dmq", 1)
modparam("htable", "htable", 'cid2hi=>size=8;autoexpire=600;dmqreplicate=1')
modparam("htable", "htable", 'xcid2count=>size=8;autoexpire=600;dmqreplicate=1')
On Wed, 30 Jun 2021 at 17:43, Daniel-Constantin Mierla <miconda@gmail.com> wrote:
Hello,

do you replicate items in the htable via dmq? Does the htable have autoexpire value set?

Cheers,
Daniel

On 30.06.21 13:54, George Diamantopoulos wrote:
Forwarding my reply to the list, using gmail's reply button set Henning as the sole recipient :-\

---------- Forwarded message ---------
From: George Diamantopoulos <georgediam@gmail.com>
Date: Sat, 26 Jun 2021 at 02:25
Subject: Re: [SR-Users] Possible memory leak on 5.5.x (new)?
To: Henning Westerholt <hw@skalatan.de>

Hello Henning,

Thanks for your reply. Here's what has come up after a few hours:

shm55: https://pastebin.com/h9JCePmc

shm54: https://pastebin.com/Nx5xEEnA

It seems to me htable is the culprit? Are you seeing anything different? 54 has been running for 77020 seconds, 55 for 28521 (significantly less).

I'm going to turn it off until we figure something out...

BR,

George

On Fri, 25 Jun 2021 at 18:17, Henning Westerholt <hw@skalatan.de> wrote:

Hello,

Good observation. Please run the memory statistics CLI commands to get more hints about the module that might cause it (as per below link). Then please report more details. If you can point to a particular module, you can also open an issue on our tracker.

https://www.kamailio.org/wiki/tutorials/troubleshooting/memory

Cheers,

Henning

From: sr-users <sr-users-bounces@lists.kamailio.org> On Behalf Of George Diamantopoulos
Sent: Friday, June 25, 2021 4:53 PM
To: Kamailio (SER) - Users Mailing List <sr-users@lists.kamailio.org>
Subject: [SR-Users] Possible memory leak on 5.5.x (new)?

Hello all,

I'm still investigating the (most likely non-kamailio-related) memory leak of my previous message to the list, there have been no developments so far. I'll update if anything changes.

This concerns a new finding which seems to affect kamailio 5.5.x. I have two kamailio instances receiving the same traffic via round-robin. I upgraded only one of them to 5.5.1 and left the other to 5.4.6 as I feared of any issues arising. I was lucky to do so, because with identical configuration, 5.5.x seems to run out of SHM very quickly. Here are links to graphs produced by our monitoring system:

Old kamailio (no memory leak): https://pasteboard.co/K8fVBiD.png

New kamailio (possible leak): https://pasteboard.co/K8fVS9N.png

The configuration uses mtree, htable, vars and vns extensively. Has anyone come across anything similar? Let me know if I can provide any further information to help disect this. Thanks!

BR,

George
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Daniel-Constantin Mierla -- www.asipto.com
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Daniel-Constantin Mierla -- www.asipto.com
www.twitter.com/miconda -- www.linkedin.com/in/miconda