[SR-Users] rtpengine in stateless kamailio

Richard Fuchs rfuchs at sipwise.com
Wed Jan 2 14:44:40 CET 2019

On 02/01/2019 07.45, Yuriy Gorlichenko wrote:
> Hi!
> Happy new year to all!!!
> Look like I am first in this year wit hthe questions in this list :-).
> I'm using stateless kamailio and RTPengnine to build some kind of the 
> stateless cluster
> I found that kamailio keeps some data  in the SHMEM in case of using 
> RTPengine module even if it is not a rtpengine_manage function but 
> offer/answer/delete
> In this case if INVITE (offer) handled by 1-st kamailio in my cluster, 
> and BYE/CANCEL handled by second kamailio in the cluster - 1-st 
> kamailio (which has been used for offer) will hase kinda internal 
> "memory leak" (in SHMEM it never decrased)
> At the rtpengine module source I found some transation dependencies 
> for the rtpengine_manage function but did not find for the 
> offer/answer/delete
> I supposed these 3 functions just sending requests to the rtpnegine 
> with keys and not storing anything
> So my question - is it possible to use RTPengine module in stateless 
> way to avoid internal "memory leak" because in my scenario I have big 
> chance never receive  BYE/CANCEL on the machine that started handle 
> particular call

This is probably the module-internal hash table that is used to make 
sure that signalling relating to the same call is always sent to the 
same rtpengine instance. This hash table does have a configurable 
timeout value (`hash_table_tout`, defaults to 1 hour), which makes it 
possible to still use it in a way you've described. However, from the 
code it's my understanding that timed out hash table entries are only 
deleted when they're encountered during processing, so it's not entirely 
deterministic that old entries are always deleted after they've timed 
out. The RPC command `rtpengine.get_hash_total` can be used to inspect 
the current size of the hash table.


More information about the sr-users mailing list