REGISTRAR location replication (pua_reginfo) - sr-users

3 Nov 2014

Good morning.

We've got a problem with location memory and database replication 
between "n" kamailios as REGISTRAR servers.

1.- WHAT WE WANNA DO:

- To have "n" Kamailios with their DB and memory "user location" 
replicated.
- Each Kamailio owns its own DB.(It could be also with a common DB).
- Each kamailio has a PUA_REGINFO, PRESENCE, and REGISTRAR roles.
- USRLOC Module with db_mode = 2 (Write-Back scheme).

2.- WHAT WE DON'T WANNA DO:

- USRLOC Module with db_mode != 2 (Write-Back scheme).

3.- BACKGROUND:

- RFC3265
- RFC3680
- RFC3903
- I attach a small architecture graph.

4.- PROBLEMS:

4.1 Deadlock:

Each REGISTER involves a NOTIFY to the other side.
Each NOTIFY involves another NOTIFY to the other side.

There should be a mechanism to avoid PUBLISH reginfo_handle_notify() 
function calls but to PUBLISH save() calls on pua_reginfo module.

Any idea would be appreciated (also to workaround our problem).

4.2 PUA_REGINFO module notify.c

Just FYI.

We think It doesn't comply to RFC3680. It should observe "unkown-param" 
object to aid "Contact" header params such as "Path",
"Received", 
"User_agent" and so on.

We've changed code but for a fast startup we've also avoided 
"unkown-param" and now we're able to see replicated "Path",
"Received 
... params on each DB.

Thanks and best regards.

Eduardo Lejarreta.