[OpenSIPS-Users] usrloc restart persistency on seed node

[John Quick]

Hi Alexei,

Many thanks for your reply to my query about syncing the seed node for
usrloc registrations.
I just tried the command you suggested and it does solve the problem. I also
read the other thread you pointed to.

I do not really understand the need for the seed node, especially not for
the case of memory based registrations.
A seed node makes sense if that node has a superior knowledge of the
topology or the data than the other nodes. It's view of the universe is to
be trusted more than the view held by any other node.
However, in the case of a cluster topology that is pre-defined (no
auto-discovery) and for full-sharing of usrloc registration data held
exclusively in memory, then all the nodes are equal - there is no superior
knowledge that can exist in one node. The one with the most accurate view of
the world is the one that has been running the longest.

I am wondering if there is a justifiable case for an option that would
disable the concept of the seed node and make it so that, on startup, every
instance will attempt to get the usrloc data from any other running instance
that has data available. In effect, I can mimic this behaviour by adding the
command line you suggested just after opensips has started:
opensipsctl fifo ul_cluster_sync

Am I missing something here about the concept of the seed node?
It concerns me that this seed concept is at odds with the concept of true
horizontal scalability.
All nodes are equal, but some are more equal than others!

John Quick
Smartvox Limited
Web: www.smartvox.co.uk