[SR-Users] db_cluster together with the registrar module = signal 11

[Øyvind Kolbu]

On 2012-08-30 at 13:32, Daniel-Constantin Mierla wrote:
> Then, have in mind that there are several operations, one after the other:
> - update - which do update to all write db servers
> - test affected rows (which is always working on last write (update) 
> connection)
> - insert if affected rows is 0
> 
> So it is not an atomic operation, like 
> updated_and_if_affected_rows_is_0_then_insert. All this layer is done in 
> usrloc, in sequential steps, working fine for one server, but not for 
> multiple nodes.

After reading this mail and usrloc/ucontact.c I have a much better idea of
how this works, thanks!

> I am not sure what it will take to implement this kind of operation 
> inside the database drivers, then it may work. TBased on quick thoughts, 
> the code is there, just that has to be structured for each db connector 
> and exported via db api and propagated to db_cluster.

This would be great.

> You have to do cross replication at database layer and use db_cluster as 
> read/write for failover access (e.g., try read/write on db1 and if 
> fails, try the other one).

Yes, this is what we'll probably end up with. Thanks for all your answers!

-- 
Øyvind Kolbu