Marcelo Michalek wrote:

>Hi! if I use Slony to replicate a Master/Slave config.
>1) When the slave down and back it?s the slave automatic syncrhonized?
>  
>
Yes, when the slon assigned to that node can one again access both
databases, it will bring the subscriber up to date, no problem.

>2) If the Master go dow, The Slave assumes as Master (automatic o
>forced by me?) and when back it is synchronized?
>  
>
No, that is definitely NOT how things work.

If the origin node is taken down, and you want to promote some other
node to take over, you would have to submit a FAILOVER request (see docs
here... <http://linuxfinances.info/info/failover.html>).

At that point, the former origin is discarded, and could not be brought
back without initializing it as a fresh node and subscribing it to the
replication set(s).

The fact that it requires discarding and reinitializing the failed node
makes FAILOVER a pretty undesirable operation.