On 11/19/13 09:13, Mike James wrote:
> I am using slony1 log-shipping to replicate some data to a remote
> location thru a VPN tunnel. A cron job running every minute applies the
> logs to the remote slave. So the latency is at least one minute. Is
> there a way to more precisely measure the latency between the origin and
> slave?

Log shipping replicas are not known to the origin of a set. There are no
sl_confirm records for them. Only the slon deamon, writing the log
shipping files, knows that it is doing so. That node is by design a
replica itself and even it has no knowledge about who is possibly
consuming those log shipping files. To determine the lag between the
"origin" and a replica you need to know the current time on the origin
and the timestamp of the last SYNC event from that origin replicated to
the replica. Since log shipping replicas have no sl_confirm records,
there is nothing inside the Slony system that could answer that question.


Jan




> 
> Thanks, 
> Mike
> 
> 
> 
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