vasiliev vasya <vasyvasilie at yandex.ru> writes:
> We have good working replication scheme with one master and several slave servers, created and worked now no slony1-1* version and planned to migrate on slony1-2* version. Now we have some problems with big changes on master database, and that's why our replicas late from master for considerable time. I started to tune some slony settings, but unfortuanally, i didn't found configuration of slony that's works well in this case (possible, i should tune postgresql with slony, but how?). I'm interested in two ways:
> 1. The configuration when the replication system have max priority and master/slaves servers preffered works firstefull to sync data, not to responce to sql queries from our programs.
> 2. The configuration when responce of queries sould be preffered than replication, replication can late some.
>
> Is it possible to tune slony (any vesion) and postgresql (last version) for theese two ways?

Not really, no.

There's not a mechanism in PostgreSQL to control priority of workload,
so we don't have a particular way to tune things in this fashion.

The amount of time taken between processing SYNCs is a *loose* sort of
control for this (see the -s and -t options to slon) , but more in the
"you can make Slony-I back off somewhat" fashion.  And unfortunately, if
your system's overloaded, that will cease to have much effect pretty
quickly.

I'll bounce this over to the hackers list, as it could be an interesting
idea.  But there's a pretty decent chance of it getting pooh-poohed.
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