[Pgpool-general] Why need set 'slony' submode in pgpool.conf

[Guillaume Lelarge]

Le 12/01/2011 09:40, Zhidong She a écrit :
> Hi Guys,
> 
> I'm just a little confused about master_slave_sub_mode option in
> configuration file.
> If we build a master/slave db replication and deploy pgpool on top of
> them, we need set master_slave_mode to true. It does make sence.
> But why does PgPool need to set "slony" sub mode? What's the purpose
> of this option for pgpool?
> I think if we use master/slave mode in pgpool, it's the DB's
> responsibility to build a master/slave replication using slony or log
> streaming. Pgpool doesn't care about how the data is replicated
> between master and slave.
> 

I didn't check in the code (don't have the time right now), but I guess
it's needed for pgpool to know if it needs to use some advanced
features, like getting the lag between a master and a slave to "disable"
a node with too much lag. Which, IIUI, is only available in streaming mode.


-- 
Guillaume
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