On 5 October 2011 11:40, Guillaume Lelarge <[email protected]> wrote: > On Wed, 2011-10-05 at 12:22 +0200, Guillaume Lelarge wrote: >> On Wed, 2011-10-05 at 10:13 +0100, Thom Brown wrote: >> > On 5 October 2011 10:05, Guillaume Lelarge <[email protected]> wrote: >> > > On Wed, 2011-10-05 at 09:38 +0100, Thom Brown wrote: >> > >[...] >> > >> This seems like it should be a very common setup, so does pgPool have >> > >> provisioning for this, like having a 3rd pgPool to manage them >> > >> somehow? >> > >> >> > > >> > > No, it's not possible right now, and there's no discussion between >> > > developers to do something like this (at least on pgpool-hackers). >> > >> > So no-one has ever configured pgPool to have true HA? Isn't there any >> > kind of black magick trickery one can do with the existing config >> > options to achieve this? >> > >> >> I guess true HA really depends on your context. >> >> Say we have two data centers (DC1 and DC2), two PostgreSQL servers (PG1 >> and PG2), and two pgpool servers (PGP1 and PGP2). I would have all users >> access to the database through PGP1. Say that DC1 isn't available >> anymore, what I would do is change the IPVS so that all users go through >> PGP2, change PGP2 configuration so that it cannot access to PG1, and >> make sure that PG2 is the new master. Which of course is not automatic, >> there are a few steps that need manual work. >> >> But actually, what you are asking for is quite hard to have.
I understand that MySQL cluster suite (or whatever it's called) has a master controller which provides this somehow. >> > So in load balancing mode, is backend_*0 regarded by pgPool to be the >> > primary, or is pgPool clever and polls the servers to figure this out? >> > >> >> You mean, in master_slave mode. AFAIR, yes, it is. But I'll check. >> > > And I was wrong. At least when you first start pgpool. How does it then know where to direct write queries to? Thom _______________________________________________ Pgpool-general mailing list [email protected] http://pgfoundry.org/mailman/listinfo/pgpool-general
