2011/2/22 Jody McIntyre <jodym@xxxxxxxxxxxxxxxx>: > On Mon, Feb 21, 2011 at 10:00 PM, Fujii Masao <masao.fujii@xxxxxxxxx> wrote: >> >> The resource agents for MySQL and DRBD have been implemented as >> master/slave ones. So I think that the resource agent for PostgreSQL also >> should be done the same way, i.e., you should implement only "start" and >> "stop" but also "promote" and "demote". > > The trouble with postgres is there's no easy way to "demote" a master > machine to a slave. You need to create a new master, back up its database, > and restore it onto the slave before starting it. This seems difficult to > implement, and pacemaker is already very complicated as it is. > > We are seriously considering writing our own tool that simply tests the > master from the slave, and runs a very simple shell script to take over if > necessary. > We have some work in progress in repmgr for that. And it offers stronger choice when you have several standby and want to pick the most up to date to become a new master. -- Cédric Villemain 2ndQuadrant http://2ndQuadrant.fr/ ; PostgreSQL : Expertise, Formation et Support -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
