On 18 February 2016 at 20:35, Michael Paquier <michael.paqu...@gmail.com> wrote:
> On Thu, Feb 18, 2016 at 5:35 PM, Amit Langote > <langote_amit...@lab.ntt.co.jp> wrote: > > On 2016/02/18 16:38, Craig Ringer wrote: > >> I should resurrect Abhijit's patch to allow the isolationtester to talk > to > >> multiple servers. We'll want that when we're doing tests like "assert > that > >> this change isn't visible on the replica before it becomes visible on > the > >> master". (Well, except we violate that one with our funky > >> synchronous_commit implementation...) > > > > How much does (or does not) that overlap with the recovery test suite > work > > undertaken by Michael et al? I saw some talk of testing for patches in > > works on the N synchronous standbys thread. > > This sounds like poll_query_until in PostgresNode.pm (already on HEAD) > where the query used is something on pg_stat_replication for a given > LSN to see if a standby has reached a given replay position. > No, it's quite different, though that's something handy to have that I've emulated in the isolationtester using a plpgsql function. The isolationtester changes in question allow isolationtester specs to run different blocks against different hosts/ports/DBs. That lets you make assertions about replication behaviour. It was built for BDR and I think we'll need something along those lines in core if/when any kind of logical replication facilities land, for things like testing failover slots, etc. The patch is at: http://git.postgresql.org/gitweb/?p=2ndquadrant_bdr.git;a=commit;h=d859de3b13d39d4eddd91f3e6f316a48d31ee0fe and might be something it's worth having in core as we expand testing of replication, failover, etc. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
