On Thu, Feb 18, 2016 at 5:35 PM, Amit Langote <Langote_Amit_f8@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.