Den 13/03/2013 kl. 18.13 skrev Jeff Janes <jeff.ja...@gmail.com>: > On Wed, Mar 13, 2013 at 8:24 AM, Niels Kristian Schjødt > <nielskrist...@autouncle.com> wrote: > I'm considering the following setup: > > - Master server with battery back raid controller with 4 SAS disks in a RAID > 0 - so NO mirroring here, due to max performance requirements. > - Slave server setup with streaming replication on 4 HDD's in RAID 10. The > setup will be done with synchronous_commit=off and synchronous_standby_names > = '' > > Out of curiosity, in the presence of BB controller, is synchronous_commit=off > getting you additional performance?
Time will show :-) > > > So as you might have noticed, clearly there is a risk of data loss, which is > acceptable, since our data is not very crucial. However, I have quite a hard > time figuring out, if there is a risk of total data corruption across both > server in this setup? E.g. something goes wrong on the master and the wal > files gets corrupt. Will the slave then apply the wal files INCLUDING the > corruption (e.g. an unfinished transaction etc.), or will it automatically > stop restoring at the point just BEFORE the corruption, so my only loss is > data AFTER the corruption? > > It depends on where the corruption happens. WAL is checksummed, so the slave > will detect a mismatch and stop applying records. However, if the corruption > happens in RAM before the checksum is taken, the checksum will match and it > will attempt to apply the records. > > Cheers, > > Jeff
