On Thu, Jun 5, 2014 at 12:55 PM, Francisco Olarte <fola...@peoplecall.com> wrote:
> Hi Sébastien: > > On Thu, Jun 5, 2014 at 5:41 PM, Sébastien Lorion > <s...@thestrangefactory.com> wrote: > > > .... Correct me if I am wrong, but will it not also suffer the same > > limitation as any statement based replication, namely that the "merged" > > slave will have to sustain the same write load as all shards combined ? > > I cannot tell you the exact mimeo behaviour, but if you incremental > replication using an id/timestamp by >pulling< changes from the > masters, you will normally batch them and insert all the changes to > the slaves in a single transaction, which leads to less load as many > times your limit is in transaction rate, not record rate. (i.e., every > 5 minutes you query for all the tuples changed, and insert/update them > all in one go ) ( Also, if tuples are updated many times between > sweeps the slave will get only one ) > > Francisco Olarte. > You are right, requesting changes at fixed time intervals would certainly help reduce the load. I will have to test and see if a good balance can be achieved between not having stale data for too long and keeping up with writes. Sébastien
