I think you meant HBASE-1295 is broader? HBASE-2357 sounds like MySQL replication, and I'm guessing is a bit easier to implement than HBASE-1295. Also in terms of the HBase use cases I think it'd allow more 'online' production installations that are read heavy?
> 3) Highest availability with lowest latency over other concerns with read > replicas updated best effort from the write path This one sounds like it's the simplest to implement and would cover the most common use case (eg, scaling reads)? On Mon, Apr 18, 2011 at 5:10 PM, Andrew Purtell <[email protected]> wrote: >> From: Jason Rutherglen <[email protected]> > >> Andrew, thanks for the information. On the surface it looks like >> HBASE-2357 would be using the same mechanism for streaming the WAL >> (except the master slave failover) as HBASE-1295, however HBASE-2357 >> seems to imply that's not the case? > > It could be done that way, but 2357 has a broader focus right? -- not > master-slave only (though that certainly is an option) but also master-master > maintaining the same write/read ordering as achievable with > single-region-location deployment. Not that such ordering is necessarily > required, but the notion is to consider a three way trade off: > > 1) Strong consistency over other concerns with single region location > deployment > > 2) Higher availability with consistency over write latency with read > replicas and a ZAB- or Paxos-serialized write path > > 3) Highest availability with lowest latency over other concerns with read > replicas updated best effort from the write path > > - Andy > >
