Yep, talking about HDFS replication.
On Mon, May 6, 2013 at 5:55 PM, Otis Gospodnetic <[email protected] > wrote: > Thanks Bryan and Jeremy, good info. > > When you say "replication", you are referring to HDFS block > replication, not HBase cluster/table replication, correct? > > Thanks, > Otis > -- > Search Analytics - http://sematext.com/search-analytics/index.html > HBASE Performance Monitoring - http://sematext.com/spm/index.html > > > > > > On Mon, May 6, 2013 at 5:44 PM, Bryan Beaudreault > <[email protected]> wrote: > > We run multiple HBase clusters of various sizes, each is spread over 4 > AZs. > > Yes, there is a definite write latency added due to replication, and yes > > there is a transfer cost that is not negligible but I can't comment on > the > > specifics of. > > > > Despite that though we use HBase as the primary datastore for multiple > > online APIs and the sink for many hadoop jobs, and are able to keep total > > response times plenty low for our apps. Of course this is very specific > to > > our read/write patterns, etc, so YMMV. > > > > > > > > > > On Mon, May 6, 2013 at 4:59 PM, Jeremy Carroll <[email protected]> > wrote: > > > >> We tried it. It did not work well. According to AWS, cross AZ latency > >> should be ~1ms. In practice we have seen large variances. Also if you > are > >> using larger instances with placement groups, they do not work cross AZ > as > >> well. > >> > >> With this in mind we went the multi-cluster route, and kept all nodes > for a > >> cluster in 1 AZ. > >> > >> > >> On Mon, May 6, 2013 at 10:37 AM, Otis Gospodnetic < > >> [email protected]> wrote: > >> > >> > Hi, > >> > > >> > Do people spread HBase clusters over multiple EC2 Availability Zones, > >> > or is that a big no-no? Cross-AZ communication is supposedly going > >> > over fast fiber optic cables. > >> > > >> > Thanks, > >> > Otis > >> > -- > >> > Search Analytics - http://sematext.com/search-analytics/index.html > >> > HBASE Performance Monitoring - http://sematext.com/spm/index.html > >> > > >> >
