I don't know why you would want to serve from other region servers if all they did was transferring data, the current situation would be better.
J-D On Tue, Apr 19, 2011 at 2:26 PM, Otis Gospodnetic <[email protected]> wrote: > Thanks J-D! > > Yeah, what you describe below is also something that I think Edward pointed > out > in some of his slides - that you could route all requests for X to the place > where X is when you don't want to have X cached (in app-level caches and/or > OS-level caches) on multiple servers, but that sometimes you do want to > "waste" > memory like this because you have to spread requests for X over more servers. > > Are these two modes going to be supported in HBase? > > Thanks, > Otis > ---- > We're hiring HBase hackers for Data Mining and Analytics > http://blog.sematext.com/2011/04/18/hiring-data-mining-analytics-machine-learning-hackers/ > > > > > > ----- Original Message ---- >> From: Jean-Daniel Cryans <[email protected]> >> To: [email protected] >> Sent: Tue, April 19, 2011 5:10:07 PM >> Subject: Re: Region replication? >> >> We have something on the menu: >> https://issues.apache.org/jira/browse/HBASE-2357 Coprocessors: Add >> read-only region replicas (slaves) for availability and fast region >> recovery >> >> Something to keep in mind is that you have to cache the data for each >> replica, so a row could be in 3 different caches (which also have to >> be warmed). I guess this is useful for very hot rows compared to a >> much larger read distribution, in which case you'd really want to >> cache it only once else you'd need 3x the memory to hold your dataset >> in cache. >> >> J-D >> >> On Tue, Apr 19, 2011 at 12:33 PM, Otis Gospodnetic >> <[email protected]> wrote: >> > Hi, >> > >> > I imagine lots of HBase folks have read or will want to read >> > http://blog.milford.io/2011/04/why-i-am-very-excited-about-datastaxs-brisk/ > , >> > including comments. >> > >> > My question has to do with one of the good comments from Edward Capriolo, >>who >> > pointed out that some of the Configurations he described in his Cassandra >> as >> > Memcached talk ( >> > http://www.edwardcapriolo.com/roller/edwardcapriolo/resource/memcache.odp ) >>are >> > not possible with HBase because in HBase there is only 1 copy of any given >> > Region and it lives on a single RegionServer (I'm assuming this is >>correct?), >> > thus making it impossible to spread reads of data from one Region over >>multiple >> > RegionServers: >> > >> > >>http://blog.milford.io/2011/04/why-i-am-very-excited-about-datastaxs-brisk/#comment-187253604 >> >> > >> > >> > So I poked around on search-hadoop.com and JIRA, and looked at >> > http://hbase.apache.org/book/regions.arch.html to see about this > limitation, >> > whether it's even mentioned as a limitation, whether there are plans to >>change >> > it or if there are some configuration alternatives that would make some of >>those >> > configurations described by Ed possible with HBase, but I actually didn't >>find >> > any explicit information about that. >> > >> > Would anyone care to comment? :) >> > >> > Many thanks, >> > Otis >> > -- >> > We're hiring HBase hackers for Data Mining and Analytics >> > >>http://blog.sematext.com/2011/04/18/hiring-data-mining-analytics-machine-learning-hackers/ >> >> > >> >
