On Tue, Apr 19, 2011 at 4:09 PM, Ted Dunning <[email protected]> wrote: > This is kind of true. > > There is only one regionserver to handle the reads, but there are > multiple copies of the data to handle fail-over. > > On Tue, Apr 19, 2011 at 12:33 PM, Otis Gospodnetic > <[email protected]> wrote: >> 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: >
It is not "kinda of true". It "is" true. A summary of slide 22 is: Cassandra 20 nodes Replication Factor 20 Results in: 20 nodes capable of serving this reads! With HBase, regardless of how many HDFS file copies exist, only one RegionServer can actively serve a region.
