Hi.Small question, little bit off topic. How can i change the default 100GB datanode size to be something else ?
Best Regards. On Thu, Oct 16, 2008 at 10:41 PM, stack <[EMAIL PROTECTED]> wrote: > Daniel Ploeg wrote: > >> Hi all, >> >> I performed a cluster rebalance on my test cluster yesterday (5 >> regionserver >> / datanodes each with approx 400GB - total approx 2TB HDFS) and I would >> like >> to know if the mailing lists have seen similar results to what I've seen. >> >> > > I talked to the lads running hbase here at powerset. They believe they > have seen something similar when they grow the cluster by some significant > percentage (20-30%). The addition of new machines brings on a rebalancing > and thereafter hbase runs "faster". > > I had a single table with a single column family and loaded it up so that >> it >> just about filled the entire cluster. Actually one or two of the nodes had >> run out of space, yet the fifth machine only had 50% of its disks utilised >> (which is why I though a rebalance was in order). There are a total of >> 1475 >> regions in the cluster. Prior to starting the rebalance the cluster only >> had >> about 250GB left to it's disposal. After the rebalance I now have almost >> 800GB free. >> >> > > If 1475 regions, update to 0.18.1 (coming soon). > > Furthermore, I was performing read tests prior to the rebalance and >> getting >> a response time of approx 500ms per row (each row has 10000 column >> instances >> of the column family which were deserialised as part of the test). After >> the >> rebalance my read times reduced to around 340ms. >> >> >> > If you could have fewer columns in a family column, you'll get a bit better > performance: HBASE-867. > > Good on you Daniel, > St.Ack >
