The HBase support checksums in HBase block cache in HBASE-5074<https://issues.apache.org/jira/browse/HBASE-5074> jira. The HBase support checksums for decrease the iops of HDFS, so that HDFS dont't need to read the metadata of block file. But in hadoop-0.20.2-cdh3u5 version, BlockSender still read the metadata file even if the hbase.regionserver.checksum.verify property is ture. Because the HBASE-5074 jira can't decrease the iops of HDFS, so I want to set hbase.regionserver.checksum.verify property to fasle. 2012/9/16 Stack <[email protected]>
> On Sat, Sep 15, 2012 at 10:31 AM, jlei liu <[email protected]> wrote: > > I use Hbase0.94.1 and hadoop-0.20.2-cdh3u5. > > > > The Hbase0.94.1 write checksums in HBase block, so we don't need to read > > checksums from metadata file of block file. But I find the BlockSender > > still read checksums from metadata file of block file every time, > > How are you figuring this? That sounds like a regression. > > In 0.94.x the default is that hbase.regionserver.checksum.verify is > true which should have hbase doing checksum verify on read rather than > hdfs. > > > so the > > Hbase0.94.1 can't decrease the iops, that is right? If that is right, > > should I set the hbase.regionserver.checksum.verify property to false in > > order to avoid the Hbase0.94.1 to verify th checksum? > > > > It would be interesting flipping the switch. If things went faster, > then for sure there is a regression. > St.Ack >
