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Phabricator commented on HBASE-5074: ------------------------------------ dhruba has commented on the revision "[jira] [HBASE-5074] Support checksums in HBase block cache". INLINE COMMENTS src/main/java/org/apache/hadoop/hbase/io/hfile/HFileBlock.java:257 In my opinion, we do not need a majorVersion in the in-memory HFileBlock object. Adding it will add to heap-space (albeit not much), but we can always add it later when needed... especially because it is only in-memory and not a disk-format change. Ted: do you agree? REVISION DETAIL https://reviews.facebook.net/D1521 > support checksums in HBase block cache > -------------------------------------- > > Key: HBASE-5074 > URL: https://issues.apache.org/jira/browse/HBASE-5074 > Project: HBase > Issue Type: Improvement > Components: regionserver > Reporter: dhruba borthakur > Assignee: dhruba borthakur > Attachments: D1521.1.patch, D1521.1.patch, D1521.10.patch, > D1521.10.patch, D1521.10.patch, D1521.10.patch, D1521.10.patch, > D1521.2.patch, D1521.2.patch, D1521.3.patch, D1521.3.patch, D1521.4.patch, > D1521.4.patch, D1521.5.patch, D1521.5.patch, D1521.6.patch, D1521.6.patch, > D1521.7.patch, D1521.7.patch, D1521.8.patch, D1521.8.patch, D1521.9.patch, > D1521.9.patch > > > The current implementation of HDFS stores the data in one block file and the > metadata(checksum) in another block file. This means that every read into the > HBase block cache actually consumes two disk iops, one to the datafile and > one to the checksum file. This is a major problem for scaling HBase, because > HBase is usually bottlenecked on the number of random disk iops that the > storage-hardware offers. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira