[HBASE-6868] Skip checksum is broke; are we double-checksumming by default?

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 0.94.0, 0.94.1
• Fix Version/s: 0.94.2
• Component/s: HFile, wal
• Hadoop Flags: Reviewed
• Assignee: Lars Hofhansl
• Reporter: LiuLei
• Created: 22/Sep/12 03:20
• Updated: 07/Apr/13 05:03
• Resolved: 25/Sep/12 17:39

Description

The HFile contains checksums for decrease the iops, so when Hbase read HFile , that dont't need to read the checksum from meta file of HDFS. But HLog file of Hbase don't contain the checksum, so when HBase read the HLog, that must read checksum from meta file of HDFS. We could add setSkipChecksum per file to hdfs or we could write checksums into WAL if this skip checksum facility is enabled

Issue Links

• blocks: HBASE-6798 HDFS always read checksum form meta file
• blocks: HDFS-3429 DataNode reads checksums even if client does not need them
• is related to: HBASE-5074 support checksums in HBase block cache
• is related to: HBASE-6040 Use block encoding and HBase handled checksum verification in bulk loading using HFileOutputFormat