[HBASE-11927] Use Native Hadoop Library for HFile checksum (And flip default from CRC32 to CRC32C)

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.2.0, 2.0.0
• Component/s: Performance
• Hadoop Flags: Reviewed

Release Note

Checksumming is cpu intensive. HBase computes additional checksums for HFiles (hdfs does checksums too) and stores them inline with file data. During reading, these checksums are verified to ensure data is not corrupted. This patch tries to use Hadoop Native Library for checksum computation, if it’s available, otherwise falls back to standard Java libraries. Instructions to load NHL in HBase can be found here (http://hbase.apache.org/book.html#hadoop.native.lib).

Default checksum algorithm has been changed from CRC32 to CRC32C primarily because of two reasons: 1) CRC32C has better error detection properties, and 2) New Intel processors have a dedicated instruction for crc32c computation (SSE4.2 instruction set)*. This change is fully backward compatible. Also, users should not see any differences except decrease in cpu usage. To keep old settings, set configuration ‘hbase.hstore.checksum.algorithm’ to ‘CRC32’.

* On linux, run 'cat /proc/cpuinfo’ and look for sse4_2 in list of flags to see if your processor supports SSE4.2.

• Assignee: Apekshit Sharma
• Reporter: Michael Stack
• Created: 09/Sep/14 23:35
• Updated: 16/Jun/22 05:59
• Resolved: 23/Feb/16 07:22

Description

Up in hadoop they have this change. Let me publish some graphs to show that it makes a difference (CRC is a massive amount of our CPU usage in my profiling of an upload because of compacting, flushing, etc.). We should also make use of native CRCings – especially the 2.6 HDFS-6865 and ilk – in hbase but that is another issue for now.

Issue Links

• is duplicated by: HBASE-8323 Low hanging checksum improvements
• is related to: HADOOP-11980 Make DataChecksum APIs public
• relates to: HBASE-14738 Backport HBASE-11927 (Use Native Hadoop Library for HFile checksum) to 0.98

Sub-Tasks

• More doc around native lib setup and check and crc: Resolved