[HADOOP-12794] Support additional compression levels for GzipCodec

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.2
• Fix Version/s: 2.8.0, 2.7.3, 3.0.0-alpha1
• Component/s: io
• Hadoop Flags: Reviewed
• Release Note: Added New compression levels for GzipCodec that can be set in zlib.compress.level
• Assignee: Ravi Mutyala
• Reporter: Ravi Mutyala
• Created: 11/Feb/16 07:18
• Updated: 30/Aug/16 01:18
• Resolved: 19/Feb/16 22:26

Description

gzip supports compression levels 1-9. Compression level 4 seems to give best compression per CPU time in some of our tests. Right now ZlibCompressor that is used by GzipCodec only supports levels 1,9 and six (default).

Adding all the compression levels that are supported by native ZlibCompressor
can provide more options to tweak compression levels.