[LUCENE-6841] LZ4 compression using too much CPU time

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 5.3.1
• Component/s: core/codecs

Environment

Linux, Java 8

• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Karl von Randow
• Created: 16/Oct/15 03:03
• Updated: 28/Aug/22 14:44

Description

I am using Lucene for search indexing, including storing a large number of small fields, and some larger plain text fields, and searching using both exact matches and analyzed queries.

LZ4 (specifically the decompress method) is using nearly exactly 50% of the application's CPU time.

It seems to me that LZ4 is inappropriate for my use case. I note that I can choose BEST_SPEED or BEST_COMPRESSION.

Would it be palatable to add a NO_COMPRESSION option, or some way to pick and choose which fields get compressed? Perhaps a minimum length of a field could be specified before it's compressed? I'm not sure if that's possible.

If this approach, or similar is palatable, I would be happy to contribute a patch (or to consume and test a patch).