|Description||Sets default compression levels for segments and minisegments|
Compress (fast) in digest pipeline or (highly) later. For fast, compress using LZ4 in the digest pipeline. This is what all versions up to 1.5.x did. High: compress using LZ4 in the digest pipeline, then re-compress using Zstd when merging mini-segments into proper segments later. For extreme, compress using Zstd in the digest pipeline, then re-compress using Zstd when merging mini-segments into proper segments later. Extreme is not recommended as the extra compression is not worth the extra CPU time spent.
COMPRESSION_TYPE=high COMPRESSION_LEVEL=9 COMPRESSION_LEVEL_MINI=0 #VALUE_DEDUP_LEVEL=COMPRESSION_LEVEL
Recommended setting depends on the hardware and use case. The rule of
thumb is that high provides a two-times compression ratio over fast at the
cost of using more CPU time for decompressing while searching. Set high as
the default for fresh installs, and keep fast on existing systems to allow
rolling back to 1.5.x. See also