[
https://issues.apache.org/jira/browse/CASSANDRA-12937?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17709226#comment-17709226
]
Claude Warren commented on CASSANDRA-12937:
-------------------------------------------
Looking at CompressionParams there are a number of default configurations e.g.
snappy(), lz4(), and noCompression() that I thought would be in common use.
What I wanted to do was to provide an easy way to get to call those methods as
well as provide the ability to load any compressor via the map.
Also, early on the idea of putting chunk_length_in_kb was rejected with the
"16KiB" form for the input requested.
If it is agreed to remove the shortcuts and use the simple map form with the
parameters I'll make those changes.
I did come across a note that says that configuration file and CQL use
different parameters for compression, thus I onluy implemented
min_compress_ratio and used it to calculate max_compression_length.
So I got to where the code is by trying to support the defaults in
CompressonParams and following the min_compress_ratio not
max_compression_length in the config files.
> Default setting (yaml) for SSTable compression
> ----------------------------------------------
>
> Key: CASSANDRA-12937
> URL: https://issues.apache.org/jira/browse/CASSANDRA-12937
> Project: Cassandra
> Issue Type: Improvement
> Components: Local/Config
> Reporter: Michael Semb Wever
> Assignee: Claude Warren
> Priority: Low
> Labels: AdventCalendar2021, lhf
> Fix For: 5.x
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> In many situations the choice of compression for sstables is more relevant to
> the disks attached than to the schema and data.
> This issue is to add to cassandra.yaml a default value for sstable
> compression that new tables will inherit (instead of the defaults found in
> {{CompressionParams.DEFAULT}}.
> Examples where this can be relevant are filesystems that do on-the-fly
> compression (btrfs, zfs) or specific disk configurations or even specific C*
> versions (see CASSANDRA-10995 ).
> +Additional information for newcomers+
> Some new fields need to be added to {{cassandra.yaml}} to allow specifying
> the field required for defining the default compression parameters. In
> {{DatabaseDescriptor}} a new {{CompressionParams}} field should be added for
> the default compression. This field should be initialized in
> {{DatabaseDescriptor.applySimpleConfig()}}. At the different places where
> {{CompressionParams.DEFAULT}} was used the code should call
> {{DatabaseDescriptor#getDefaultCompressionParams}} that should return some
> copy of configured {{CompressionParams}}.
> Some unit test using {{OverrideConfigurationLoader}} should be used to test
> that the table schema use the new default when a new table is created (see
> CreateTest for some example).
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org
For additional commands, e-mail: commits-h...@cassandra.apache.org
