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https://issues.apache.org/jira/browse/CASSANDRA-8614?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14277139#comment-14277139
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Aleksey Yeschenko commented on CASSANDRA-8614:
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3.0 will not require JDK8, but 3.1 will probably should. As things stand right
now, the checksum algo depends strictly on the version in the descriptor, and
those are static.
We could probably encode the algo used in metadata, easily, so the current
scheme is not a big deal of a limitation in itself, but I'd slightly prefer
switching in 3.1, unconditionally.
> Select optimal CRC32 implementation at runtime
> ----------------------------------------------
>
> Key: CASSANDRA-8614
> URL: https://issues.apache.org/jira/browse/CASSANDRA-8614
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Ariel Weisberg
> Labels: performance
> Attachments: 8614.patch
>
>
> JDK 8 has support for an intrinsic for CRC32 that runs at 12-13 gigabytes/sec
> per core in my quick and dirty test. PureJavaCRC32 is < 800 megabytes/sec if
> I recall and it has a lookup table that evicts random cache lines every time
> it runs.
> In order to capture the benefit of that when it is available we can select a
> CRC32 implementation at startup in a static block.
> If JDK 8 is not what is running we can fall back to the existing
> PureJavaCRC32 implementation.
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