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https://issues.apache.org/jira/browse/CASSANDRA-13291?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16208855#comment-16208855
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Michael Kjellman commented on CASSANDRA-13291:
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Re: the {{newHasher()}} stuff, I agree with you but the reason we got here is
because of the fact that the ultimate goal here (to switch the hashing function
we're using) was split into two tickets to separate all this boring refactoring
from the actual conversation about what hashing function we should use going
forward and make that change pretty small (obviously high impact but small in
number of LoC, assuming we have this boring refactor ticket done). I avoid
wrapping the wrapper because I felt keeping it as basic as possible would make
the number of changes needed to handle rolling upgrades etc would be easier
I just committed all your other comments/findings, squashed, and force pushed
it up to my branch.
> Replace usages of MessageDigest with Guava's Hasher
> ---------------------------------------------------
>
> Key: CASSANDRA-13291
> URL: https://issues.apache.org/jira/browse/CASSANDRA-13291
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Michael Kjellman
> Assignee: Michael Kjellman
> Attachments: CASSANDRA-13291-trunk.diff
>
>
> During my profiling of C* I frequently see lots of aggregate time across
> threads being spent inside the MD5 MessageDigest implementation. Given that
> there are tons of modern alternative hashing functions better than MD5
> available -- both in terms of providing better collision resistance and
> actual computational speed -- I wanted to switch out our usage of MD5 for
> alternatives (like adler128 or murmur3_128) and test for performance
> improvements.
> Unfortunately, I found given the fact we use MessageDigest everywhere --
> switching out the hashing function to something like adler128 or murmur3_128
> (for example) -- which don't ship with the JDK -- wasn't straight forward.
> The goal of this ticket is to propose switching out usages of MessageDigest
> directly in favor of Hasher from Guava. This means going forward we can
> change a single line of code to switch the hashing algorithm being used
> (assuming there is an implementation in Guava).
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