cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Michael Kjellman (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-13291) Replace usages of MessageDigest with Guava's Hasher
Date Tue, 17 Oct 2017 16:12:00 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-13291?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16207853#comment-16207853
] 

Michael Kjellman commented on CASSANDRA-13291:
----------------------------------------------

[~beobal] yeah, originally i left the code path for RR the same for exactly the reasons you
mentioned... after Jason did his microbenchmarking though and then pointed it out I changed
it over... I'm not sure I see how the latest change is double hashing though... I'm happy
to just revert back to what I had and add a comment re: the ThreadLocal to the effect of "not
wanting to break is as it works right now and it will always be md5 anyways so it's not like
it hurts any functionality around moving to Guava etc.." lmk.

> 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).



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscribe@cassandra.apache.org
For additional commands, e-mail: commits-help@cassandra.apache.org


Mime
View raw message