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https://issues.apache.org/jira/browse/CASSANDRA-617?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12788466#action_12788466
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Jaakko Laine commented on CASSANDRA-617:
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> Wouldn't it be worth making gossip state names an enum? This would (a) make
> it harder to screw things up with name collisions, and (b) make name part of
> gossip load almost negligible.
Yeah, I was also thinking about making the names shorter (or enum), but this is
only part of the problem. Since we have four different move states, we also
have the token in the gossiper four times (three of which are obsolete at any
time). Biggest impact in reducing total amount of data in the gossiper would be
to reduce the amount of move states to one, but this discussion has not yet
reached a conclusion (#572).
> Compress the messages which are being sent. I have seen 5:1 compression is
> achievable. So if you send 117 per the JIRA this is automatically 500+.
Compression sounds good, but needs to be investigated how much it would
actually help in this case. Gossip digest is IP:generation:version, so it
should compress quite well. Big part of ApplicationState payload is random data
(token), however, so it will not compress so well. Squeezing many digests into
one Syn message might not help as much as it seems on paper, as Ack might not
be able to keep up the pace (even now it starts to drop data sooner than Syn).
Now of course during normal operation Ack mainly carries gossip digests and
"empty" EPStates (only heartbeat), so APState compress ratio might not be a
problem at all.
> move to TCP and compress and send all digests.
Wouldn't like to do this lightly, but let's keep it in mind. It would need
rather big cluster before TCP overhead is worth paying for.
> if we can get to ~500 with compression and the simpler fixes
Yeah, I agree there is no need to rush, so let's do the simple stuff now and
see when/if we need more complex stuff later.
> gossiper scalability
> --------------------
>
> Key: CASSANDRA-617
> URL: https://issues.apache.org/jira/browse/CASSANDRA-617
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Affects Versions: 0.5
> Reporter: Jaakko Laine
> Fix For: 0.5
>
> Attachments: averages.png, spread_100.png, spread_50.png,
> spread_90.png
>
>
> Improve gossiper scalability.
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