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https://issues.apache.org/jira/browse/CASSANDRA-6127?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13815286#comment-13815286
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Jonathan Ellis commented on CASSANDRA-6127:
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ISTM that FD processing Gossip updates synchronously is a fundamental problem.
Any hiccup in processing will cause FD false positives. (And even if our own
code is perfect, GC pauses can still do this to us.)
Wouldn't it be better if we:
- time heartbeats based on when they arrive instead of when Gossip processes
them
- teach FD to recognize that its information is only good up to the most
recently processed message -- the absence of messages after that doesn't mean
everyone is down unless the Gossip stage is empty
> vnodes don't scale to hundreds of nodes
> ---------------------------------------
>
> Key: CASSANDRA-6127
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6127
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Environment: Any cluster that has vnodes and consists of hundreds of
> physical nodes.
> Reporter: Tupshin Harper
> Assignee: Jonathan Ellis
> Attachments: 6000vnodes.patch, AdjustableGossipPeriod.patch,
> delayEstimatorUntilStatisticallyValid.patch
>
>
> There are a lot of gossip-related issues related to very wide clusters that
> also have vnodes enabled. Let's use this ticket as a master in case there are
> sub-tickets.
> The most obvious symptom I've seen is with 1000 nodes in EC2 with m1.xlarge
> instances. Each node configured with 32 vnodes.
> Without vnodes, cluster spins up fine and is ready to handle requests within
> 30 minutes or less.
> With vnodes, nodes are reporting constant up/down flapping messages with no
> external load on the cluster. After a couple of hours, they were still
> flapping, had very high cpu load, and the cluster never looked like it was
> going to stabilize or be useful for traffic.
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