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https://issues.apache.org/jira/browse/CASSANDRA-6127?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13804545#comment-13804545
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Brandon Williams commented on CASSANDRA-6127:
---------------------------------------------

It would be helpful to dump the interval times for a node that is flapping 
(dumpInterArrivalTimes on the FD) so we can see how long the heartbeats are 
taking.  If some are excessively long, we need to get threads dumps/debugger 
timings from the gossiper to see if something is blocking it or taking a long 
time before changing any fundamentals (gossip interval, FD formula) that we 
already know work in principle without vnodes.  Increasing the payload size to 
>32k shouldn't cause these problems, since that is only sent during initial 
state synchronization and isn't all that large to begin with.

> 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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