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https://issues.apache.org/jira/browse/CASSANDRA-2434?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13094864#comment-13094864
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Nick Bailey commented on CASSANDRA-2434:
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Well, I imagine the 'force' option would pick the nearest live node. By 'force'
I mean the option should be posed to the user as "We can't guarantee
consistency in your cluster after this bootstrap since a node is down, if you
would like to do this anyway, specify option X". Just saying you can either
bootstrap or bootstrap from the closest node doesn't convey the implications as
well I don't think.
Maybe we are on the same page and arguing over wording though.
> node bootstrapping can violate consistency
> ------------------------------------------
>
> Key: CASSANDRA-2434
> URL: https://issues.apache.org/jira/browse/CASSANDRA-2434
> Project: Cassandra
> Issue Type: Bug
> Reporter: Peter Schuller
> Assignee: paul cannon
> Fix For: 1.1
>
> Attachments: 2434.patch.txt
>
>
> My reading (a while ago) of the code indicates that there is no logic
> involved during bootstrapping that avoids consistency level violations. If I
> recall correctly it just grabs neighbors that are currently up.
> There are at least two issues I have with this behavior:
> * If I have a cluster where I have applications relying on QUORUM with RF=3,
> and bootstrapping complete based on only one node, I have just violated the
> supposedly guaranteed consistency semantics of the cluster.
> * Nodes can flap up and down at any time, so even if a human takes care to
> look at which nodes are up and things about it carefully before
> bootstrapping, there's no guarantee.
> A complication is that not only does it depend on use-case where this is an
> issue (if all you ever do you do at CL.ONE, it's fine); even in a cluster
> which is otherwise used for QUORUM operations you may wish to accept
> less-than-quorum nodes during bootstrap in various emergency situations.
> A potential easy fix is to have bootstrap take an argument which is the
> number of hosts to bootstrap from, or to assume QUORUM if none is given.
> (A related concern is bootstrapping across data centers. You may *want* to
> bootstrap to a local node and then do a repair to avoid sending loads of data
> across DC:s while still achieving consistency. Or even if you don't care
> about the consistency issues, I don't think there is currently a way to
> bootstrap from local nodes only.)
> Thoughts?
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