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https://issues.apache.org/jira/browse/CASSANDRA-2536?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13026710#comment-13026710
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Tyler Hobbs commented on CASSANDRA-2536:
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{quote}
Wouldn't that update be DOA then? I thought we checked to make sure the new
migration compared after the current migration (as well as making sure the new
migration's previous version matches with the current version).
{quote}
We do check that the previous version matches, but the migration is applied
locally without comparing the current and new uuids.
{quote}
If the clocks are that far off sync, I think the cluster has bigger problems
(like writes not being applied).
{quote}
This can theoretically happen with clocks being off by only tens of
milliseconds.
{quote}
And unlike with data modification, I can't think of a use for doing "clever"
things w/ a client side timesamp. So pushing it to the client doesn't really
solve anything, just means you need to sync clocks across more machines.
{quote}
Not for clever purposes -- it seems to me that clients making schema
modifications are more likely to be centralized, so schema changes coming from
a single client will (almost) always have increasing timestamps.
> Schema disagreements when using connections to multiple hosts
> -------------------------------------------------------------
>
> Key: CASSANDRA-2536
> URL: https://issues.apache.org/jira/browse/CASSANDRA-2536
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Affects Versions: 0.8 beta 1
> Environment: Two node 0.8-beta1 cluster with one seed and JNA.
> Reporter: Tyler Hobbs
> Assignee: Tyler Hobbs
> Attachments: schema_disagree.py
>
>
> If you have two thrift connections open to different nodes and you create a
> KS using the first, then a CF in that KS using the second, you wind up with a
> schema disagreement even if you wait/sleep after creating the KS.
> The attached script reproduces the issue using pycassa (1.0.6 should work
> fine, although it has the 0.7 thrift-gen code). It's also reproducible by
> hand with two cassandra-cli sessions.
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