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Re: How does cassandra achieve Linearizability?


Hi Kant,

Clock synchronization is important - you should ensure that ntpd is properly configured on all nodes. If your particular use case is especially sensitive to out-of-order mutations it is possible to set timestamps on the client side using the drivers. https://docs.datastax.com/en/developer/java-driver/3.1/manual/query_timestamps/

We use our own NTP cluster to reduce clock drift as much as possible, but public NTP servers are good enough for most uses. https://www.instaclustr.com/blog/2015/11/05/apache-cassandra-synchronization/

Cheers,
Justin

On Thu, 9 Feb 2017 at 16:09 Kant Kodali <kant@xxxxxxxxxxxx> wrote:
How does Cassandra achieve Linearizability with “Last write wins” (conflict resolution methods based on time-of-day clocks) ?

Relying on synchronized clocks are almost certainly non-linearizable, because clock timestamps cannot be guaranteed to be consistent with actual event ordering due to clock skew. isn't it?

Thanks!
--

Justin Cameron

Senior Software Engineer | Instaclustr




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