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From rohit bhatia <rohit2...@gmail.com>
Subject Re: Cassandra Counters
Date Tue, 25 Sep 2012 13:38:57 GMT
@Sylvain

In a relatively untroubled cluster, even timed out writes go through,
provided no messages are dropped. Which you can monitor on cassandra
nodes. We have 100% consistency on our production servers as we don't
see messages being dropped on our servers.
Though as you mention, there would be no way to "repair" your dropped messages .

On Tue, Sep 25, 2012 at 6:57 PM, Sylvain Lebresne <sylvain@datastax.com> wrote:
>> So general question, should I rely on Counters if I want 100% accuracy?
>
>
> No.
>
>  Even not considering potential bugs, counters being not idempotent, if you
> get a TimeoutException during a write (which can happen even in relatively
> normal conditions), you won't know if the increment went in or not (and you
> have no way to know unless you have an external way to check the value).
> This is probably fine if you use counters for say real-time analytics, but
> not if you use 100% accuracy.
>
> --
> Sylvain

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