Re: Cluster performance with data node down

On Wed, 2007-08-15 at 20:02 +0200, Giulio Ferro wrote:
> What we are talking about here is a query which on a single machine
> configuration (no cluster) takes less than .3 sec. to complete.
>
> So we have
> Time to complete select query :
> *) single machine - no cluster : < 0.3 seconds
> *) cluster - 2/2 data nodes : < 0.4 seconds
> *) cluster - 1/2 data nodes : > 12 seconds.
>
> What we have here is a configuration without any workload (except
> the query I execute). As far as I can tell there is no task here which
> can benefit from parallelization.
>
> But even if it were, parallelization could in no way account for a
> difference in execution of a factor of 30 (12 / 0.4)
>
> As a software architect my guess is that here we have something
> of an anomaly in the way things are managed in a degraded cluster.
>
> I could also add data nodes, but unless some of you explains to me
> how this could really set things right I'm still thinking we are barking
> at the wrong tree...

What queries? on what tables? on what data set? EXPLAIN output?

cluster configuration?

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