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Subject: Re: How to warm up a cold node
From: =?ISO-8859-1?Q?H=E9ctor?= Izquierdo Seliva <izquierdo@strands.com>
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Date: Tue, 19 Apr 2011 14:41:20 +0200
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Shouldn't the dynamic snitch take into account response times and ask a
slow node for less requests? It seems that at node startup, only a
handfull of requests arrive to the node and it keeps up well, but
there's moment where there's more than it can handle with a cold cache
and starts droping messages like crazy.

Could it be the transition from slow node to ok node is to steep?


El vie, 15-04-2011 a las 16:19 +0200, Peter Schuller escribió:
> > Hi everyone, is there any recommended procedure to warm up a node before
> > bringing it up?
> 
> Currently the only out-of-the-box support for warming up caches is
> that implied by the key cache and row cache, which will pre-heat on
> start-up. Indexes will be indirectly preheated by index sampling, to
> the extent that they operating system retains them in page cache.
> 
> If you're wanting to pre-heat sstables there's currently no way to do
> that (but it's a useful feature to have). Pragmatically, you can
> script something that e.g. does "cat path/to/keyspace/* > /dev/null"
> or similar. But that only works if the total database size fits
> reasonably well in page cache.
> 
> Pre-heating sstables on a per-cf basis on start-up would be a nice
> feature to have.
>