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From Héctor Izquierdo Seliva <>
Subject Re: Disable Swap? batch_mutate failed: out of sequence response
Date Wed, 06 Apr 2011 10:24:07 GMT
El mié, 06-04-2011 a las 09:18 +0200, Héctor Izquierdo Seliva escribió:
> I took a look at vmstats, and there was no swap. Also, our monitoring
> tools showed no swap being used at all. It's running with mlockall and
> all that. 8GB heap on a 16GB machine

I tried disabling swap completely, and the problem is still appearing.

> El mar, 05-04-2011 a las 21:24 +0200, Peter Schuller escribió:
> > > Would you recommend to disable system swap as a rule?   I'm running on Debian
64bit and am seeing light swapping:
> > 
> > I'm not Jonathan, but *yes*. I would go so far as to say that
> > disabling swap is a good rule of thumb for *most* production systems
> > that serve latency sensitive traffic. For a machine dedicated to
> > Cassandra, you definitely want to disable swap.
> > 
> > There's just nothing to be gained really, but lots to loose. There is
> > nothing that you *want* swapped out. All the memory you use needs to
> > be in memory. You don't want the heap swapped out, you don't want the
> > off-heap jvm malloc stuff swapped out, you don't want stacks swapped
> > out,etc. As soon as you start swapping you very quickly run into poor
> > and unreliable performance. Particularly during GC.
> > 

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