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. > > > >
