On Wed, Oct 13, 2010 at 3:31 PM, Stack <[email protected]> wrote: > On Tue, Oct 12, 2010 at 11:06 PM, Abhijit Pol <[email protected]> wrote: > > we did swapoff -a and then updated fstab to permanently turn it off. > > You might not want to turn it off completely. One of the lads was > recently talking about the horrors that can happen when no swap. >
What is the horror? > > But sounds like you were doing over eager swapping up to this? > > > we observed swap was actually happening on RSs and after we turned it off > we > > have much stable RSs. > > > > i can tell what we have, not sure that is optimal, in fact looking for > > comments/suggestions from folks who have used it more: > > 64GB RAM ==> 85% given to HBASE HEAP (30% memstore, 60%block cache) , > 512MB > > DN and 512MB TT > > > > So, I'm bad at math, but thats a heap of 50+GB? Hows that working out > for you? You played with GC tuning at all? You might give more to > the DN and the TT since you have plenty -- and more to the OS... > perhaps less to hbase? > > How many disks? > > > we have 64KB HDFS block size > > Do you mean 64MB? > > > and 8K Hbase block size as our load is random > > read dominated. > > > > Small cells? If so, 8k can help some over having the 64k default. > > You've done the other stuff -- ulimits and xceivers? > > Hows it running for you? > > St.Ack >
