"You can trigger minor compaction on an individual SStable file when the percentage of tombstones in that Sstable crosses a user-defined threshold."
We have just one cf with TTL. I don't think the problem comes from there. "Peaks may be occurring during compaction, when Sstable files are memmapped." Ok, but why am I always running between 4 and 6 GB heap used, even when there is no traffic ? 2013/3/13 Alain RODRIGUEZ <arodr...@gmail.com> > "called index_interval set to 128" > > I think this is for BloomFilters actually. > > > 2013/3/13 Hiller, Dean <dean.hil...@nrel.gov> > > Going to 1.2.2 helped us quite a bit as well as turning on LCS from STCS >> which gave us smaller bloomfilters. >> >> As far as key cache. There is an entry in cassandra.yaml called >> index_interval set to 128. I am not sure if that is related to key_cache. >> I think it is. By turning that to 512 or maybe even 1024, you will >> consume less ram there as well though I ran this test in QA and my key >> cache size stayed the same so I am really not sure(I am actually checking >> out cassandra code now to dig a little deeper into this property. >> >> Dean >> >> From: Alain RODRIGUEZ <arodr...@gmail.com<mailto:arodr...@gmail.com>> >> Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" < >> user@cassandra.apache.org<mailto:user@cassandra.apache.org>> >> Date: Wednesday, March 13, 2013 10:11 AM >> To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" < >> user@cassandra.apache.org<mailto:user@cassandra.apache.org>> >> Subject: About the heap >> >> Hi, >> >> I would like to know everything that is in the heap. >> >> We are here speaking of C*1.1.6 >> >> Theory : >> >> - Memtable (1024 MB) >> - Key Cache (100 MB) >> - Row Cache (disabled, and serialized with JNA activated anyway, so >> should be off-heap) >> - BloomFilters (about 1,03 GB - from cfstats, adding all the "Bloom >> Filter Space Used" and considering they are showed in Bytes - 1103765112) >> - Anything else ? >> >> So my heap should be fluctuating between 1,15 GB and 2.15 GB and growing >> slowly (from the new BF of my new data). >> >> My heap is actually changing from 3-4 GB to 6 GB and sometimes growing to >> the max 8 GB (crashing the node). >> >> Because of this I have an unstable cluster and have no other choice than >> use Amazon EC2 xLarge instances when we would rather use twice more EC2 >> Large nodes. >> >> What am I missing ? >> >> Practice : >> >> Is there a way not inducing any load and easy to do to dump the heap to >> analyse it with MAT (or anything else that you could advice) ? >> >> Alain >> > >
