The most data I put on a node with spinning disk is 1TB. What are the machine specs? Cpu, memory, etc and what is the read/write pattern-heavy ingest rate/heavy read rate and how ling do you keep data in the cluster?
-- Colin Clark +1 612 859 6129 Skype colin.p.clark > On Feb 8, 2015, at 2:44 PM, Jiri Horky <ho...@avast.com> wrote: > > Hi all, > > we are seeing quite high GC pressure (in old space by CMS GC Algorithm) > on a node with 4TB of data. It runs C* 1.2.18 with 12G of heap memory > (2G for new space). The node runs fine for couple of days when the GC > activity starts to raise and reaches about 15% of the C* activity which > causes dropped messages and other problems. > > Taking a look at heap dump, there is about 8G used by SSTableReader > classes in org.apache.cassandra.io.compress.CompressedRandomAccessReader. > > Is this something expected and we have just reached the limit of how > many data a single Cassandra instance can handle or it is possible to > tune it better? > > Regards > Jiri Horky
