50% disk free is really only required with STCS (in size tiered compaction, if you have 4 files of a similar size, they'll be joined together - there are theoretically times when all of your data is in 4 files of the same size, and to join them together you'll temporarily double your disk space). With LCS (and TWCS), you should be able to go to 70% or so, most of the time, because that "join everything together" compaction never happens in those strategies.
Keep an eye on CPU load and latencies - if you see it trending in the wrong direction beyond what you can tolerate in your SLA, you may want to consider scaling. On 2017-06-29 06:48 (-0700), Nitan Kainth <ni...@bamlabs.com> wrote: > Ideally you should maintain 50% disk space. > SLA and Node load is also very important to make the decision. > > > On Jun 29, 2017, at 6:45 AM, ZAIDI, ASAD A <az1...@att.com> wrote: > > > > Hello Folks, > > > > Iâm on Cassandra 2.2.8 cluster with 14 nodes , each with around 2TB of > > data volume. Iâm looking for a criteria /or data points that can help me > > decide when or if I should add more nodes to the cluster and by how many > > nodes. > > > > Iâll really appreciate if you guys can share your insights. > > > > Thanks/Asad > > --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org For additional commands, e-mail: user-h...@cassandra.apache.org
