Re: cassandra cluser sizing

2018-07-17 Thread Jeff Jirsa
Depends on whether or not you’re seeing overlaps (do you have read repairs messing up the windows? Do you expire cleanly? Do you do non-ttl deletes?) When I wrote it I used to run about 70-80% full, but we were willing to do some manual cleanup when overlaps prevented dropping full sstables --

Re: cassandra cluser sizing

2018-07-17 Thread Eunsu Kim
Can I ask you an additional question here? How much free space should I have if most tables use TimeWindowCompactionStrategy? > On 13 Jul 2018, at 10:09 PM, Vitaliy Semochkin wrote: > > Jeff, thank you very much for reply. > Will try to use 4TB per instance. > > If I understand it correctly

Re: cassandra cluser sizing

2018-07-13 Thread Vitaliy Semochkin
Jeff, thank you very much for reply. Will try to use 4TB per instance. If I understand it correctly level compaction can lead to 50% https://docs.datastax.com/en/dse-planning/doc/planning/planningHardware.html Regarding the question of running multiple instances per server, am I correct that in c

Re: cassandra cluser sizing

2018-07-12 Thread Jeff Jirsa
You can certainly go higher than a terabyte - 4 or so is common, Ive heard of people doing up to 12 tb with the awareness that time to replace scales with size on disk, so a very large host will take longer to rebuild than a small host The 50% free guidance only applies to size tiered compaction