Nodetool compactionstats Regarding cassandra-stress, make sure that you initiate load outside of database subnet
Subroto > On Jul 14, 2017, at 3:02 PM, Roger Warner <rwar...@pandora.com> wrote: > > 30G java heap. The dataset is the usual Cassandra-test size > > How do I tell if compaction has completed? > > I will add more iterations/time to the test. > > Thank you > > > > > Date: Friday, July 14, 2017 at 2:21 PM > To: Roger Warner <rwar...@pandora.com> > Subject: Re: Reversed read write performance. > > Pls add info about caching. Probably your reads are cached (what's the > dataset size?). > Pls also make sure that you run these tests after previous compaction > finished and run > them long enough (even few hours). > > Cheers, > d...@scylladb.com > > On Sat, Jul 15, 2017 at 12:11 AM, Roger Warner <rwar...@pandora.com> wrote: > I’m confused about read vs write performance. I was expecting to see higher > write than read perf. I’m seeing the opposite by nearly 2X > Please help. Am I doing/configuring something wrong or do I have the wrong > expectations. I am very new to Cassandra. And this is not using Datastax. > . > > I have a new cluster I’m trying to estimate capacity of. > · 6 nodes, 2 datacenters, 3:3 – but on the same physical network as > of now > > · 500G SATA SSD drives benched at 250MB/s on these machines > > · 32 core, 2Ghz, 60G of RAM / node > > · Cassandra 3.11 > > > Cassandra-stress being run on the same build as these. > · Cl=LOCAL_ONE > > · Mixed test 4:1 > > · Defaults otherwise > > · Testing using –nodes from dci. > > > Schema > · Tweaked Cassandra-stress schema > > · NetworkToplogyStragety > > · 2 DC > > · 3 replicas > > · SizeTieredCompactionStrategy > > > > > I’ve run 4:1 read to write I see ~325Kops/s > I see about write to read I see ~150Kops/s > > Any suggestions a very much appreciated. >
