I’m currently evaluationg aerospike using ycsb based on the article at http://www.aerospike.com/blog/aerospike-doubles-in-memory-nosql-database-performance/
I’ve been evaluating multiple configurations, mostly with 2 replicas on 2 servers(2*6 core hyperthreading disabled, 96gb, ran ). We have up to 4 identical machines(with hyperthreading on) available as clients in the same rack, and are getting reasonably good performance(400k tps on workload B in pure memory which is 95/5 R/W). Initial configuration was done with afterburner.sh and trying to adjust settings manually has resulted in worse performance so I assume the settings are good.
I am currently concerned with the fact that as we increase clients performance is downgrading quite significantly. With a peak of roughly 150k tps on 50/50 R/W using 3 clients, we drop to 100k when using 4 clients. I have investigated the network as a possible cause and am finding no dropped packets. Aerospike logs are also not showing anything unusual. top, iotop, ifconfig do not seem to indicate cpu or network as a cause of the slowdown.
Is performance degradation to be expected as we surpass the maximum throughput for a configuration?
Also, any possible explanation as to why we are not seeing figures close to those in the aforementioned article?