Forum: Building VoltDB Applications

Post: Cpu usage is not 100%, Is there any way to improve tps?

Cpu usage is not 100%, Is there any way to improve tps?
tomg
Aug 20, 2016
I run voltkv app which be in <voltdbroot>/examples/voltkv. three vmware virtual machine, 8 core, 32GB mem.
Deployment file:
<?xml version="1.0"?>
<deployment>
<cluster hostcount="3" sitesperhost="4" kfactor="1" />
<commandlog enabled="false" />
<snapshot enabled="false" />
</deployment>

when (modify function async-benchmark in run.sh) maxvaluesize=128, minvaluesize=128, servers=localhost, tps=53687

when use servers=ip1,ip2,ip3 connect to all hosts, tps=83253, cpu usage=46%, network traffic = 17MB/s.

cpu usage is not 100%, Is there any way to improve tps?
bballard
Aug 23, 2016
You can increase sitesperhost to get more SQL execution engines running in parallel. We have guidelines for benchmarking and finding the optimal sitesperhost setting in the Planning Guide, Chapter 5 (https://docs.voltdb.com/PlanningGuide/BenchmarkSites.php)

With 8 cores, you may get better throughput with 8 or more sites per host.

Also, keep in mind that VoltDB is primarily putting data in memory and accessing it, not running CPU-intensive calculations, so it very often could reach the maximum speed of an I/O bus before the CPUs reach 100%.