I've been doing some basic performance testing of batch commitlog on 2.0.15, 2.1-head, and 2.2.-head. I have been seeing very odd results where 2.0.15 performance is incredibly high, suspiciously so, when compared to 2.1 or 2.2.
I'm using the following yaml options:
I am able to reproduce this on two separate clusters, physical hardware, with SSDs. I have not been able to reproduce this on gce, or a physical cluster I have access to with HDD. I can reproduce this consistently, with different stress options, and with higher data load on the nodes. I can also reproduce this myself on these machines, without using the C* perf tool to set up the cluster and perform the operations.
When running 2.0.15 batch commitlog vs periodic, I do see a difference as expected:
I am using the newest stress code on trunk. What should I be looking for to explain the anomalous performance here?