I used oltpbenchmark and ran automated tests on hetzner cloud using Terraform and some automation scripts. The comparisons are based on the YCSB workloads executed by oltpbenchmark.
May I know how many instances are there in crdb/tidb cluster and the concurrency in the benchmark?
We found that for small clusters (for example 3 instances), CRDB could be fast in read-only workload. Because CRDB is single binary, about 1/3 read operation will not involve RPC. TiDB need to involve a RPC for every request. For larger scale cluster or high concurrency, it is a different story.
I tested clusters with between 3 and 12 nodes, and the differences were similar for the different sizes. I’m not sure how it performs for larger clusters than that though. Additionally, the results might have been a bit misleading on the large clusters because of the low scale factor, leading to higher contention on some rows.