Num_replica affect on read/write performance

Hi there, I’m testing different CKDB setups and was wondering what kind of impact does replication have on the read/write performance of a cluster? Say for example I had a 9 node cluster and I set the num_replicas to 9 as opposed to 3, does that have any significant impact on the performance of the cluster?

Hey @Jeongp,

Yes, setting num_replicas to 9 would impact your cluster in terms of latency.

The reasoning here is that many operations, most notably writes, require a quorum of replicas to commit the action.

If you have 3 replicas, only 2 replicas suffice to acknowledge the task.

If you have 9 replicas, you will need 5 replicas to acknowledge the task (more hopping).

Let me know if you have any other questions.

Thanks,
Matt

Hi Matt, thanks for the reply!

I’m trying to benchmark what kind of impact the increased replica will have on our DB performance, and ran into this page, but the workload binary seems to require the hosts to be on google cloud?

Are there other documentations that describe running a benchmark on a cluster running on arbitrary ubuntu hosts?

Thanks,
Jeong

Hey @Jeongp, no problem at all.

I believe this is what you’re looking for.

Let me know if you have any other questions.

Thanks,
Matt

Perfect, thanks Matt!

My pleasure, good luck!