Rsocket - Reactive Cassandra less throughput compared to blocking http

[pckeyan]

My use case revolves around retrieving the data from Cassandra using RSocket-Java in a non-blocking way. I use reactive cassandra template built on top of reactor-core. Throughput I see is very low in the range of 300 RPS compared to blocking http calls(800 RPS). If I remove Cassandra and use stub, I am getting close to 5000 rps. Can you please let me know whether RSocket-Java is not a perfect fit for above use cases? Sample non-blocking code is written similar to
“https://github.com/OlegDokuka/rsocket-issue-717/tree/master/src/main/java/com/rsocket/examples 1” and Cassandra Connections are configured as mentioned here - “https://dzone.com/articles/reactive-streams-with-spring-data-cassandra”. Please help and advise.

[OlegDokuka]

Hey @pckeyan.

Can you please share your benchmark setup or a simple project which let me reproduce your issue | understand the setup behavior?

Cheers,
Oleh

[pckeyan]

Hi @OlegDokuka,

I used directly into my business service, Let me try to peel it out. But from the environment standpoint, I used one Cassandra Docker container running on AWS EC2 - c5n.18xlarge. Same Backend Codebase to connect to Cassandra.

http Rest Call (API) - 800 TPS
Non Blocking Http (API) - 1600 TPS
RSocket(One Connection/Server) Connection Cache at Client - 300 TPS

I used the same code we tested on Issue 177 as mentioned above and I am using the Reactive Spring Cassandra with Datastax driver.

[OlegDokuka]

I'm asking because of different prefetch setup which may vary between reactive and blocking implementations in Spring.

Also, you point to a sample project, but it would be much better to have a simple client which can show RPS per a client

[pckeyan]

Definitely let me put together one for you to check. But if I remove the Cassandra and mock the data, I am getting ~5000 TPS. Something is blocking to Cassandra.

[OlegDokuka]

So, if you look at my slides on reactive database access, and in particular on the slide 33, which shows how reactive Cassandra works underneath, you may get an idea, why it may be slow, especially if backpressure is applied

[pckeyan]

Thank You, Let me go through the slide and will get back to you.

[pckeyan]

@OlegDokuka I tried to modify the fetchSize it has no effect. Let me try to get a sample for you to check.

[OlegDokuka]

@pckeyan any updates?

[pckeyan]

@OlegDokuka I tested with different parameters and I do not see any improvement. If you wish we can close this issue for now. I will reopen once I have a sample because I was testing this in my business application.

[OlegDokuka]

@pckeyan marking as need information. Feel free to provide a sample when it is ready

[pckeyan]

@OlegDokuka I added you as.a collaborator to my private projects. Please check this readMe for instructions. https://github.com/pckeyan/rsocket-load-balancer/blob/master/README.md. Please let me know your feedback.

[OlegDokuka]

@pckeyan looking

[pckeyan]

Hi @OlegDokuka, Any findings so far?