Setup Cassandra benchmark env and add CQLMultiQueryBenchmark

[li-boxuan]

Currently, all our benchmarks are using the in-memory backend. This PR sets up the infrastructure for Cassandra-based benchmarks and adds a multi-query benchmark using the CQL backend.

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[li-boxuan]

I tried many many times and the CI only worked with my custom changes to ccm. The upstream PR is here.

[farodin91]

Just interest. Why didn't you use testcontainers for the cql tests?

[li-boxuan]

Why didn't you use testcontainers for the cql tests?

That's a good question. I guess we could use test containers, but IIUC it does not support multiple Cassandra instances. ccm gives us more flexibility in the Cassandra cluster setup. It is also the tool used by Cassandra's official distributed test suite. Also, I am not sure but I suspect using Cassandra in docker would bring additional overhead that might affect the stability of benchmark results. But yeah, there is no strong reason against testcontainers.

[li-boxuan]

This is a blocker for #2942

[rngcntr]

Hi @li-boxuan, thanks for your PR!

[rngcntr]

How about adding the USE_MULTIQUERY flag as a @Param to provide some insights to the performance boost multi query brings?

[li-boxuan]

That's a good idea, but unfortunately, it will take much much longer time (a few hours) for the benchmark to finish. I have tried it manually and (as we would expect) USE_MULTIQUERY = true makes the queries much much faster.

[rngcntr]

Ouch, I didn't expect the time to be on the scale of hours. In this case, I think it's fine as it is.

[li-boxuan]

@farodin91 Do you want to review again?