Experiment with concurrency levels

[adespawn]

Refs: #73

With planned changes that touch the concurrency, we would want to see the driver performance across different concurrency levels.

This PR introduces a refactor to the current benchmarks, which would allow us to add benchmarks parameterised on the concurrency level easily, and adds those benchmarks.

I would recommend reviewing the first commit in vscode (or similar), to better see what changes and what's kept unchanged

Introduces changes that were generated with LLM.

Example results [with not yet published PR] (x axis is the concurrency level on the benchmark) - I need to add beter labeling support to the benchmarking tool)

[Copilot]

Pull request overview

Refactors the JS benchmark harness to support easily parameterizing concurrency level (for planned concurrency-related driver changes) and adds new “fixed query count / variable concurrency” benchmark variants.

Changes:

• Introduces a centralized JS benchmark entrypoint (benchmark/logic/benchmark.js) and updates existing benchmark modules to export a common function signature.
• Updates benchmarker runner configs and wrapper scripts to call the centralized entrypoint (benchmark names no longer include .js).
• Adds new *_fixed benchmark variants in runner configs to sweep concurrency levels while keeping query count fixed.

Reviewed changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
benchmark/runner-config/scylladb-driver/config.yml	Switches backend commands to the centralized benchmark entrypoint; adds *_fixed variants.
benchmark/runner-config/cassandra-driver/config.yml	Same as above for the cassandra-driver backend; adds *_fixed variants.
benchmark/runner-config/run-js-benchmark.sh	Wrapper now calls benchmark/logic/benchmark.js with <driver> <benchmark-name> <N>.
benchmark/runner-config/run-js-benchmark-fixed.sh	New wrapper for concurrency-sweep scenarios (step controls concurrency).
benchmark/runner-config/config.yml	Adds benchmark definitions for *_fixed variants and adjusts default run count.
benchmark/logic/benchmark.js	New centralized dispatcher that loads the driver, creates a client, and invokes the selected benchmark module.
benchmark/logic/insert.js	Converted to exported benchmark function with default step count.
benchmark/logic/concurrent_insert.js	Converted to exported benchmark function; now accepts concurrencyLevel.
benchmark/logic/select.js	Converted to exported benchmark function delegating to parametrized_select.
benchmark/logic/parametrized_select.js	Refactored to accept (cassandra, client, rowCount, stepCount) rather than argv.
benchmark/logic/large_select.js	Converted to exported benchmark function delegating to parametrized_select.
benchmark/logic/paging.js	Converted to exported benchmark function with default step count.
benchmark/logic/concurrent_paging.js	Converted to exported benchmark function; now takes runner-provided concurrencyLevel.
benchmark/logic/batch.js	Converted to exported benchmark function; clarifies batch-size constant naming/comment.
benchmark/logic/deser.js	Converted to exported benchmark function with default step count.
benchmark/logic/concurrent_deser.js	Converted to exported benchmark function; now accepts concurrencyLevel.
benchmark/logic/ser.js	Converted to exported benchmark function with default step count.
benchmark/logic/concurrent_ser.js	Converted to exported benchmark function; now accepts concurrencyLevel.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.