Question 1

How do I set up a basic HTTP load test with rlt?

Accepted Answer

Use the provided examples like http_reqwest or http_hyper, implement the BenchSuite trait with your client logic, and run it with CLI options such as --url and --concurrency. The README shows code snippets for stateless and stateful benchmarks to get started quickly.

Question 2

What's the difference between rlt and Apache JMeter?

Accepted Answer

rlt is a Rust-based framework requiring code implementation but offers higher performance and flexibility for custom protocols, while JMeter is a Java-based GUI tool with out-of-the-box support but can be heavier. rlt is better for Rust-integrated, code-first workflows, whereas JMeter suits visual test design.

Question 3

How can I use rlt to test a gRPC service?

Accepted Answer

Implement a custom BenchSuite trait that uses gRPC clients, similar to the HTTP examples, by defining worker state for connections and benchmarking logic. Since rlt is protocol-agnostic, you'll need to integrate gRPC Rust crates and handle serialization manually.

Question 4

How to fail a CI pipeline on performance regression with rlt?

Accepted Answer

Use the --fail-on-regression CLI option with --baseline to compare against saved results, and customize metrics with --regression-metrics. This integrates directly into scripts, as documented in the CI/CD section, to exit with an error on degradations.

Question 5

What kind of statistics does rlt provide during a test?

Accepted Answer

rlt collects metrics like latency percentiles, success ratios, bytes transferred, and iteration counts, displayed in real-time via the TUI or output as JSON. The statistics are detailed in the reports and can be used for baseline comparisons.

Question 6

Is rlt suitable for load testing databases like MySQL?

Accepted Answer

Yes, through custom BenchSuite implementations, as shown in the PostgreSQL example. You'll need to set up database connections per worker and write query logic, but rlt handles concurrency and metrics collection efficiently.

Question 7

How to customize the TUI in rlt?

Accepted Answer

The TUI is built-in and not highly customizable; it uses a fixed layout inspired by oha. For advanced modifications, you'd need to fork the project or rely on the provided options like --fps and --quit-manually, as the framework prioritizes simplicity over UI flexibility.

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