jaegertracing/jaeger

Improve unit test speed

Open

#6,111 opened on Oct 22, 2024

View on GitHub
 (25 comments) (0 reactions) (0 assignees)Go (18,974 stars) (2,326 forks)batch import
good first issuehelp wantedperformance

Description

This blog post provides a good background / introduction: https://threedots.tech/post/go-test-parallelism/

When I ran the following command

GOMAXPROCS=1 go test -parallel 128 -p 16 -json ./... | go run github.com/roblaszczak/vgt@latest

I got the following output:

Image

It shows some tests running for a very long time (the darker blue colors), but even of some of them were sped up there are others (like in the first group in top left corner) that are still relatively long.

We also almost never use t.Parallel() in our test (right now I only found one instance), even though many of our tests are starting servers and making network calls, so could benefit from parallelism. But adding t.Parallel() should be done with care - some tests are starting servers on the same port (instead of ephemeral port) and must be refactored before adding parallelism.

Contributor guide

Tech stack
go
Domain
testingperformance
Issue type
performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Go testing basicsunderstanding of t.Parallel()knowledge of Jaeger's test setupavoiding port conflicts
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
55
Research direction
Start by running the test suite with GOMAXPROCS=1 and the suggested command to identify slow tests. Focus on tests that start servers or make network calls and are not using ephemeral ports. Review existing comments in the issue for specific tests that have been discussed. Then add t.Parallel() to safe tests and refactor those using fixed ports to avoid races.
Improve unit test speed · jaegertracing/jaeger#6111 | Good First Issue