pingcap/tidb

Splitting Test Directories to Increase Test Concurrency and Optimize Cache

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#44,940 opened on Jun 26, 2023

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good first issuetype/enhancement

Description

Enhancement

we are using Bazel's shard_count to increase test concurrency and speed up our testing process. However, in some cases, we have found that certain directories have too many tests, which can result in slower test execution times, decreased efficiency, and less optimized cache usage.

To address this issue, we need to split the test directories into smaller, more manageable chunks. This will help increase test concurrency, optimize cache usage, and ultimately improve our testing process.

Contributor guide

Tech stack
go
Domain
testing
Issue type
refactor
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.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Go programming experienceFamiliarity with Bazel build systemUnderstanding of test concurrency and cache optimization
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Investigate the current test directory structure in the repository, focusing on directories with a large number of test files. Examine the Bazel BUILD files to understand how shard count is currently configured. Propose a plan to split large test directories into smaller subdirectories, ensuring that each new directory maintains proper test isolation and coverage. Consider the impact on CI and cache efficiency.