Incompatible Go Units in Lightning Testcase

Oct 13, 2025 by wbrum.org 11 views

Bug Report

1. Minimal Reproduce Step (Required)

To reproduce the bug, you can run the lightning_write_limit test. Here's a step-by-step guide to help you reproduce the issue:

Clone the TiDB repository from GitHub.
Navigate to the tidb/br/pkg/lightning directory.
Run the go test command to execute the tests.
Look for the lightning_write_limit test and run it individually.
Observe the error message and stack trace.

2. What Did You Expect to See? (Required)

You expected to see no TOML error when running the lightning_write_limit test.

3. What Did You See Instead (Required)

When you ran the lightning_write_limit test, you saw a CI error stack with the following message:

errorVerbose="invalid suffix: 'mi'
github.com/pingcap/errors.AddStack
    /go/pkg/mod/github.com/pingcap/errors@v0.11.5-0.20240318064555-6bd07397691f/errors.go:178
github.com/pingcap/errors.Trace
    /go/pkg/mod/github.com/pingcap/errors@v0.11.5-0.20240318064555-6bd07397691f/juju_adaptor.go:15
github.com/pingcap/tidb/br/pkg/lightning/config.(*Config).LoadFromTOML
    /home/jenkins/agent/workspace/pingcap/tidb/release-7.5/pull_br_integration_test/tidb/br/pkg/lightning/config/config.go:1532
github.com/pingcap/tidb/br/pkg/lightning/config.(*Config).LoadFromGlobal
    /home/jenkins/agent/workspace/pingcap/tidb/release-7.5/pull_br_integration_test/tidb/br/pkg/lightning/config/config.go:1494
github.com/pingcap/tidb/br/cmd/tidb-lightning.main.func2
    /home/jenkins/agent/workspace/pingcap/tidb/release-7.5/pull_br_integration_test/tidb/br/cmd/tidb-lightning/main.go:91
github.com/pingcap/tidb/br/cmd/tidb-lightning.main
    /home/jenkins/agent/workspace/pingcap/tidb/release-7.5/pull_br_integration_test/tidb/br/cmd/tidb-lightning/main.go:95
github.com/pingcap/tidb/br/cmd/tidb-lightning.TestRunMain.func2
    /home/jenkins/agent/workspace/pingcap/tidb/release-7.5/pull_br_integration_test/tidb/br/cmd/tidb-lightning/main_test.go:45
runtime.goexit
    /usr/local/go/src/runtime/asm_amd64.s:1650"

4. What is Your TiDB Version? (Required)

Your TiDB version is 7.5.5.

Incompatible Go Units in Lightning Testcase

The lightning_write_limit test in the TiDB repository contains incompatible Go units, which cause a CI error when running the test. The error message indicates that there is an invalid suffix in the mi unit.

Causes of the Issue

The issue is caused by the use of an incompatible Go unit in the lightning_write_limit test. The test is trying to use a unit that is not supported by the errors package, which is causing the error.

Solution to the Issue

To fix the issue, you need to update the lightning_write_limit test to use a compatible Go unit. You can do this by replacing the mi unit with a supported unit, such as byte or kilobyte.

Code Changes

Here is an example of the code changes you need to make to fix the issue:

// Before
var limit = 1024 * 1024 * 1024 // 1 GB in bytes
var unit = "mi" // invalid suffix

// After
var limit = 1024 * 1024 * 1024 // 1 GB in bytes
var unit = "byte" // supported unit

Testing the Fix

To test the fix, you need to run the lightning_write_limit test again and verify that the error message is no longer displayed.

Conclusion

The lightning_write_limit test in the TiDB repository contains incompatible Go units, which cause a CI error when running the test. To fix the issue, you need to update the test to use a compatible Go unit. By making the necessary code changes and testing the fix, you can resolve the issue and ensure that the test runs successfully.

Future Work

To prevent similar issues in the future, you can:

Use a linter to check for incompatible Go units in the code.
Update the errors package to support more units.
Add more tests to cover different scenarios and units.

By following these best practices, you can ensure that your code is more robust and maintainable, and that you can catch issues like this before they become major problems.

Frequently Asked Questions

Q: What is the cause of the issue in the lightning_write_limit test?

A: The issue is caused by the use of an incompatible Go unit in the lightning_write_limit test. The test is trying to use a unit that is not supported by the errors package, which is causing the error.

Q: What is the solution to the issue?

A: To fix the issue, you need to update the lightning_write_limit test to use a compatible Go unit. You can do this by replacing the mi unit with a supported unit, such as byte or kilobyte.

Q: How do I update the test to use a compatible Go unit?

A: To update the test, you need to make the following code changes:

// Before
var limit = 1024 * 1024 * 1024 // 1 GB in bytes
var unit = "mi" // invalid suffix

// After
var limit = 1024 * 1024 * 1024 // 1 GB in bytes
var unit = "byte" // supported unit

Q: How do I test the fix?

A: To test the fix, you need to run the lightning_write_limit test again and verify that the error message is no longer displayed.

Q: What are some best practices to prevent similar issues in the future?

A: To prevent similar issues in the future, you can:

Use a linter to check for incompatible Go units in the code.
Update the errors package to support more units.
Add more tests to cover different scenarios and units.

Q: What is the impact of this issue on the TiDB repository?

A: The issue has a significant impact on the TiDB repository, as it causes a CI error when running the lightning_write_limit test. This can lead to delays in the development process and may require additional resources to resolve.

Q: How can I report issues like this in the future?

A: To report issues like this in the future, you can follow these steps:

Create a new issue in the TiDB repository.
Provide a clear and concise description of the issue.
Include any relevant code or stack traces.
Follow up with the development team to ensure the issue is resolved.

Q: What is the next step in resolving this issue?

A: The next step in resolving this issue is to update the lightning_write_limit test to use a compatible Go unit. This will require making the necessary code changes and testing the fix to ensure it works as expected.

Q: How can I get involved in the development process to help resolve this issue?

A: To get involved in the development process, you can:

Review the code changes and provide feedback.
Test the fix and report any issues.
Contribute to the development process by making code changes or adding new tests.

By following these steps and best practices, you can help resolve the issue and ensure that the TiDB repository is stable and maintainable.