Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

fix(storev2/snapshots): Close StateChanges channel in doRestoreSnapshot #21106

Merged
merged 10 commits into from
Aug 2, 2024

Conversation

hieuvubk
Copy link
Contributor

@hieuvubk hieuvubk commented Jul 29, 2024

Description

Closes: #XXXX

We pass state change to a channel in commitSnapshotter.Restore then read it in storageSnapshotter.Restore. Seem like the channel does not close, got an infinity loop in storage restore.

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

  • included the correct type prefix in the PR title, you can find examples of the prefixes below:
  • confirmed ! in the type prefix if API or client breaking change
  • targeted the correct branch (see PR Targeting)
  • provided a link to the relevant issue or specification
  • reviewed "Files changed" and left comments if necessary
  • included the necessary unit and integration tests
  • added a changelog entry to CHANGELOG.md
  • updated the relevant documentation or specification, including comments for documenting Go code
  • confirmed all CI checks have passed

Reviewers Checklist

All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.

Please see Pull Request Reviewer section in the contributing guide for more information on how to review a pull request.

I have...

  • confirmed the correct type prefix in the PR title
  • confirmed all author checklist items have been addressed
  • reviewed state machine logic, API design and naming, documentation is accurate, tests and test coverage

Summary by CodeRabbit

  • Bug Fixes
    • Improved resource management by ensuring proper closure of channels, preventing potential leaks and enhancing function robustness.
  • Refactor
    • Revised error handling and channel lifecycle management in the snapshot restoration process to improve concurrency management and operational efficiency.

@hieuvubk hieuvubk requested a review from a team as a code owner July 29, 2024 12:22
Copy link
Contributor

coderabbitai bot commented Jul 29, 2024

Walkthrough

Walkthrough

The recent changes involve modifications to channel management in the CommitStore and Manager classes. A defer close(chStorage) statement was added in the Restore function to ensure proper closure of the channel. In contrast, the doRestoreSnapshot method removed this statement, allowing the channel to remain open longer. These adjustments aim to improve resource management and error handling during snapshot restoration, enhancing the robustness of the overall system.

Changes

Files Change Summary
store/v2/commitment/store.go Added defer close(chStorage) in the Restore function to ensure proper channel closure.
store/v2/snapshots/manager.go Removed defer close(chStorage) from doRestoreSnapshot, impacting channel lifecycle and simplifying error handling.

Thank you for using CodeRabbit. We offer it for free to the OSS community and would appreciate your support in helping us grow. If you find it useful, would you consider giving us a shout-out on your favorite social media?

Share
Tips

Chat

There are 3 ways to chat with CodeRabbit:

  • Review comments: Directly reply to a review comment made by CodeRabbit. Example:
    • I pushed a fix in commit <commit_id>.
    • Generate unit testing code for this file.
    • Open a follow-up GitHub issue for this discussion.
  • Files and specific lines of code (under the "Files changed" tab): Tag @coderabbitai in a new review comment at the desired location with your query. Examples:
    • @coderabbitai generate unit testing code for this file.
    • @coderabbitai modularize this function.
  • PR comments: Tag @coderabbitai in a new PR comment to ask questions about the PR branch. For the best results, please provide a very specific query, as very limited context is provided in this mode. Examples:
    • @coderabbitai generate interesting stats about this repository and render them as a table.
    • @coderabbitai show all the console.log statements in this repository.
    • @coderabbitai read src/utils.ts and generate unit testing code.
    • @coderabbitai read the files in the src/scheduler package and generate a class diagram using mermaid and a README in the markdown format.
    • @coderabbitai help me debug CodeRabbit configuration file.

Note: Be mindful of the bot's finite context window. It's strongly recommended to break down tasks such as reading entire modules into smaller chunks. For a focused discussion, use review comments to chat about specific files and their changes, instead of using the PR comments.

CodeRabbit Commands (invoked as PR comments)

  • @coderabbitai pause to pause the reviews on a PR.
  • @coderabbitai resume to resume the paused reviews.
  • @coderabbitai review to trigger an incremental review. This is useful when automatic reviews are disabled for the repository.
  • @coderabbitai full review to do a full review from scratch and review all the files again.
  • @coderabbitai summary to regenerate the summary of the PR.
  • @coderabbitai resolve resolve all the CodeRabbit review comments.
  • @coderabbitai configuration to show the current CodeRabbit configuration for the repository.
  • @coderabbitai help to get help.

Additionally, you can add @coderabbitai ignore anywhere in the PR description to prevent this PR from being reviewed.

CodeRabbit Configuration File (.coderabbit.yaml)

  • You can programmatically configure CodeRabbit by adding a .coderabbit.yaml file to the root of your repository.
  • Please see the configuration documentation for more information.
  • If your editor has YAML language server enabled, you can add the path at the top of this file to enable auto-completion and validation: # yaml-language-server: $schema=https://coderabbit.ai/integrations/schema.v2.json

Documentation and Community

  • Visit our Documentation for detailed information on how to use CodeRabbit.
  • Join our Discord Community to get help, request features, and share feedback.
  • Follow us on X/Twitter for updates and announcements.

Copy link
Contributor

@hieuvubk your pull request is missing a changelog!

Copy link
Contributor

@coderabbitai coderabbitai bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Actionable comments posted: 0

Review details

Configuration used: .coderabbit.yml
Review profile: CHILL

Commits

Files that changed from the base of the PR and between 5853356 and 0f63965.

Files selected for processing (2)
  • store/v2/commitment/store.go (1 hunks)
  • store/v2/snapshots/manager.go (1 hunks)
Additional context used
Path-based instructions (2)
store/v2/commitment/store.go (1)

Pattern **/*.go: Review the Golang code for conformity with the Uber Golang style guide, highlighting any deviations.

store/v2/snapshots/manager.go (1)

Pattern **/*.go: Review the Golang code for conformity with the Uber Golang style guide, highlighting any deviations.

Additional comments not posted (1)
store/v2/commitment/store.go (1)

317-318: Ensure channel usage after closure is safe.

The defer close(chStorage) statement ensures that the channel is closed when the function exits, preventing resource leaks. Ensure that the channel chStorage is not used after it is closed to avoid potential panics.

Copy link
Contributor

@coderabbitai coderabbitai bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Actionable comments posted: 2

Review details

Configuration used: .coderabbit.yml
Review profile: CHILL

Commits

Files that changed from the base of the PR and between 0f63965 and ee1ee6e.

Files selected for processing (2)
  • store/v2/commitment/store.go (1 hunks)
  • store/v2/snapshots/manager.go (2 hunks)
Files skipped from review due to trivial changes (1)
  • store/v2/commitment/store.go
Additional context used
Path-based instructions (1)
store/v2/snapshots/manager.go (1)

Pattern **/*.go: Review the Golang code for conformity with the Uber Golang style guide, highlighting any deviations.

Comment on lines 422 to 423
if commitmentErr != nil {
return commitmentErr
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Synchronize error handling with the new goroutine.

The current check for commitmentErr will not work correctly because the goroutine might not have finished executing. Use a channel to synchronize error handling.

-  if commitmentErr != nil {
-    return commitmentErr
+  if err := <-commitmentErrCh; err != nil {
+    return err
  }
Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
if commitmentErr != nil {
return commitmentErr
if err := <-commitmentErrCh; err != nil {
return err

Comment on lines 413 to 421
var commitmentErr error
go func() {
defer close(chStorage)
nextItem, err = m.commitSnapshotter.Restore(snapshot.Height, snapshot.Format, streamReader, chStorage)
if err != nil {
commitmentErr = err
}
}()

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Ensure proper error handling and resource management.

The new goroutine introduced for handling the restoration process captures errors in commitmentErr. However, commitmentErr is checked immediately after the goroutine is started, which might not capture errors correctly. Consider using a channel to synchronize error handling.

-  var commitmentErr error
-  go func() {
-    defer close(chStorage)
-    nextItem, err = m.commitSnapshotter.Restore(snapshot.Height, snapshot.Format, streamReader, chStorage)
-    if err != nil {
-      commitmentErr = err
-    }
-  }()
+  commitmentErrCh := make(chan error, 1)
+  go func() {
+    defer close(chStorage)
+    _, err := m.commitSnapshotter.Restore(snapshot.Height, snapshot.Format, streamReader, chStorage)
+    commitmentErrCh <- err
+  }()
Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
var commitmentErr error
go func() {
defer close(chStorage)
nextItem, err = m.commitSnapshotter.Restore(snapshot.Height, snapshot.Format, streamReader, chStorage)
if err != nil {
commitmentErr = err
}
}()
var commitmentErrCh = make(chan error, 1)
go func() {
defer close(chStorage)
nextItem, err = m.commitSnapshotter.Restore(snapshot.Height, snapshot.Format, streamReader, chStorage)
commitmentErrCh <- err
}()

@hieuvubk hieuvubk marked this pull request as draft July 30, 2024 05:52
@hieuvubk hieuvubk marked this pull request as ready for review July 30, 2024 07:26
Copy link
Contributor

@coderabbitai coderabbitai bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Actionable comments posted: 0

Review details

Configuration used: .coderabbit.yml
Review profile: CHILL

Commits

Files that changed from the base of the PR and between ee1ee6e and fcf65d5.

Files selected for processing (1)
  • store/v2/snapshots/manager.go (2 hunks)
Files skipped from review as they are similar to previous changes (1)
  • store/v2/snapshots/manager.go

}
close(chStorage)
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Lets add a comment so it doesn't get linted away in a future refactor

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I don't fully follow which problem is fixed here? could you please add some test cases?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It's hard to present it as a unit test, but u can try this scripts

My understanding is in storage.Restore we loop through the channel:

for kvPair := range chStorage {

This loop never ends until the channel is closed.

chStorage := make(chan *corestore.StateChanges, defaultStorageChannelBufferSize)
defer close(chStorage)

storageErrs := make(chan error, 1)
go func() {
  defer close(storageErrs)
  err := m.storageSnapshotter.Restore(snapshot.Height, chStorage)
  if err != nil {
	  storageErrs <- err
  }
}()

nextItem, err = m.commitSnapshotter.Restore(snapshot.Height, snapshot.Format, streamReader, chStorage)

...

// wait for storage snapshotter to complete
if err := <-storageErrs; err != nil {
  return errorsmod.Wrap(err, "storage snapshotter")
}

With our current implement, close(chStorage) not be called => loop never ends

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This means there are no test cases to check this restoring flow.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

i think its because the mockStorageSnapshotter we use in restore test doesn't do anything, let me update that in my test PR

Copy link
Contributor

@coderabbitai coderabbitai bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Actionable comments posted: 0

Review details

Configuration used: .coderabbit.yml
Review profile: CHILL

Commits

Files that changed from the base of the PR and between fcf65d5 and c6008e8.

Files selected for processing (1)
  • store/v2/snapshots/manager.go (2 hunks)
Files skipped from review as they are similar to previous changes (1)
  • store/v2/snapshots/manager.go

}
close(chStorage)
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This means there are no test cases to check this restoring flow.

@hieuvubk hieuvubk enabled auto-merge August 1, 2024 14:00
Copy link
Contributor

@coderabbitai coderabbitai bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Actionable comments posted: 0

Review details

Configuration used: .coderabbit.yml
Review profile: CHILL

Commits

Files that changed from the base of the PR and between c6008e8 and 7153fa9.

Files selected for processing (1)
  • store/v2/snapshots/manager.go (2 hunks)
Files skipped from review as they are similar to previous changes (1)
  • store/v2/snapshots/manager.go

@hieuvubk hieuvubk disabled auto-merge August 1, 2024 17:52
@hieuvubk hieuvubk enabled auto-merge August 1, 2024 18:14
@hieuvubk hieuvubk disabled auto-merge August 2, 2024 07:19
@hieuvubk hieuvubk added this pull request to the merge queue Aug 2, 2024
Merged via the queue into main with commit bc72e34 Aug 2, 2024
75 checks passed
@hieuvubk hieuvubk deleted the hieu/snapshots-restore branch August 2, 2024 09:53
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
Projects
None yet
Development

Successfully merging this pull request may close these issues.

5 participants