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.

Sign up for GitHub

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

Already on GitHub? Sign in to your account

Jump to bottom

routing: repopulate missing edges in graph for local channels #8768

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

routing: repopulate missing edges in graph for local channels #8768

wants to merge 1 commit into from

Conversation

JssDWt
Copy link
Contributor

@JssDWt JssDWt commented May 20, 2024 •
edited

Change Description

Some channels missed corresponding edges in the graph database. This had a few implications:

  • lncli getchaninfo would return "edge not found"
  • forwarding htlcs over a channel with a missing edge would use the default channel policy
  • lncli updatechanpolicy would fail to the edge missing

This commit adds a flag to LND startup: repopulate-missing-edges. When LND is started with this flag, any missing edges will be prefilled in the database with the default routing policy. This allows the user to later update the channel policy of these channels.

Note that 784dc8d partly addresses the issue for new channels, but old channels were still affected by this issue.

Fixes #7261

Steps to Test

I'm not entirely sure how to test this properly yet. Have a database where the channel edge is missing. lncli getchaninfo should fail. Then run LND with the repopulate-missing-edges flag. It should fix the issue.

Pull Request Checklist

Testing

  • Your PR passes all CI checks.
  • Tests covering the positive and negative (error paths) are included.
  • Bug fixes contain tests triggering the bug to prevent regressions.

Code Style and Documentation

馃摑 Please see our Contribution Guidelines for further guidance.

@JssDWt
routing: repopulate missing edges in graph for local channels
c3b1d35 
Some channels missed corresponding edges in the graph database. This had a few
implications:
- `lncli getchaninfo` would return "edge not found"
- forwarding htlcs over a channel with a missing edge would use the default
  channel policy
- `lncli updatechanpolicy` would fail to the edge missing

This commit adds a flag to LND startup: `repopulate-missing-edges`. When LND is
started with this flag, any missing edges will be prefilled in the database with
the default routing policy. This allows the user to later update the channel
policy of these channels.

Note that 784dc8d partly addresses the issue
for new channels, but old channels were still affected by this issue.
@coderabbitai coderabbitai
Copy link

coderabbitai bot commented May 20, 2024

Important

Auto Review Skipped

Auto reviews are disabled on this repository.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

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.

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 a review. This is useful when automatic reviews are disabled for the repository.
  • @coderabbitai resolve resolve all the CodeRabbit review comments.
  • @coderabbitai help to get help.

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

CodeRabbit Configration 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.

@JssDWt
Copy link
Contributor Author

JssDWt commented May 20, 2024

I'm not entirely sure how to test. Ideally I'd like to run an integration test where 2 nodes have a channel open. Then stop one of the nodes, delete the edge from the database and run the node again. getchaninfo should fail. Then run the node again with the new flag. getchaninfo should then succeed.

Not sure how to access the node's database in the test though, with all the different backends available.

yyforyongyu
yyforyongyu reviewed May 21, 2024
View reviewed changes
Copy link
Collaborator

@yyforyongyu yyforyongyu left a comment

Choose a reason for hiding this comment

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

Do we know the root cause of this issue, like why it's missing in the first place?

config.go
// RepopulateMissingEdges is a value indicating whether missing edges of
// local channels should be re-added to the local view of the graph on
// startup.
RepopulateMissingEdges bool `long:"repopulate-missing-edges" description:"Repopulates any missing edges of local channels in the node's local view of the graph. This can help with 'edge not found' issues where LND will always select the default routing policy. Should be set to false after successful execution to avoid repopulating on every restart of lnd."`
Copy link
Collaborator

Choose a reason for hiding this comment

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

This looks more like a db migration for the affected nodes than a config to me.

Copy link
Contributor Author

Choose a reason for hiding this comment

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

If the problem was permanently fixed in #7613 that could be a better solution. What do you think @ellemouton? Was the 'edge not found' issue reliably fixed by that PR?

@JssDWt
Copy link
Contributor Author

JssDWt commented May 21, 2024

Do we know the root cause of this issue, like why it's missing in the first place?

It happens mostly on zero conf private channels. Also at least one public channel on our node is affected. I don't know what causes this. I assume it has to do with a peer disconnect during the initial channel setup process.

@JssDWt
Copy link
Contributor Author

JssDWt commented May 23, 2024

Another option is to add the missing edge in the default case here if the edge was not updated, but the channel exists, what do you think @yyforyongyu?

@lightninglabs-deploy
Copy link

@JssDWt, remember to re-request review from reviewers when ready

@JssDWt
Copy link
Contributor Author

JssDWt commented Jun 2, 2024

There's a few ways to go with this PR

  1. Make it a database migration
    a. The question is whether a single database migration is enough. I'm not sure whether (actually I suspect that it isn't) the underlying issue is fixed in funding: use default forwarding policy if persisted values not found聽#7613. If it turns out to be not enough, I don't think this is the way to go.
  2. Make a different PR that inserts a missing edge if it's not found when trying to updatechanpolicy to set a fee. That way you'll be able to fix missing edges manually by calling updatechanpolicy. This seems like a fine solution to me.
  3. Leave it as-is. Seems like a fine solution to me too.

Please provide some guidance on what I should do.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers

@yyforyongyu yyforyongyu yyforyongyu left review comments

At least 2 approving reviews are required to merge this pull request.

Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

Successfully merging this pull request may close these issues.

[bug]: "edge not found" for local channel
3 participants
@JssDWt @lightninglabs-deploy @yyforyongyu