[release/7.0] Fix batching boundary with cycle breaking #29388
Merged
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Fixes #29356
Description
In 7.0, we added a perf optimization where our topological sort identifies special graph edges which require a batching boundary (e.g. between adding a principal with a database-generated ID and a dependent). However, in certain cases where there's a cycle in the graph and we perform cycle breaking, the batching boundary wasn't respected, and both commands were sent together in the same batch, causing an error.
Customer impact
Certain update patterns which have worked before now produce an exception.
How found
Customer reported on 7.0 RC.
Regression
Yes, in 7.0 (unreleased).
Testing
Added a test.
Risk
Low, minimal simple change.