Don't lock log_visit table to check if privilege is granted #15247
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Outdated suggestions cannot be applied.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.
Instead use a table we write to less frequently. Otherwise, whenever we over privacy settings or when it is trying to delete unused actions it will lock the log_visit table for a short time that could cause random tracking issues (eg heap of requests piling up trying to write to the log_visit table).
It's only a read lock but according to MySQL it still blocks other sessions from writing
from http://www.mysqltutorial.org/mysql-table-locking/:
This method is rarely executed so I don't think it was any big issue and it should be quickly unlocked again.