provider: buffer pin providers #10746
Open
+231
−12
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Fixes #10596. The reproviding process can take long. Currently, each CID to be provided is obtained by making a query to the pinner and reading one by one as the CIDs get provided. While this query is ongoing, the pinner holds a Read mutex on the pinset. If a pin-add-request arrives, a goroutine will start waiting for a Write mutex on the pinset. From that point, no new Read mutexes can be taken until the writer can proceed and finishes. However, no one can proceed because the read mutex is still held while the reproviding is ongoing. The fix is mostly in Boxo, where we add a "buffered" provider which reads the cids onto memory so that they can be provided at its own pace without making everyone wait. The consequence is we will need more RAM memory. Rule of thumb is 1GiB extra per 20M cids to be reprovided.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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 #10596.
The reproviding process can take long. Currently, each CID to be provided is
obtained by making a query to the pinner and reading one by one as the CIDs
get provided.
While this query is ongoing, the pinner holds a Read mutex on the pinset.
If a pin-add-request arrives, a goroutine will start waiting for a Write mutex
on the pinset. From that point, no new Read mutexes can be taken until the writer
can proceed and finishes.
However, no one can proceed because the read mutex is still held while the
reproviding is ongoing.
The fix is mostly in Boxo, where we add a "buffered" provider which reads the
cids onto memory so that they can be provided at its own pace without making
everyone wait.
The consequence is we will need more RAM memory. Rule of thumb is 1GiB extra per 20M cids to be reprovided.