application: syncfs on storage during startup #10495
Closed
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
If Redpanda crashes during storage writes, there may be non-persistent metadata left visible in the filesystem. To provide the guarantee that everything the storage layer sees on disk during recovery is persistent, call syncfs during startup. The strength of this guarantee depends on the underlying filesystem, as some filesystems may lie about persistence if there has previously been an I/O error on a device, by marking pages clean even though they were not successfully flushed. This does not help in all cases, but it is a cheap thing to do that may help us reason about storage consistency issues across crash/restart cycles if they are seen in the field.
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Outdated suggestions cannot be applied.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.
This depends on:
If Redpanda crashes during storage writes, there
may be non-persistent metadata left visible in
the filesystem.
To provide the guarantee that everything the storage layer sees on disk during recovery is persistent,
call syncfs during startup.
The strength of this guarantee depends on the underlying filesystem, as some filesystems may lie about persistence if there has previously been an I/O error on a device, by marking pages clean even though they were not
successfully flushed.
This does not help in all cases, but it is a cheap thing to do that may help us reason about storage
consistency issues across crash/restart cycles if
they are seen in the field.
Backports Required
Release Notes