feat(storagenode): add an upper limit of log stream replicas count in a storage node #294
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
hungryjang
approved these changes
Dec 27, 2022
… a storage node This patch adds a new CLI flag, `--max-logstream-replicas-count,` which limits the number of log stream replicas in a storage node. The default value is -1, meaning no upper limit, and a storage node cannot create a log stream replica if it is zero. A storage node keeps a count variable for the number of log stream replicas. Whenever the storage node creates a new replica, it checks if the number of log stream replicas exceeds the upper limit. If there is no problem, the storage node creates a new replica and increases the count variable. Conversely, the storage node decreases the count variable whenever a log stream replica is removed. This approach has a limitation: it cannot distinguish between standard and garbage replicas. Fundamentally, a storage node has no method to distinguish them. So, this PR won't consider that. Resolves kakao#293
ijsong
force-pushed
the
limits-lsreplica
branch
from
1fe0f1f to
2cfc8bf
Compare
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Outdated suggestions cannot be applied.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.
What this PR does
This patch adds a new CLI flag,
--max-logstream-replicas-count,which limits the number of logstream replicas in a storage node. The default value is -1, meaning no upper limit, and a storage
node cannot create a log stream replica if it is zero.
A storage node keeps a count variable for the number of log stream replicas. Whenever the storage
node creates a new replica, it checks if the number of log stream replicas exceeds the upper limit.
If there is no problem, the storage node creates a new replica and increases the count variable.
Conversely, the storage node decreases the count variable whenever a log stream replica is removed.
This approach has a limitation: it cannot distinguish between standard and garbage replicas.
Fundamentally, a storage node has no method to distinguish them. So, this PR won't consider that.
Which issue(s) this PR resolves
Resolves #293