BMM Restart Improvements Part 2. Followers claim their tokens after handling stop assignments#921
Merged
jzakaryan merged 14 commits intolinkedin:masterfrom Jan 23, 2023
Merged
Conversation
vmaheshw
reviewed
Dec 19, 2022
Collaborator
vmaheshw
left a comment
There was a problem hiding this comment.
Brooklin does not maintain the latest datastream cache and does not listen to incremental updates. So, this PR may not work. Please recheck if your tests contains multiple instances and the follower only instance is able to claim the token.
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Outdated
Show resolved
Hide resolved
vmaheshw
reviewed
Jan 13, 2023
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Outdated
Show resolved
Hide resolved
datastream-server/src/main/java/com/linkedin/datastream/server/zk/ZkAdapter.java
Show resolved
Hide resolved
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Show resolved
Hide resolved
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Show resolved
Hide resolved
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Show resolved
Hide resolved
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Show resolved
Hide resolved
vmaheshw
reviewed
Jan 13, 2023
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Outdated
Show resolved
Hide resolved
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Show resolved
Hide resolved
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Show resolved
Hide resolved
jzakaryan
commented
Jan 18, 2023
...connector/src/main/java/com/linkedin/datastream/connectors/kafka/AbstractKafkaConnector.java
Show resolved
Hide resolved
jzakaryan
commented
Jan 18, 2023
...connector/src/main/java/com/linkedin/datastream/connectors/kafka/AbstractKafkaConnector.java
Show resolved
Hide resolved
Collaborator
shrinandthakkar
left a comment
There was a problem hiding this comment.
The overall code flow LGTM, just a couple of comments.
datastream-server/src/main/java/com/linkedin/datastream/server/zk/ZkAdapter.java
Outdated
Show resolved
Hide resolved
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Show resolved
Hide resolved
shrinandthakkar
previously approved these changes
Jan 20, 2023
vmaheshw
reviewed
Jan 23, 2023
datastream-server-api/src/main/java/com/linkedin/datastream/server/api/connector/Connector.java
Outdated
Show resolved
Hide resolved
datastream-server-restli/src/test/java/com/linkedin/datastream/server/TestCoordinator.java
Show resolved
Hide resolved
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Outdated
Show resolved
Hide resolved
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Show resolved
Hide resolved
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Show resolved
Hide resolved
vmaheshw
reviewed
Jan 23, 2023
datastream-server/src/main/java/com/linkedin/datastream/server/Coordinator.java
Outdated
Show resolved
Hide resolved
jzakaryan
commented
Jan 23, 2023
|
|
||
| // Shutdown executor services | ||
| if (_scheduledExecutor != null) { | ||
| _scheduledExecutor.shutdown(); |
Collaborator
Author
There was a problem hiding this comment.
I'm calling the more graceful shutdown path here. No new submissions will be accepted but the tasks that have already been submitted will be lingering until completion. I could block and wait for all tasks to complete here. I could also force terminate everything (which is a best effort operation). I don't think more oppressive measures are required here.
vmaheshw
approved these changes
Jan 23, 2023
shrinandthakkar
approved these changes
Jan 23, 2023
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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 pull request is part of a series of changes that are meant to improve BMM Restart and make it easier to debug restart failures and trace them to the faulty hosts. Part 2 includes changes to the follower's code to make them claim assignment tokens for the datastreams that have been successfully stopped. It also includes the following improvements that were suggested in #919:
AssignmentTokenclass was made immutable thanks to @ehoner pointing out the JSON library APIs.The PRs in this series deal with the following aspects:
Part 1 – Introduction of assignment tokens and support for issuing tokens by the leader coordinator (#919)
Part 2 – Changes to the followers' handleAssignmentChange to make them claim the tokens issued by the leader.
Part 3 – Changes to the leader to make it poll the ZooKeeper and wait for the assignment change (stop) to be propagated and executed by the cluster. This will also include code for handling assignment failures and signals to the client that problem(s) occurred in the form of log messages and a new metric.
Part 4 – This one will deal with edge cases and cleanup. More specifically, what happens when a leader fails over during an assignment (assignment token nodes are persistent and their lifecycle is tied to that of the parent datastream).