merlimat opened a new pull request, #25687:
URL: https://github.com/apache/pulsar/pull/25687
## Summary
Replace the TODO in `DagWatchClient.connectionClosed()` that left long-lived
producers / consumers stranded on a stale layout after a transient broker
disconnect. The DAG watch is the consumer / producer's only path to learning
about split / merge events; without reconnect, a single network blip silently
drops the client off future layout updates and never surfaces an error to the
application.
The new logic mirrors the proven pattern used by `ScalableTopicsWatcher`
(namespace-watcher session) and `ScalableConsumerClient` (controller session):
- `start()` (initial create) keeps its current behavior — the future is
failed on disconnect so `producer.create()` / `consumer.subscribe()` fails fast
when the broker is unreachable.
- After the initial layout has arrived, `connectionClosed()` schedules a
reconnect with exponential backoff (100 ms → 30 s). The reconnect path calls
`getConnection` again, re-registers the same `sessionId` on the fresh
`ClientCnx`, and re-issues `ScalableTopicLookup`; the broker re-pushes the
current layout via `onUpdate`, which resets the backoff.
- The connect / reconnect logic is shared in a single `attach(cnx)` method
so both paths use identical wiring.
Adds a `forceCloseConnectionForTesting()` hook (mirroring the one on
`ScalableConsumerClient`) for cross-module integration tests.
## Test plan
- [x] `V5DagWatchAutoReconnectTest` (3 integration tests):
- Producer's DAG channel force-closed mid-life — sends after the close
still succeed.
- Consumer's DAG channel force-closed mid-life — receives after the close
still succeed.
- Reflective check that the `cnx` field on `DagWatchClient` gets
re-populated within the backoff window.
- [x] Full V5 broker test suite green (128/128).
- [x] `pulsar-client-v5` and `pulsar-broker` checkstyle clean.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
