cadonna commented on code in PR #12638:
URL: https://github.com/apache/kafka/pull/12638#discussion_r971709124
##########
streams/src/main/java/org/apache/kafka/streams/processor/internals/ProcessorStateManager.java:
##########
@@ -209,7 +212,9 @@ void registerStateStores(final List<StateStore> allStores,
final InternalProcess
processorContext.uninitialize();
for (final StateStore store : allStores) {
if (stores.containsKey(store.name())) {
- maybeRegisterStoreWithChangelogReader(store.name());
+ if (!stateUpdaterEnabled) {
+ maybeRegisterStoreWithChangelogReader(store.name());
Review Comment:
That is indeed confusing! When a task is recycled, the changelogs of the
task to recycle are unregistered from the changelog reader. Then a new task is
created and the state manager of the task to recycle is moved to the new task.
For example, when a standby task is recycled to become an active task, its
changelogs are unregistered from the changelog reader
(https://github.com/apache/kafka/blob/2b2039f0ba88e210dd09031291c050cfcda7ce4a/streams/src/main/java/org/apache/kafka/streams/processor/internals/ProcessorStateManager.java#L579),
a new active task is created, and the state manager of the standby task is
transferred to the new active task
(https://github.com/apache/kafka/blob/2b2039f0ba88e210dd09031291c050cfcda7ce4a/streams/src/main/java/org/apache/kafka/streams/processor/internals/ActiveTaskCreator.java#L218).
After the recycling, the new active task is in state `CREATED` and owns a
state manager that has all state stores registered, but has the changelogs
unregistered in the
changelog reader. When the new active task is initialized, Streams tries to
register the state stores again. That is when it reaches this code and it will
execute the `if`-branch. That is the state store is registered but the
changelogs aren't registered with the changelog reader.
--
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]
