[#4643] AggregateBasedJpaEventStorageEngine#stream loops until StreamingCondition matching events are retrieved#4684
Merged
Merged
Conversation
Adjust the AggregateBasedJpaEventStorageEngine#streaming to keep querying events until some match the given StreamingCondition. If we don't do this, there's a chance that the batch is empty, stalling the ContinuesMessageStream until a new event is appended. Thus, essentially blocking a consumer like the PooledStreamingEventProcessor, potentially indefinitely. #4625
smcvb
requested review from
MateuszNaKodach,
jangalinski and
laura-devriendt-lemon
and removed request for
a team
smcvb
added
Type: Bug
smcvb
changed the title
AggregateBasedJpaEventStorageEngine#stream loops until StreamingCondition matching events are retrievedAggregateBasedJpaEventStorageEngine#stream loops until StreamingCondition matching events are retrieved
Contributor
|
Tested the same way as #4681 — confirms it works !.
|
hatzlj
approved these changes
Jun 23, 2026
hatzlj
left a comment
hatzlj
left a comment
Contributor
There was a problem hiding this comment.
I have one suggestion to improve the readability, otherwise looks good to me
Contributor
|
would be worth to run the |
Contributor
Author
Will do! |
Simplify loop by using a do-while i.o. while(true) #4643
hjohn
approved these changes
Jun 23, 2026
Contributor
Author
Validated the new test to work for the |
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
4 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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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 adjusts the
AggregateBasedJpaEventStorageEngine#streamingmethod, to keep querying batches of events until some match the givenStreamingCondition.If we don't do this, there's a chance that the batch is empty, stalling the
ContinuousMessageStreamuntil it's nudged (e.g. when a new event is appended).Thus, the old approach essentially blocks a consumer like the
PooledStreamingEventProcessor, potentially indefinitely.This PR is a second try to resolve issue #4643, with the original PR being #4681.
This PR differs from #4681 as it's an
AggregateBasedJpaEventStorageEngineonly solution.This is by design, as Axon Server and our PostgreSQL
EventStorageEngineimplementations ensure the same: they loop through the event store until aStreamingConditionmatch is found.As all
EventStorageEnginessupport this, and should support this, a test has been added to theStorageEngineBackedEventStoreTestSuiteto validate the behavior that anEventStorageEngine#streamoperation will progress until a firstStreamingConditionmatch has been found.By doing the above, this PR works towards resolving #4643.
A port to
axon-5.1.xis still required, though.