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https://issues.apache.org/jira/browse/CAMEL-25025?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18119982#comment-18119982
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Andrea Cosentino commented on CAMEL-25025:
------------------------------------------
PR opened: https://github.com/apache/camel/pull/26961
Both fixes in one PR, a commit each, since they touch the same consumer threads.
----
_Claude Code on behalf of oscerd (Andrea Cosentino)._
> camel-mongodb - a change stream event with a non-ObjectId _id loops the
> consumer forever
> ----------------------------------------------------------------------------------------
>
> Key: CAMEL-25025
> URL: https://issues.apache.org/jira/browse/CAMEL-25025
> Project: Camel
> Issue Type: Bug
> Components: camel-mongodb
> Reporter: Andrea Cosentino
> Assignee: Andrea Cosentino
> Priority: Major
>
> h3. Summary
> A change stream event whose {{_id}} is not an {{ObjectId}} - a string, an int
> or a compound key, all
> ordinary in MongoDB - makes the consumer fail on that event, regenerate its
> cursor from the same resume
> token, read the same event again and fail again, once per
> {{cursorRegenerationDelay}} for as long as the
> route runs.
> h3. Details
> {{MongoDbChangeStreamsThread.doRun()}}:
> {code:java}
> ObjectId documentId = dbObj.getDocumentKey().getObjectId(MONGO_ID).getValue();
> {code}
> Verified against {{bson-5.9.2}} and {{mongodb-driver-core-5.9.2}}:
> * {{BsonDocument.getObjectId(key)}} is {{throwIfKeyAbsent(key);
> get(key).asObjectId();}}, so it throws
> {{BsonInvalidOperationException}} when {{_id}} is absent or is not an
> {{ObjectId}}.
> * {{BsonInvalidOperationException extends BSONException extends
> RuntimeException}}, while
> {{MongoException extends RuntimeException}} - they are siblings, so the
> enclosing
> {{catch (MongoException e)}} in {{doRun()}} does not catch it.
> * {{ChangeStreamDocument.getDocumentKey()}} is annotated {{@Nullable}} (as
> are {{getFullDocument()}},
> {{getResumeToken()}} and {{getOperationType()}}), so events without a
> document key - {{invalidate}},
> {{drop}}, {{rename}}, {{dropDatabase}} - throw a {{NullPointerException}}
> on the same line.
> Either exception reaches {{MongoAbstractConsumerThread.run()}}, which logs
> it, closes the cursor,
> regenerates it and continues. Because the failure happens *before* the
> exchange is created, the resume
> token is never advanced, so the regenerated cursor resumes at the same event
> and the cycle repeats
> indefinitely at {{cursorRegenerationDelay}} (default 1000 ms).
> h3. Relation to CAMEL-16025
> CAMEL-16025 reported the {{NullPointerException}} on this line when the
> watched collection is dropped and
> was fixed in 3.10.0 by hardening {{MongoAbstractConsumerThread.run()}} so the
> thread survives and the
> cursor is regenerated. That addressed thread death, which was the reported
> symptom. This issue is the
> half that remains: for a *valid, resumable* event - a document with a string
> {{_id}} - the consumer now
> survives but can never make progress past it.
> h3. Also worth fixing here
> The hardening from CAMEL-16025 logs the stack trace only on the branch where
> the thread is stopping:
> {code:java}
> if (keepRunning) {
> log.warn("... Will try again on next poll.", e.getMessage());
> } else {
> log.warn("... ConsumerThread will be stopped.", e.getMessage(), e);
> }
> {code}
> The recurring-failure branch - the one that fires once a second in the loop
> above - gets no stack trace,
> which makes this hard to diagnose from a log. The two branches should be the
> other way round, or both
> should carry the exception.
> h3. Proposed fix
> Read the document key defensively: skip the header rather than throw when
> {{getDocumentKey()}} is null or
> {{_id}} is not an {{ObjectId}}, so that the event still reaches the route and
> the resume token can
> advance. Keep the {{CamelMongoDbObjectId}} header for the {{ObjectId}} case
> so existing routes are
> unaffected.
> ----
> _Reported by Claude Code on behalf of oscerd (Andrea Cosentino)._
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