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https://issues.apache.org/jira/browse/CAMEL-25024?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18119981#comment-18119981
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Andrea Cosentino commented on CAMEL-25024:
------------------------------------------
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 - the consumers discard a failed exchange and advance past it
> ---------------------------------------------------------------------------
>
> Key: CAMEL-25024
> URL: https://issues.apache.org/jira/browse/CAMEL-25024
> Project: Camel
> Issue Type: Bug
> Components: camel-mongodb
> Reporter: Andrea Cosentino
> Assignee: Andrea Cosentino
> Priority: Major
>
> h3. Summary
> Both MongoDB consumers swallow a route failure without a trace and then move
> their position past the
> message that failed, so the exchange is lost and nothing records it.
> h3. Details
> {{MongoDbChangeStreamsThread.doRun()}}:
> {code:java}
> try {
> consumer.getProcessor().process(exchange);
> this.resumeToken = currentResumeToken;
> commitManager.recordResumeToken(currentResumeToken);
> commitManager.commit();
> } catch (Exception ignored) {
> }
> {code}
> {{MongoDbTailingThread.doRun()}}:
> {code:java}
> try {
> consumer.getProcessor().process(exchange);
> } catch (Exception e) {
> // do nothing
> }
> tailTracking.setLastVal(dbObj);
> {code}
> Neither calls {{getExceptionHandler()}}, so {{bridgeErrorHandler}} has no
> effect on these consumers and a
> route failure produces no log output whatsoever - the empty catch discards
> the exception entirely.
> The position advances regardless:
> * *Change streams*: the failed event's resume token is not committed, but the
> next event that succeeds
> commits its own, so the persisted position steps over the failure. The
> event is skipped permanently and
> silently.
> * *Tailable cursor*: {{tailTracking.setLastVal(dbObj)}} sits outside the try,
> so it runs even when
> processing threw. With {{persistentTailTracking=true}} the record is
> skipped across restarts too.
> h3. History
> The empty catch predates the visible git history: it is already present in
> the 2019-08-14 commit that
> renamed {{camel-mongodb3}} to {{camel-mongodb}}, and no issue has touched it
> since. It does not look like
> a considered decision, and nothing documents the at-most-once behaviour it
> produces.
> h3. Proposed fix
> Hand the failure to {{getExceptionHandler()}} in both consumers, as other
> Camel consumers do, so that it
> is logged and {{bridgeErrorHandler}} works. Move {{setLastVal}} inside the
> success path of the tailable
> consumer so a failed record is not marked as consumed. Whether a failure
> should also stop the position
> from advancing in the change-streams consumer is a behaviour change worth an
> upgrade-guide note.
> ----
> _Reported by Claude Code on behalf of oscerd (Andrea Cosentino)._
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