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https://issues.apache.org/jira/browse/CAMEL-25545?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Claus Ibsen updated CAMEL-25545:
--------------------------------
Fix Version/s: 4.24.0
> camel-pgevent - the consumer reconnects only after the first lost connection;
> after the next one it stays disconnected without an error while the route
> keeps running
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: CAMEL-25545
> URL: https://issues.apache.org/jira/browse/CAMEL-25545
> Project: Camel
> Issue Type: Bug
> Components: camel-pgevent
> Reporter: shashank
> Assignee: shashank
> Priority: Major
> Fix For: 4.24.0
>
>
> {{PgEventConsumer.doInit}} (line 72 at main 9432ba16d026) creates one
> {{BackgroundTask}} for reconnecting, and {{PgEventListener.reconnect()}}
> (line 103), which the driver calls through {{closed()}} when the connection
> is lost, runs that same task every time:
> {code:java}
> if (!reconnectTask.isRunning()) {
> reconnectTask.run(endpoint.getCamelContext(), () -> {
> ...
> initConnection(); // new connection, LISTEN, notification listener
> ...
> return true;
> });
> }
> {code}
> A {{BackgroundTask}} completes only once. Its latch ({{new
> CountDownLatch(1)}}) is counted down by the first successful attempt; after
> that {{run()}} schedules an attempt with the initial delay of one second,
> {{waitForTaskCompletion}} returns at once because the latch is already 0 and
> cancels the attempt, and {{runTaskWrapper}} would do nothing anyway ("the
> task is done and every further run is a no-op"). The other users of the task
> API (camel-master, camel-sjms, camel-kafka) build a new task for each use.
> So the consumer reconnects after the first connection loss, and after the
> second one {{reconnect()}} returns without connecting: the consumer no longer
> listens to the channel, no notification is routed any more, nothing is logged
> after the "Connection to PostgreSQL lost unexpected. Re-connecting..."
> warning, and the route still shows as started. Only a restart of the route
> (which runs {{doInit}} again) repairs it. A database that restarts or fails
> over twice during the lifetime of the route is enough.
> h3. Reproduction
> New {{PgEventConsumerReconnectTest}} (no database: a mocked {{DataSource}}
> hands out mocked {{PGConnection}}s through the {{datasource}} option; the
> test calls {{closed()}} on the listener as the driver does, and the call
> returns when the reconnect is done). On main, twice:
> {noformat}
> PgEventConsumerReconnectTest.reconnectsAfterEveryConnectionLoss: The consumer
> must reconnect after the second connection loss ==> expected: <3> but was: <2>
> {noformat}
> h3. Proposed fix
> {{reconnect()}} creates a new {{BackgroundTask}} (same pool, name and budget
> as before) for each reconnect, and keeps it in the (now volatile) field for
> the "already running" check. With the fix the test also verifies that the
> third connection executed {{LISTEN testchannel}} and got the notification
> listener. No upgrade guide note: nothing changes for a consumer that has not
> lost its connection twice. camel-pgevent with the fix: 1 unit test (the new
> one; the module had none), 0 failures; the integration tests need a
> PostgreSQL container (Docker) and were not run. Test dependency added:
> mockito-junit-jupiter.
> Not changed here: a consumer that is stopped while a reconnect is waiting
> leaves the thread that called {{closed()}} waiting on the task (the pool is
> shut down, the task is not cancelled); that needs its own look.
> Found by reading how the task API is used across components, with a small
> TLA+ model of the reconnect (connection lost, attempt, return of {{run()}},
> the latch of the task): "when reconnect() has returned the consumer listens
> to the channel" holds for one connection loss and is violated for two (6
> states); with a new task per reconnect it holds for two and three losses.
> Confirmed with the real consumer.
> Affected: main, camel-4.22.x, camel-4.18.x, camel-4.14.x (same reconnect code
> and the same single-use latch in {{BackgroundTask}}, GitHub contents API).
> Duplicate check (2026-10-11): JIRA text "pgevent" since 2021 (10: CAMEL-22146
> added the reconnect, CAMEL-22949 and CAMEL-23646 changed the task callback,
> none about a second connection loss); GitHub open pull requests for
> camel-pgevent: none. No open pull request changes {{PgEventConsumer}}.
> _Filed with Claude Code on behalf of allthingssecurity._
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