pg-replication-slot fix: if PG connection got lost while trying to send (#3389)
the status to PG, the reconnect logic will never be called and the
exchange will be reprocessed forever.
Explanation:
After we receive the payload from PostgreSQL, we keep it in memory so we
can process it again and again in case the processing of the exchange
fails. After the successful completion of the exchange, we (1) send the
status to PostgreSQL, (2) reset the payload, and (3) we receive the next
one.
If for some reason we lose the connection while trying to do step 2, the
payload will never get reset, and it will be processed forever. We need
to reset the payload first so in case of failure in updating the status,
the next poll will reconnect and receive the next payload. The next
status update cover both payload as LSNs are sequential.
diff --git a/components/camel-pg-replication-slot/src/main/java/org/apache/camel/component/pg/replication/slot/PgReplicationSlotConsumer.java b/components/camel-pg-replication-slot/src/main/java/org/apache/camel/component/pg/replication/slot/PgReplicationSlotConsumer.java
index 5073f97..4390ae4 100644
--- a/components/camel-pg-replication-slot/src/main/java/org/apache/camel/component/pg/replication/slot/PgReplicationSlotConsumer.java
+++ b/components/camel-pg-replication-slot/src/main/java/org/apache/camel/component/pg/replication/slot/PgReplicationSlotConsumer.java
@@ -157,6 +157,10 @@
private void processCommit(Exchange exchange) {
try {
+ // Reset the `payload` buffer first because it's already processed, and in case of losing the connection
+ // while updating the status, the next poll will try to reconnect again instead of processing the stale payload.
+ this.payload = null;
+
PGReplicationStream stream = getStream();
if (stream == null) {
@@ -166,8 +170,6 @@
stream.setAppliedLSN(stream.getLastReceiveLSN());
stream.setFlushedLSN(stream.getLastReceiveLSN());
stream.forceUpdateStatus();
-
- this.payload = null;
} catch (SQLException e) {
getExceptionHandler().handleException("Exception while sending feedback to PostgreSQL.", exchange, e);
}
