[hotfix][cdc-connector][mongodb] Fix unstable test cases for snapshot…

… back-filling (apache#3506)
qiaozongmi · Sep 23, 2024 · 096be8f · 096be8f
1 parent 54228b8
commit 096be8f
Showing 1 changed file with 9 additions and 0 deletions.
diff --git a/...test/java/org/apache/flink/cdc/connectors/mongodb/source/MongoDBParallelSourceITCase.java b/...test/java/org/apache/flink/cdc/connectors/mongodb/source/MongoDBParallelSourceITCase.java
@@ -468,6 +468,15 @@ private List<String> testBackfillWhenWritingEvents(
                     mongoCollection.updateOne(
                             Filters.eq("cid", 2000L), Updates.set("address", "Pittsburgh"));
                     mongoCollection.deleteOne(Filters.eq("cid", 1019L));
+
+                    // Rarely happens, but if there's no operation or heartbeat events between
+                    // watermark #a (the ChangeStream opLog caused by the last event in this hook)
+                    // and watermark #b (the calculated high watermark that limits the bounded
+                    // back-filling stream fetch task), the last event of hook will be missed since
+                    // back-filling task reads between [loW, hiW) (high watermark not included).
+                    // Workaround: insert a dummy event in another collection to forcefully push
+                    // opLog forward.
+                    database.getCollection("customers_1").insertOne(new Document());
                 };
 
         switch (hookType) {