in flink-connector-mongodb/src/main/java/org/apache/flink/connector/mongodb/source/enumerator/assigner/MongoScanSplitAssigner.java [112:121]
public void addSplitsBack(Collection<MongoSourceSplit> splits) {
for (MongoSourceSplit split : splits) {
if (split instanceof MongoScanSourceSplit) {
remainingScanSplits.add((MongoScanSourceSplit) split);
// we should remove the add-backed splits from the assigned list,
// because they are failed
assignedScanSplits.remove(split.splitId());
}
}
}