When migrating retryable CRUD op session entries, we generate a prePostImage oplog entry if necessary.
Later in the process, we filter out these CRUD op entries, but not their corresponding prePostImageOplog entries. We skip the latter because the prePostImage oplog entries are created as no-ops.
We should also filter out corresponding prePostImage oplog entries.
We currently have two types of no-op entries that will come through the session catalog migration pipeline. These are either sentinel oplog entries or prePostImage oplog entries. We should:
- Automatically let sentinel oplog entries pass through, and
- Check the pre- or postImage in prePostImage oplog entries to filter based on a mismatched shard key.