This project adds some metadata collections in the users databases. These collections will be cleaned up if user commits migration properly, otherwise user will need to manually clean up these collections.

Summary

Support Conflict Resolution during Sharded Cluster Replication due to concurrent document movement between source shards

Motivation

As in the proposed architecture for Cluster to Cluster Replication, when the source cluster is a sharded cluster, we would want to establish per-shard change streams via the source mongos(es). And if we want to increase parallelism and apply change events from different shards concurrently, we may get out-of-order (conflict) change events if a document is moved between shards (e.g. by a chunk migration). This project is to implement the solution identified in PM-2416 on top of REP-32 to handle such out-of-order (conflict) change events and support sharded clusters for C2C Replication with concurrent document movement between source shards.

Cast of Characters

• Product Owner: Alan Zheng
• Project Lead: Wenbin Zhu
• Program Manager: Elizabeth Roytburd

Documentation

Product Description
Scope Document
Technical Design Document