Amazon DocumentDB (with MongoDB compatibility) adds sixteen additional Amazon CloudWatch metrics for monitoring MongoDB opcounters, connections, cursors, operations on documents and index cache hits
Amazon DocumentDB (with MongoDB compatibility) is a fast, scalable, highly available, and fully managed document database service that supports MongoDB workloads. Amazon DocumentDB makes it easy and intuitive to store, query, and index JSON data. Starting today, Amazon DocumentDB offers sixteen additional in Amazon CloudWatch.
Source:: Amazon AWS