Amazon DocumentDB is a managed MongoDB-compatible database service provided by AWS. It provides the database in clusters, with multiple instances, for high-availablity. To help with cost-reduction strategies, AWS allows DocumentDB clusters to be stopped and restarted. While the cluster is stopped, you’re not charged. So it’s a great candidate to shut off overnight and on weekends if it’s not needed.

In December, AWS announced the new VPC Reachability Analyzer tool. Using this tool, AWS can analyse the paths within your VPC to determine whether the various components in your VPC can communicate with each other or not.