Performance tuning and maintaining DocumentDB

DocumentDB is a very specialized database, so tuning methods that are used on other systems are not that effective. It is important to choose the right size instance for your DocumentDB as this controls the resources it is given. Without sufficient memory and CPU, your performance will be poor and queries will be slow. If you are migrating from MongoDB, it is recommended to match the resource that was allocated to your MongoDB cluster initially as a start and tune from there. For a new workload, it can be different to accurately estimate the resources needed. For those cases, you need to test different instance sizes as extensively as possible before launching your production or critical workloads.

Once your primary instance has been sized correctly, you can consider some other performance tuning options such as read replicas.

Read replicas

DocumentDB allows for up to 15 read replicas per cluster. A read replica is a copy of...