AWS customers can now expand their DocumentDB reach across multiple regions around the world.
AWS is introducing a new multi-region capability that they call “Global Clusters.” DocumentDB, like most AWS databases, has always supported multiple read replicas across different availability zones within a region. AWS is extending that capability across regions with their Global Clusters solution.
In other words, while there is still a single primary instance for writes, the Global Clusters feature will support read-only secondary instances in up to five remote regions.
Why is this important? Well, AWS has already identified two core use cases for the new Global Clusters feature. The first is disaster recovery. The Global Clusters will ensure that the database stays live in the event of a regional outage. The second use case is one of performance. The clusters will deliver low-latency reads across different local regions across the world.
The benefits of globe-straddling instances with high speed system operations
Karthik Vijayraghavan, AWS’s Senior Solutions Architect, confirmed the new advantages of Global Clusters feature in a blog post. “With the launch of global clusters, Amazon DocumentDB now enables you to deploy a cluster that spans across multiple AWS Regions,” he explains. “Global clusters replicate your data to clusters in up to five Regions with little to no impact on performance. Global clusters provide faster recovery from Region-wide outages and enable low-latency global reads.”
In addition to these two main use cases, Vijayraghavan outlines some ancillary benefits of the Global Cluster feature. For example, the new feature offers “scalable secondary clusters”. The number and type of instances in the primary and secondary clusters don’t need to be the same. Users can create secondary clusters with one replica instance and scale up to 16 instances as needed. Scaling instances in Amazon DocumentDB takes less than 10 minutes, regardless of the data volume.
In addition, the platform offers high-speed replication across clusters. Global clusters use fast, storage-based physical replication of data from the primary Region to secondary clusters in other Regions. The compute instances provisioned in primary and secondary Regions don’t participate in replication, which frees them up for serving application requests.