Building Disaster Recovery Solution on MongoDB Atlas Clusters

Disaster recovery solutions are critical for ensuring the continuity and resilience of data in any modern database system, including MongoDB Atlas clusters. These solutions mitigate the potential impact of catastrophic events like natural disasters, hardware failures, or human errors that lead to data loss or service interruptions.

MongoDB Atlas is a managed cloud database service that offers robust disaster recovery capabilities to safeguard valuable data. One key feature of MongoDB Atlas is the ability to create regular backups of the entire cluster. These backups capture the state of the data at a specific time, enabling organizations to restore their databases to a known state in the event of data corruption or accidental deletion.

Business Scenario:

In this blog, I will explain the configurations and testing challenges of the Disaster recovery solution of MongoDB atlas clusters hosted on Azure. Disaster recovery configuration is straightforward by selecting desired regions but testing the solution along with applications\microservices running on Azure is a complex process. Some additional configurations should be done to keep the Disaster recovery solution in working condition to meet audit and business requirements.

Business Challenges:

You may encounter below challenges while testing disaster recovery solutions:

There needs to be more documentation on network connectivity among MongoDB Atlas replicas across the regions and Azure.
We may need help because a few regions from Atlas have similar public IPs to use in connectivity establishment. In that case, we need to choose different regions for our configuration.
While choosing regions\locations need to consider specific compliance requirements or data sovereignty concerns, data residency, privacy laws, and regulatory audits ensuring that disaster recovery configurations comply with relevant regulations can be challenging.
Ensuring robust and low-latency network connectivity between the primary and secondary environments can be challenging, especially when dealing with different geographic regions.

Solution Strategy:

Choose the right application connection string from the MongoDB atlas connections wizard.
The selection of the connection string must be made based on the application stack we use to develop the application.
Please choose the appropriate application drivers and keep them up-to-date.
If the connection is established between Azure and Mongo Atlas with V-net peering, please do the V-net peering for each Azure atlas region replica independently and test the connection.
If the connection is established with an endpoint between Azure and Mongo Atlas, an endpoint must be created for each replica region in Atlas with Azure resource details.
Use Mongo CMD shell or Mongo Compass to check whether the connecting string works correctly after V-net peering to each region.
Check the connectivity with individual replica connection strings and cluster-aware connection strings from the application-hosted system \service etc.
Use a standard connection developed for multi-region replicas (cluster aware) instead of a single replica connection string.
Conduct thorough testing of failover and failback scenarios to ensure the resilience of disaster recovery configuration. Trigger a failover from the primary region to a secondary region and validate that the application functions correctly. Test the process of failing back to the primary region once it is restored.
Continuously monitor the replication lag between regions, cluster health, and backup status. Set up alerts to proactively identify any issues.
Additionally, configure read and write preferences to optimize data access and distribution. For example, we can configure read preference to allow reads from secondary regions to distribute the workload, improve performance, and separate replicas for Analytics purposes.