Adding new region to an existing cluster without down time

Hi,

We are trying to add new regions to our existing MongoDB Atlas clusters. Currently we have 3 nodes in AWS us-east-1 region. We are planning to update it to 2 nodes in us-east-1, 2 nodes in us-west-2 and 1 node in us-east-2.

Is it possible to do that without any down time? We tried doing this in one of our test clusters and there was some down time. We are getting com.mongodb.MongoSocketWriteException in our spring boot applications running inside a Kubernetes cluster. These apps restarted several times during the process.

Is this because of some misconfigurations our side? or this is expected during adding new region?

And this happens only if we reduce the number of nodes from us-east-1 region (i.e. 2-2-1 configuration). Other configurations like 3-3-1, 3-2-2, etc are working without any issues. But we want 2-2-1.

Any advice and suggestions will be greatly appreciated.

Thank You

Hi @nidhinradh ,

Adding or removing nodes should not cause downtime.

There might be elections happening, but your application and drivers should be capable in withstanding it

Check out our guide for building resilient application with atlas :

If the issue persists I suggest to contact support for further investigation.

Thanks
Pavel

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