Azure - Configure disaster RECOVERY and automatic failover for Azure Cosmos DB?

We have our Azure Cosmos DB provisioned in East US and our hot-stand by region is West US.

I know that Cosmos DB supports Geo-Replication with multi master.

How do I configure the Azure Cosmos DB to support the disaster recovery with automatic fail over? Would it impact the connection string?

Please see this article for the complete information: https://learn.microsoft.com/azure/cosmos-db/troubleshoot-sdk-availability

If your account has multiple regions, the Cosmos DB SDKs already apply retry mechanism when they detect regional outages. You can define the preference in order of this failover retries by creating the client specifying the regional preference. Depending on your SDK language and version, this could be:

• The ConnectionPolicy.PreferredLocations property in .NET V2 SDK.
• The CosmosClientOptions.ApplicationRegion or CosmosClientOptions.ApplicationPreferredRegions properties in .NET V3 SDK.
• The CosmosClientBuilder.preferredRegions method in Java V4 SDK.
• The CosmosClient.preferred_locations parameter in Python SDK.
• The CosmosClientOptions.ConnectionPolicy.preferredLocations parameter in JS SDK.

This preference configuration also determines which regions you want to read/write from in a normal (no regional outage situation).