Switching dedicated cluster to flex clusters

Fahd_Wahab · 2025-02-09T09:55:04.748Z

I’m currently right sizing some of my mongo instances and one issue I ran into was our connections. When using dedicated clusters for our project, the connection would work outright. In our network access we have a security group configured.

When I switched to a flex server, these same servers cannot connect. I also have a VPC configured and I imagine the vpc connection is working to get my dedicated clusters to connect. Is it possible to use security groups to connect my flex server?

Anurag_Kadasne · 2025-02-26T17:53:30.748Z

Fahd_Wahab:

I’m currently right sizing some of my mongo instances and one issue I ran into was our connections. When using dedicated clusters for our project, the connection would work outright. In our network access we have a security group configured.

Hi Fahd

Apologies about the delay here. Flex clusters do not have private networking or VPC peering. Therefore you would have to connect to them using the cluster’s public endpoint.

HARSHIT_SINGH2 · 2025-03-08T04:50:29.573Z

Hey Anurag! Since the new flex clusters are marketed as new product combining features from shared clusters and serverless clusters, and the depricated serverless clusters have a support for Private endpoints. But Flex seems to lack it. Is there any chance, in near future, MongoDB will rollout private networking or vpc peering for flex clusters? Or We’ve to shift to dedicated ones.

Anurag_Kadasne · 2025-03-09T13:06:37.435Z

Hi Harshit

Currently there are no plans to support Private Endpoints for Flex clusters before the migration deadlines for Serverless. Therefore, you will have to migrate to Dedicated clusters if you currently have a Serverless cluster and want to continue using Private Endpoints.

Vivek_Chavda · 2025-06-11T23:27:06.315Z

Hi Anurag,
currently i am on flex tier and it has storage limitation if i upgrade to dedicated will it affect anything in my application connection or anything.

Anurag_Kadasne · 2025-06-12T15:12:58.612Z

Hi Vivek, no it will not. There will be a small amount of downtime when you upgrade (a few minutes, you should see this estimate on the screen before you finalize the upgrade)