We have dedicated M10 cluster created before 10/16/2020 using Azure provider. Just tried setting up private endpoint and status shows Available but not able to connect through Azure Private Link.
As per documentation there is an important note
Some Atlas clusters on Azure created before 10/16/2020 use Azure networking hardware that is incompatible with Azure Private Link. You can still configure Azure Private Link for Atlas projects with these clusters to use with supported clusters in the project, but you will not be able to connect to the incompatible ones through Azure Private Link.
All new Atlas clusters are compatible with Azure Private Link. If you must connect to your cluster using only Azure Private Link, you can create a new cluster in the same Atlas project and migrate your data.
I confirmed this is the issue by creating a new cluster and able to connect using Azure private link.
Documentation suggests we create a new cluster and do a live migration of data. This will setup a mirror cluster which we can later switch following cutover plan.
However for us this is not easy as we have lots of live apps which will suffer from downtime as we will have to stop the apps, update the connection string and start again.
Is there any other way to deal with this. Some other trick which can force changing azure network interface hardware compatible with private link. How about scaling M10 to higher tier?