Request

SERVER-124149 discusses using $collStats to determine whether a cluster is DSC or ASC. This approach, though, requires specific privileges on a specific collection. Thus mongosync had to expand its set of required privs in DOCSP-62567, which is undesirable from a security perspective.

It would be better—and consistent with unsharded DSC clusters—for `serverStatus` to indicate DSC vs. ASC. This way the query for the cluster's storage type is properly scoped to the cluster write-large rather than a specific collection. (It also doesn't bake in an assumption that all namespaces are stored the same way.)

And/or, better yet …

Add a DSC/ASC indicator to the `hello` response. This way each and every client could learn this fundamental detail about the cluster without extra permissions.