Mechanism to detect the region from where request is served

[kirankumarkolli]

Is your feature request related to a problem? Please describe.
Mechanism to detect the region from where request is served

Describe the solution you'd like
*Response types expose a way to know the region which served the request.
Queries which are served from multiple regions also needs to be covered.

Describe alternatives you've considered
Currently this information is not available.

Additional context
NA

[bchong95]

@kirankumarkolli and @j82w This information is already in the PointOperationDiagnostics right?

[j82w]

It does have contacted regions, but it's not just the region. Is this good enough or do we need an explicit region name field?

For example:
URL from data explorer:
https://myAccountTemp.documents.azure.com:443/

String from diagnostics:
{https://myAccountTemp-eastus2.documents.azure.com/}

[kirankumarkolli]

Explicit will make it quite useful if it needs programmatic logic.
For queries, should it be a collection of regions?

[j82w]

This only works for direct + TCP mode where the client side request diagnostics exists. There is a PR adding the clients side request statistics to the query diagnostics which will return each page as a JSON object with the query metrics, client side request statistics, and some other info required for debugging.

[j82w]

#2312