Add Tracing in SqlClient

SqlClient doesn’t have any tracing in .Net Core. All the Bid Tracing API calls were removed during the port to Core. One of the options is to use EventSource to emit traces during runtime. Something similar was done by @stephentoub in System.Data.Common . Ref: https://github.com/dotnet/corefx/blob/master/src/System.Data.Common/src/System/Data/Common/DataCommonEventSource.cs

cc @corivera

[cheenamalhotra]

Closing issue since EventSource tracing is now added to SqlClient.

[roji]

It does seem that both styles of tracing may be relevant, although it also seems that there is considerable overlap in what they provide, and I personally still don’t have a 100% clear picture of which should be used for what.

Regardless, what would be really great is some sort of quick spec/writeup on which events you’re planning to emit and when, before implementation. That would allow us to have a more concrete conversation about it possibly align across different ADO providers.

Note: in addition to https://github.com/dotnet/corefx/issues/21160, https://github.com/dotnet/corefx/issues/29534 is an additional issue I filed at the time. tl;dr SqlCient’s current implementation of DiagnosticSource seems like it doesn’t really follow best practices. I understand that the priority here is to bring over what exists from Core to Framework and not to change things, but this could also be a good moment to rethink the DiagnosticSource support itself. If you’re willing to do this, I’d be happy to work together and produce a spec.