[C++][FlightRPC] Benchmark in-process Flight performance

[asfimport]

It can be convenient to use Flight to abstract over communication within a process and between two processes. We should add this case to the benchmark to start. UCX has an in-process loopback transport (UCX_TLS=self), and ARROW-15282 will enable implementing a specialized transport if more performance is desired (e.g. possibly based on the C Data Interface).

Reporter: David Li / @lidavidm

Related issues:

• [C++][FlightRPC] Implement a UCX transport (is related to)

_{Note: This issue was originally created as ARROW-15756. Please see the migration documentation for further details.}

[asfimport]

David Li / @lidavidm:
I couldn't get this to work. I wonder if UCX_TLS=self only works if both sides share a worker as well (which would be a little unfortunate).

[asfimport]

Todd Farmer / @toddfarmer:
This issue was last updated over 90 days ago, which may be an indication it is no longer being actively worked. To better reflect the current state, the issue is being unassigned. Please feel free to re-take assignment of the issue if it is being actively worked, or if you plan to start that work soon.