- Provide AppendToOutgoingContext interface for imrproved performance
over manually creating md and joining with existing md
- Add benchmarks for old/new approaches
Fixes#1390
This will prevent the incoming RPCs' metadata from appearing in outgoing RPCs
unless it is explicitly copied, e.g.:
incomingMD, ok := metadata.FromContext(ctx)
if ok {
ctx = metadata.NewContext(ctx, incomingMD)
}
Fixes#1148