Service Config, RPC retry policy, load balancing and custom name resolution in v1.x

[maniak-dobrii]

What are you trying to achieve?

For grpc-swift 1.x (or v1, can use 1.24.1, the latest at the moment for reference)

1. Is there a way to apply GRPCChannel configuration based on Service Config?

   • An RPC (vs connection) retry policy, load balancing etc.

2. Is there a load balancing and custom name resolution implementation? Maybe, available as a separate package?

What have you tried so far?

Based on my understanding after reading the documentation, examples and (shallow) investigating v1 and v2 code, all the implementations in question are only available in v2 and not in v1:

• a Service Config based configuration (via CallOptions and ServiceConfig etc.),
• load balancing (via PickFirstLoadBalancer etc.),
• and custom name resolution (via NameResolver etc.) implementations.

The only options to achieve Service Config configuration in v1 are:

• a custom implementation,
  • e.g. a retry policy custom client interceptor implementation,
  • or a custom GRPCChannel implementation,
• using pre-release grpc-swift v2.

Thank you.

Code examples

While creating the channel via ClientConnection:

let channel = ClientConnection
    ...
    .connect(host: host, port: port)

or a GRPCChannelPool:

let channel = try GRPCChannelPool.with(
    target: .host(host, port: port)
    ...
)