Reusability of DnsNameResolver

[ceremo]

Hi,

I have a question regarding gRPC's internal implementation of DnsNameResolver (io.grpc.internal). Netty also provides its own DnsNameResolver (io.netty.resolver.dns), and according to the changelog (netty/netty@netty-4.1.113.Final...netty-4.1.114.Final), recent versions seem to be actively improving it. The question is why do you need to define your own implementation of DnsNameResolver?

Thanks for your time.

[ejona86]

Those name resolvers are completely different APIs. gRPC's DnsNameResolver mostly leverages libc's getaddrinfo; it's an adapter to gRPC's NameResolver/LoadBalancer infrastructure. Netty's DnsNameResolver is a full DNS client implementation.

We've considered having gRPC's DnsNameResolver use Netty's DnsNameResolver, but there's some technical details and we don't gain too much for typical gRPC workloads.