Overall it seems minimal changes are required but I was thinking if there could be an opportunity to evolve the API within Undertow 2 making migration to 3 easier in the future.

One example being on SSSessionInfo we make use of the following method: -

void renegotiate(HttpServerExchange exchange, SslClientAuthMode sslClientAuthMode) throws IOException;

which has now been changed to: -

void renegotiate(HttpServerExchange exchange, ClientAuth sslClientAuthMode) throws IOException;

The first form is making use of Xnio API and the second is using Netty API.

If this was deprecated in Undertow 2 and a pure Undertow variant added it could be usable both in 2 and 3.

I suspect a number of the other changes breaking API compatibility could be handled in a similar way.

Regards,

Darran Lofthouse.