1a) OPES processors MUST support chunked transfer coding
when handling data send by an OCP server.
IMO Yes. chunked is a good thing.
IMO no for now.
While chunked coding is a good thing for HTTP to get low latency and
persistency for data that's length is not known a priori, chunked coding is not
needed for OCP because it encapsulated data in DUM messages with size parameter
which is the same functionality as chunked encoding (and more).
If there is a HTTP/1.0 proxy for which you want to write an OCP client (e.g.
Squid), why adding chunked encoding, if it is not needed? It cannot be
forwarded to the client (unless you want to update Squid to support HTTP/1.1 at
the same time ;-), and so needs to be removed again.
I think from all the discussion with header correctness and OPES processor's
responsibility here, it is better to not add any transfer encoding by the
callout service. It is better if only the OPES processor does this for now. And
transferring DUM messages into chunked encoding for HTTP is very simple.
Regards
Martin