The RESP server today may or may not be configured to have OCTET stream for the key media type. All keys used with RESP will always be OCTET based, there is no reason to have a different storage medium.

Taken from Zulip https://infinispan.zulipchat.com/#narrow/stream/118645-infinispan/topic/RESP/near/377348043

Okay, so in that case RESP server will always require its cache to have OCTET stream for the key type and throw an error if the cache is defined and doesn't have that? I am leaning towards that myself as we can avoid all encoding/decoding for key and is very explicit (no magic).

The two "magic" things would be

1. No defined cache we set it to OCTET
2. No defined cache but a default, we set it to OCTET if media type is not defined and error if it is (telling user to define the cache)

We need to make sure the DataConversion converts to the DEFAULT_KEY instance so it uses the IdentityEncoder as well in core.