I’ve been wanting to update my Redis shard for the past few years to use the RESP3 format, which adds new data types and changes the output format of some existing commands. Details are in this issue. I originally kept it on RESP2 because, at the time, nothing was using RESP3. Even the modules owned by Redis Labs (now just called Redis, Inc) were still outputting RESP2 data types.
The downside is that it’s a pretty breaking change, which is difficult for something like Redis where most applications aren’t using it directly and are instead using it through shards like cable and mosquito. Both of those shards do dependency management well and would avoid this breaking change until they were ready to upgrade, but others might not.
Anyway, if anyone’s willing to take a look and offer feedback, that would be helpful.