Allow tags in UDP v0 protocol about plog

[nelgau]

I like it. Each listener still has a default (at least via the global default) and you can optionally emit to a different topic. 👍

[pcarrier]

@nelgau rewrote the RFC. Care to review?

[nelgau]

Seems reasonable to me! 👍

[pcarrier]

Turned into an enhancement.

[pcarrier]

Added bullet point, "Tags from the last processed fragment win; well-behaving clients only set tags on the last fragment to avoid reducing the chunk size or increasing packet count." as discussed with @nelgau.

[nelgau]

I agree with this last bullet point. A correctly-implemented producer should emit consistent headers—whether that means each fragment contains identical tags or, more likely, that only the final message has tags. In both cases, the behavior should be correct.

[pcarrier]

Going with \0-separated, specified UTF-8 and Collection<String> instead. I can be convinced it's a bad idea.