sarama: fix span name and add payload size sem conv

[srikanthccv]

Updates the span name to follow messaging semantic conventions and adds message payload size attribute

[codecov[bot]]

Codecov Report

Merging #2594 (3ae7063) into main (ace6b3c) will increase coverage by 0.0%. The diff coverage is 87.5%.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #2594   +/-   ##
=====================================
  Coverage   74.4%   74.4%           
=====================================
  Files        145     145           
  Lines       6685    6707   +22     
=====================================
+ Hits        4974    4993   +19     
- Misses      1564    1566    +2     
- Partials     147     148    +1     

Impacted Files	Coverage Δ
...n/github.com/Shopify/sarama/otelsarama/producer.go	93.7% <86.9%> (-1.0%)	:arrow_down:
...github.com/Shopify/sarama/otelsarama/dispatcher.go	100.0% <100.0%> (ø)

[dmathieu]

You mention you're updating the span name to follow semantic conventions. Is there a spec specifying those conventions for kafka, or examples of other libraries using the new name?

[srikanthccv]

Is there a spec specifying those conventions for kafka, or examples of other libraries using the new name?

I didn't lookup other libraries. There is no spec specifying those conventions for kafka or (any specific message system).

[dmathieu]

I'm not sure I understand how this is an update to "follow messaging semantic conventions" if no other libraries is doing the same thing, and no conventions are defined?

[srikanthccv]

if no other libraries is doing the same thing

There is more likely chance other instrumentations are also not following the semconv so I didn't bother looking at them.

and no conventions are defined?

I am not sure if they are going to add naming conventions for every messaging system. There is a general guideline which says span name should <destination (topic)> <operation name>. More here.

[srikanthccv]

I think this has enough approvals and comments are addressed @open-telemetry/go-instrumentaiton-maintainers Can someone merge this?

[srikanthccv]

Can this be merged so that It will be part of the next release? I would like to use this feature.