Don't normalize headers with "hyphen -> underscore" #3104
+256 −266
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I think this can be considered a breaking change, and I'm not sure how it affects other services, but it fixes the behavior according to the OTel specification.
Changes
-to_on the HTTP header normalizer.Details
The current behavior is incorrect according to the HTTP RFCs regarding HTTP headers (because they are just case-insensitive), and the OpenTelemetry specification itself.
The following headers are not the same:
But those two, should be treated as same: