Hi All, AFAIK the "X-Request-Id" header is not well-defined. I could not find any docs about it in RFCs or W3C publications, but Wikipedia [1] lists it as "non-standard" both in requests and responses and "superseded" by "traceparent" in requests.
My preference is option (2): no "X-Request-Id" header in responses. I'm also ok with options (1), but I believe it would be valuable to cover that functionality with a feature flag, which is "off" by default. This is to avoid making the impression that the "X-Request-Id" header is promoted by Polaris as the main method for request correlation. From the overall project's perspective, I believe we should align with and support OTel standards for observability / request correlation. [1] https://en.wikipedia.org/wiki/List_of_HTTP_header_fields Cheers, Dmitri. On Fri, Oct 31, 2025 at 8:17 AM Alexandre Dutra <[email protected]> wrote: > Hi all, > > This thread follows up on [1] to discuss whether we should echo the > client-generated X-Request-Id header in the response. > > Before Quarkus, the situation was unclear: Polaris on Dropwizard [2] > did not seem to echo the header, but Dropwizard itself has a > RequestIdFilter that does [3]. > > We have two options: > > 1) Echo the X-Request-Id header. > - Pros: Allows clients to correlate requests and responses. > - Cons: risk of over-engineering since we don't have users asking for > this. > > 2) Do not echo the X-Request-Id header. > - Pros: No action required on the Polaris side. > - Cons: None apparent. > > I don't have a strong opinion, but I slightly favor option 1 to > accommodate those who strongly value this feature. > > Thoughts? > > Thanks, > Alex > > [1] https://lists.apache.org/thread/bb1qyxjt827t3tomv2xp0s1kovxjsp94 > [2] > https://github.com/apache/polaris/blob/4b18ec065ff16f74b11bc85fdc6ea9036eca7274/dropwizard/service/src/main/java/org/apache/polaris/service/dropwizard/PolarisApplication.java#L516 > [3] > https://github.com/dropwizard/dropwizard/blob/3833f0e1d9fb8cae256fe09379733b8d651f8b87/dropwizard-jersey/src/main/java/io/dropwizard/jersey/filter/RequestIdFilter.java#L42-L49 >
