My preference is to continue returning the x-request-id response header. Istio/Envoy and other service proxies include the x-request-id in logs, meaning that if users have a request id to report, we can more easily diagnose issues by tracing through the LB and service logs. Some of our users are including traceparent headers, but IME most clients don't have OTEL set up in their data applications.
Mike On Fri, Oct 31, 2025 at 9:08 AM Dmitri Bourlatchkov <[email protected]> wrote: > 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 "non-standard" both in requests and responses and "superseded" by 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 > > >
