From: Pieter Lexis <pieter.lexis@powerdns.com>
Date: Tue, 14 Oct 2025 11:12:02 +0000 (+0200)
Subject: fix(dnsdist): make the rootspan the parent of processResponse
X-Git-Tag: rec-5.4.0-alpha1~187^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f5d26f9bab90fdbfbe84d826c976684369e354e8;p=thirdparty%2Fpdns.git

fix(dnsdist): make the rootspan the parent of processResponse
---

diff --git a/pdns/dnsdistdist/dnsdist-opentelemetry.cc b/pdns/dnsdistdist/dnsdist-opentelemetry.cc
index 60c64ac2d0..ab1185c9f2 100644
--- a/pdns/dnsdistdist/dnsdist-opentelemetry.cc
+++ b/pdns/dnsdistdist/dnsdist-opentelemetry.cc
@@ -215,6 +215,21 @@ void Tracer::setSpanAttribute([[maybe_unused]] const SpanID& spanid, [[maybe_unu
 #endif
 }
 
+SpanID Tracer::getRootSpanID()
+{
+#ifdef DISABLE_PROTOBUF
+  return 0;
+#else
+  if (auto spans = d_preActivationSpans.read_only_lock(); spans->size() != 0) {
+    auto iter = std::find_if(spans->cbegin(), spans->cend(), [](const auto& span) { return span.parent_span_id == pdns::trace::s_emptySpanID; });
+    if (iter != spans->cend()) {
+      return iter->span_id;
+    }
+  }
+  return SpanID{};
+#endif
+}
+
 SpanID Tracer::getLastSpanID()
 {
 #ifdef DISABLE_PROTOBUF
diff --git a/pdns/dnsdistdist/dnsdist-opentelemetry.hh b/pdns/dnsdistdist/dnsdist-opentelemetry.hh
index aa3de14ed8..f3d5d27292 100644
--- a/pdns/dnsdistdist/dnsdist-opentelemetry.hh
+++ b/pdns/dnsdistdist/dnsdist-opentelemetry.hh
@@ -145,6 +145,13 @@ public:
    */
   void closeSpan(const SpanID& spanID);
 
+  /**
+   * @brief Get the top-most SpanID
+   *
+   * @return The SpanID of the root Span
+   */
+  [[nodiscard]] SpanID getRootSpanID();
+
   /**
    * @brief Get the last SpanID generated
    *
diff --git a/pdns/dnsdistdist/dnsdist.cc b/pdns/dnsdistdist/dnsdist.cc
index c424d7e0a8..4cfc5ebec3 100644
--- a/pdns/dnsdistdist/dnsdist.cc
+++ b/pdns/dnsdistdist/dnsdist.cc
@@ -591,7 +591,7 @@ bool processResponse(PacketBuffer& response, DNSResponse& dnsResponse, bool mute
 {
   pdns::trace::dnsdist::Tracer::Closer closer;
   if (auto tracer = dnsResponse.ids.getTracer(); tracer != nullptr && dnsResponse.ids.tracingEnabled) {
-    closer = tracer->openSpan("processResponse");
+    closer = tracer->openSpan("processResponse", tracer->getRootSpanID());
   }
 
   const auto& chains = dnsdist::configuration::getCurrentRuntimeConfiguration().d_ruleChains;