Add debug logging for deduplicated queries

routing/providerquerymanager/providerquerymanager.go

@@ -193,10 +193,6 @@ func (pqm *ProviderQueryManager) FindProvidersAsync(sessionCtx context.Context,
 		close(ch)
 		span.End()
 		return ch
-	case <-sessionCtx.Done():
-		ch := make(chan peer.AddrInfo)
-		close(ch)
-		return ch
 	}
 
 	// DO NOT select on sessionCtx. We only want to abort here if we're
@@ -486,6 +482,13 @@ func (npqm *newProvideQueryMessage) handle(pqm *ProviderQueryManager) {
 		span.AddEvent("NewQuery", trace.WithAttributes(attribute.Stringer("cid", npqm.k)))
 		ctx = trace.ContextWithSpan(ctx, span)
 
+		// Use context derived from pqm.ctx here, and not the context from the
+		// request (npqm.ctx), because this inProgressRequestStatus applies to
+		// all in-progress requests for the CID (npqm.k).
+		//
+		// For tracing, this means that only the span from the first
+		// request-in-progress for a CID is used, even if there are multiple
+		// requests for the same CID.
 		requestStatus = &inProgressRequestStatus{
 			listeners: make(map[chan peer.AddrInfo]struct{}),
 			ctx:       ctx,
@@ -504,6 +507,7 @@ func (npqm *newProvideQueryMessage) handle(pqm *ProviderQueryManager) {
 		}
 	} else {
 		trace.SpanFromContext(npqm.ctx).AddEvent("JoinQuery", trace.WithAttributes(attribute.Stringer("cid", npqm.k)))
+		log.Debugf("Joined existing query for cid %s which now has %d queries in progress", npqm.k, len(requestStatus.listeners)+1)
 	}
 	inProgressChan := make(chan peer.AddrInfo)
 	requestStatus.listeners[inProgressChan] = struct{}{}