all: remove Trace and SpanContext from SearchOptions

Since the move to gRPC these fields should make no difference.
SpanContext is never set anymore by our clients. Trace is still set, but
I believe we should be communicating to trace or not via grpc.

Additionally we just rely on the opentracing global tracer. If tracing
is not configured it will just use the noop tracer, not sure why we had
our own implementation.

Test Plan: go test. Will seek more guidance on other tests to run.

api.go

@@ -951,15 +951,8 @@ type SearchOptions struct {
 	// When enabled, all other scoring signals are ignored, including document ranks.
 	UseKeywordScoring bool
 
-	// Trace turns on opentracing for this request if true and if the Jaeger address was provided as
-	// a command-line flag
-	Trace bool
-
 	// If set, the search results will contain debug information for scoring.
 	DebugScore bool
-
-	// SpanContext is the opentracing span context, if it exists, from the zoekt client
-	SpanContext map[string]string
 }
 
 // String returns a succinct representation of the options. This is meant for
@@ -1016,13 +1009,8 @@ func (s *SearchOptions) String() string {
 	addBool("ChunkMatches", s.ChunkMatches)
 	addBool("UseDocumentRanks", s.UseDocumentRanks)
 	addBool("UseKeywordScoring", s.UseKeywordScoring)
-	addBool("Trace", s.Trace)
 	addBool("DebugScore", s.DebugScore)
 
-	for k, v := range s.SpanContext {
-		add("SpanContext."+k, strconv.Quote(v))
-	}
-
 	b.WriteByte('}')
 	return b.String()
 }

api_proto.go

@@ -698,7 +698,6 @@ func SearchOptionsFromProto(p *proto.SearchOptions) *SearchOptions {
 		ChunkMatches:           p.GetChunkMatches(),
 		UseDocumentRanks:       p.GetUseDocumentRanks(),
 		DocumentRanksWeight:    p.GetDocumentRanksWeight(),
-		Trace:                  p.GetTrace(),
 		DebugScore:             p.GetDebugScore(),
 		UseKeywordScoring:      p.GetUseKeywordScoring(),
 	}
@@ -723,7 +722,6 @@ func (s *SearchOptions) ToProto() *proto.SearchOptions {
 		ChunkMatches:           s.ChunkMatches,
 		UseDocumentRanks:       s.UseDocumentRanks,
 		DocumentRanksWeight:    s.DocumentRanksWeight,
-		Trace:                  s.Trace,
 		DebugScore:             s.DebugScore,
 		UseKeywordScoring:      s.UseKeywordScoring,
 	}

api_proto_test.go

@@ -334,9 +334,6 @@ func TestProtoRoundtrip(t *testing.T) {
 
 	t.Run("SearchOptions", func(t *testing.T) {
 		f := func(f1 *SearchOptions) bool {
-			if f1 != nil {
-				f1.SpanContext = nil
-			}
 			p1 := f1.ToProto()
 			f2 := SearchOptionsFromProto(p1)
 			if diff := cmp.Diff(f1, f2); diff != "" {

cmd/zoekt-webserver/main.go

@@ -293,10 +293,7 @@ func main() {
 	}
 
 	logger := sglog.Scoped("ZoektWebserverGRPCServer")
-
-	streamer := web.NewTraceAwareSearcher(s.Searcher)
-	grpcServer := newGRPCServer(logger, streamer)
-
+	grpcServer := newGRPCServer(logger, s.Searcher)
 	handler = multiplexGRPC(grpcServer, handler)
 
 	srv := &http.Server{
@@ -638,7 +635,7 @@ func traceContext(ctx context.Context) sglog.TraceContext {
 	return sglog.TraceContext{}
 }
 
-func newGRPCServer(logger sglog.Logger, streamer zoekt.Streamer, additionalOpts ...grpc.ServerOption) *grpc.Server {
+func newGRPCServer(logger sglog.Logger, streamer zoekt.Streamer) *grpc.Server {
 	metrics := mustGetServerMetrics()
 
 	opts := []grpc.ServerOption{
@@ -656,8 +653,6 @@ func newGRPCServer(logger sglog.Logger, streamer zoekt.Streamer, additionalOpts
 		),
 	}
 
-	opts = append(opts, additionalOpts...)
-
 	// Ensure that the message size options are set last, so they override any other
 	// server-specific options that tweak the message size.
 	//

grpc/protos/zoekt/webserver/v1/webserver.proto

@@ -44,6 +44,9 @@ message StreamSearchResponse {
 }
 
 message SearchOptions {
+  reserved 13;
+  reserved "trace";
+
   // Return an upper-bound estimate of eligible documents in
   // stats.ShardFilesConsidered.
   bool estimate_doc_count = 1;
@@ -100,10 +103,6 @@ message SearchOptions {
   // will be used. This option is temporary and is only exposed for testing/ tuning purposes.
   double document_ranks_weight = 12;
 
-  // Trace turns on opentracing for this request if true and if the Jaeger address was provided as
-  // a command-line flag
-  bool trace = 13;
-
   // If set, the search results will contain debug information for scoring.
   bool debug_score = 14;
 

trace/trace.go

@@ -25,13 +25,13 @@ type Tracer struct {
 }
 
 func New(ctx context.Context, family, title string) (*Trace, context.Context) {
-	tr := Tracer{Tracer: GetOpenTracer(ctx, nil)}
+	tr := Tracer{Tracer: opentracing.GlobalTracer()}
 	return tr.New(ctx, family, title)
 }
 
 // New returns a new Trace with the specified family and title.
 func (t Tracer) New(ctx context.Context, family, title string) (*Trace, context.Context) {
-	span, ctx := StartSpanFromContextWithTracer(
+	span, ctx := opentracing.StartSpanFromContextWithTracer(
 		ctx,
 		t.Tracer,
 		family,

web/server.go

@@ -174,7 +174,7 @@ func NewMux(s *Server) (*http.ServeMux, error) {
 		mux.HandleFunc("/print", s.servePrint)
 	}
 	if s.RPC {
-		mux.Handle("/api/", http.StripPrefix("/api", zjson.JSONServer(traceAwareSearcher{s.Searcher})))
+		mux.Handle("/api/", http.StripPrefix("/api", zjson.JSONServer(s.Searcher)))
 	}
 
 	mux.HandleFunc("/healthz", s.serveHealthz)