From cde6d45ca51672653524d94e70e73eed8450a3f0 Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Wed, 11 Aug 2021 12:18:17 +0200
Subject: [PATCH 01/14] traces: suport for opentelemetry

---
 cmd/revad/runtime/runtime.go                  | 106 +++++++++++-------
 go.mod                                        |   8 +-
 go.sum                                        |  19 ++++
 internal/grpc/interceptors/appctx/appctx.go   |   9 +-
 internal/grpc/interceptors/auth/auth.go       |  14 ---
 .../grpc/services/gateway/storageprovider.go  |   8 +-
 internal/http/interceptors/appctx/appctx.go   |   9 +-
 .../http/services/owncloud/ocdav/delete.go    |  17 +--
 .../http/services/owncloud/ocdav/propfind.go  |  10 +-
 pkg/publicshare/manager/json/json.go          |   7 --
 pkg/rgrpc/rgrpc.go                            |  11 +-
 pkg/rgrpc/status/status.go                    |  22 ++--
 pkg/rgrpc/todo/pool/pool.go                   |  18 ++-
 pkg/rhttp/rhttp.go                            |  14 ++-
 pkg/trace/trace.go                            |  33 ++++++
 15 files changed, 196 insertions(+), 109 deletions(-)
 create mode 100644 pkg/trace/trace.go

diff --git a/cmd/revad/runtime/runtime.go b/cmd/revad/runtime/runtime.go
index b1e918b102..0d27376075 100644
--- a/cmd/revad/runtime/runtime.go
+++ b/cmd/revad/runtime/runtime.go
@@ -28,16 +28,15 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/cs3org/reva/pkg/registry/memory"
-
-	"github.com/cs3org/reva/pkg/utils"
-
 	"contrib.go.opencensus.io/exporter/jaeger"
 	"github.com/cs3org/reva/cmd/revad/internal/grace"
 	"github.com/cs3org/reva/pkg/logger"
+	"github.com/cs3org/reva/pkg/registry/memory"
 	"github.com/cs3org/reva/pkg/rgrpc"
 	"github.com/cs3org/reva/pkg/rhttp"
 	"github.com/cs3org/reva/pkg/sharedconf"
+	rtrace "github.com/cs3org/reva/pkg/trace"
+	"github.com/cs3org/reva/pkg/utils"
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
 	"github.com/rs/zerolog"
@@ -47,6 +46,11 @@ import (
 	"go.opencensus.io/trace"
 )
 
+const (
+	tracingOC = "opencensus"
+	tracingOT = "opentelemetry"
+)
+
 // Run runs a reva server with the given config file and pid file.
 func Run(mainConf map[string]interface{}, pidFile, logLevel string) {
 	logConf := parseLogConfOrDie(mainConf["log"], logLevel)
@@ -84,6 +88,9 @@ type coreConf struct {
 	TracingEndpoint    string `mapstructure:"tracing_endpoint"`
 	TracingCollector   string `mapstructure:"tracing_collector"`
 	TracingServiceName string `mapstructure:"tracing_service_name"`
+
+	// TracingService specifies the service. i.e OpenCensus, OpenTelemetry, OpenTracing...
+	TracingService string `mapstructure:"tracing_service"`
 }
 
 func run(mainConf map[string]interface{}, coreConf *coreConf, logger *zerolog.Logger, filename string) {
@@ -91,7 +98,9 @@ func run(mainConf map[string]interface{}, coreConf *coreConf, logger *zerolog.Lo
 	logger.Info().Msgf("host info: %s", host)
 
 	// initRegistry()
-	initTracing(coreConf, logger)
+	if coreConf.TracingEnabled {
+		initTracing(coreConf, logger)
+	}
 	initCPUCount(coreConf, logger)
 
 	servers := initServers(mainConf, logger)
@@ -144,7 +153,6 @@ func initServers(mainConf map[string]interface{}, log *zerolog.Logger) map[strin
 	}
 
 	if len(servers) == 0 {
-		// nothing to do
 		log.Info().Msg("nothing to do, no grpc/http enabled_services declared in config")
 		os.Exit(1)
 	}
@@ -152,12 +160,54 @@ func initServers(mainConf map[string]interface{}, log *zerolog.Logger) map[strin
 }
 
 func initTracing(conf *coreConf, log *zerolog.Logger) {
-	if err := setupOpenCensus(conf); err != nil {
-		log.Error().Err(err).Msg("error configuring open census stats and tracing")
+	switch {
+	case conf.TracingService == tracingOC:
+		err := setupOpenCensus(conf)
+		if err != nil {
+			log.Error().Err(err).Msg("error configuring open census stats and tracing")
+			os.Exit(1)
+		}
+	case conf.TracingService == tracingOT:
+		rtrace.SetTraceProvider(conf.TracingCollector)
+	default:
+		log.Error().Msg(fmt.Sprintf("error configuring telemetry. unknown type `%s`", conf.TracingService))
 		os.Exit(1)
 	}
 }
 
+func setupOpenCensus(conf *coreConf) error {
+	if err := view.Register(ochttp.DefaultServerViews...); err != nil {
+		return err
+	}
+
+	if err := view.Register(ocgrpc.DefaultServerViews...); err != nil {
+		return err
+	}
+
+	if !conf.TracingEnabled {
+		return nil
+	}
+
+	if conf.TracingServiceName == "" {
+		conf.TracingServiceName = "revad"
+	}
+
+	je, err := jaeger.NewExporter(jaeger.Options{
+		AgentEndpoint:     conf.TracingEndpoint,
+		CollectorEndpoint: conf.TracingCollector,
+		ServiceName:       conf.TracingServiceName,
+	})
+
+	if err != nil {
+		return err
+	}
+
+	// register it as a trace exporter
+	trace.RegisterExporter(je)
+	trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()})
+	return nil
+}
+
 func initCPUCount(conf *coreConf, log *zerolog.Logger) {
 	ncpus, err := adjustCPU(conf.MaxCPUs)
 	if err != nil {
@@ -270,39 +320,6 @@ func getHTTPServer(conf interface{}, l *zerolog.Logger) (*rhttp.Server, error) {
 	return s, nil
 }
 
-func setupOpenCensus(conf *coreConf) error {
-	if err := view.Register(ochttp.DefaultServerViews...); err != nil {
-		return err
-	}
-
-	if err := view.Register(ocgrpc.DefaultServerViews...); err != nil {
-		return err
-	}
-
-	if !conf.TracingEnabled {
-		return nil
-	}
-
-	if conf.TracingServiceName == "" {
-		conf.TracingServiceName = "revad"
-	}
-
-	je, err := jaeger.NewExporter(jaeger.Options{
-		AgentEndpoint:     conf.TracingEndpoint,
-		CollectorEndpoint: conf.TracingCollector,
-		ServiceName:       conf.TracingServiceName,
-	})
-
-	if err != nil {
-		return err
-	}
-
-	// register it as a trace exporter
-	trace.RegisterExporter(je)
-	trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()})
-	return nil
-}
-
 //  adjustCPU parses string cpu and sets GOMAXPROCS
 // according to its value. It accepts either
 // a number (e.g. 3) or a percent (e.g. 50%).
@@ -349,6 +366,13 @@ func parseCoreConfOrDie(v interface{}) *coreConf {
 		fmt.Fprintf(os.Stderr, "error decoding core config: %s\n", err.Error())
 		os.Exit(1)
 	}
+
+	// ensure backwards compatibility, if tracing is enabled default to opencensus as there are parts of the code
+	// that rely on a configured opencensus singleton.
+	if c.TracingEnabled && c.TracingService == "" {
+		c.TracingService = tracingOC
+	}
+
 	return c
 }
 
diff --git a/go.mod b/go.mod
index aeefd821df..87d4dc3d95 100644
--- a/go.mod
+++ b/go.mod
@@ -58,9 +58,15 @@ require (
 	github.com/tus/tusd v1.1.1-0.20200416115059-9deabf9d80c2
 	go.mongodb.org/mongo-driver v1.5.1 // indirect
 	go.opencensus.io v0.23.0
+	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.22.0
+	go.opentelemetry.io/otel v1.0.0-RC2
+	go.opentelemetry.io/otel/exporters/jaeger v1.0.0-RC2
+	go.opentelemetry.io/otel/metric v0.20.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.0.0-RC2
+	go.opentelemetry.io/otel/trace v1.0.0-RC2
 	golang.org/x/crypto v0.0.0-20201216223049-8b5274cf687f
 	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
-	golang.org/x/sys v0.0.0-20210423082822-04245dca01da
+	golang.org/x/sys v0.0.0-20210423185535-09eb48e85fd7
 	golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1
 	google.golang.org/genproto v0.0.0-20200806141610-86f49bd18e98 // indirect
 	google.golang.org/grpc v1.39.1
diff --git a/go.sum b/go.sum
index cf760b4ea4..49b6db115d 100644
--- a/go.sum
+++ b/go.sum
@@ -597,6 +597,23 @@ go.opencensus.io v0.22.3/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.23.0 h1:gqCw0LfLxScz8irSi8exQc7fyQ0fKQU/qnC/X8+V/1M=
 go.opencensus.io v0.23.0/go.mod h1:XItmlyltB5F7CS4xOC1DcqMoFqwtC6OG2xF7mCv7P7E=
+go.opentelemetry.io/contrib v0.22.0 h1:0F7gDEjgb1WGn4ODIjaCAg75hmqF+UN0LiVgwxsCodc=
+go.opentelemetry.io/contrib v0.22.0/go.mod h1:EH4yDYeNoaTqn/8yCWQmfNB78VHfGX2Jt2bvnvzBlGM=
+go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.22.0 h1:TjqELdtCtlOJQrTnXd2y+RP6wXKZUnnJer0HR0CSo18=
+go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.22.0/go.mod h1:KjqwX4uJNaj479ZjFpADOMJKOM4rBXq4kN7nbeuGKrY=
+go.opentelemetry.io/otel v0.20.0/go.mod h1:Y3ugLH2oa81t5QO+Lty+zXf8zC9L26ax4Nzoxm/dooo=
+go.opentelemetry.io/otel v1.0.0-RC2 h1:SHhxSjB+omnGZPgGlKe+QMp3MyazcOHdQ8qwo89oKbg=
+go.opentelemetry.io/otel v1.0.0-RC2/go.mod h1:w1thVQ7qbAy8MHb0IFj8a5Q2QU0l2ksf8u/CN8m3NOM=
+go.opentelemetry.io/otel/exporters/jaeger v1.0.0-RC2 h1:RF0nWsIDpDBe+s06lkLxUw9CWQUAhO6hBSxxB7dz45s=
+go.opentelemetry.io/otel/exporters/jaeger v1.0.0-RC2/go.mod h1:sZZqN3Vb0iT+NE6mZ1S7sNyH3t4PFk6ElK5TLGFBZ7E=
+go.opentelemetry.io/otel/metric v0.20.0/go.mod h1:598I5tYlH1vzBjn+BTuhzTCSb/9debfNp6R3s7Pr1eU=
+go.opentelemetry.io/otel/oteltest v0.20.0/go.mod h1:L7bgKf9ZB7qCwT9Up7i9/pn0PWIa9FqQ2IQ8LoxiGnw=
+go.opentelemetry.io/otel/oteltest v1.0.0-RC2/go.mod h1:kiQ4tw5tAL4JLTbcOYwK1CWI1HkT5aiLzHovgOVnz/A=
+go.opentelemetry.io/otel/sdk v1.0.0-RC2 h1:ROuteeSCBaZNjiT9JcFzZepmInDvLktR28Y6qKo8bCs=
+go.opentelemetry.io/otel/sdk v1.0.0-RC2/go.mod h1:fgwHyiDn4e5k40TD9VX243rOxXR+jzsWBZYA2P5jpEw=
+go.opentelemetry.io/otel/trace v0.20.0/go.mod h1:6GjCW8zgDjwGHGa6GkyeB8+/5vjT16gUEi0Nf1iBdgw=
+go.opentelemetry.io/otel/trace v1.0.0-RC2 h1:dunAP0qDULMIT82atj34m5RgvsIK6LcsXf1c/MsYg1w=
+go.opentelemetry.io/otel/trace v1.0.0-RC2/go.mod h1:JPQ+z6nNw9mqEGT8o3eoPTdnNI+Aj5JcxEsVGREIAy4=
 go.uber.org/atomic v1.3.2/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/atomic v1.5.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
@@ -757,6 +774,8 @@ golang.org/x/sys v0.0.0-20210112080510-489259a85091/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da h1:b3NXsE2LusjYGGjL5bxEVZZORm/YEFFrWFjR8eFrw/c=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423185535-09eb48e85fd7 h1:iGu644GcxtEcrInvDsQRCwJjtCIOlT2V7IRt6ah2Whw=
+golang.org/x/sys v0.0.0-20210423185535-09eb48e85fd7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1 h1:v+OssWQX+hTHEmOBgwxdZxK4zHq3yOs8F9J7mk0PY8E=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
diff --git a/internal/grpc/interceptors/appctx/appctx.go b/internal/grpc/interceptors/appctx/appctx.go
index 428a2109d4..2ff8e92e59 100644
--- a/internal/grpc/interceptors/appctx/appctx.go
+++ b/internal/grpc/interceptors/appctx/appctx.go
@@ -23,16 +23,13 @@ import (
 
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/rs/zerolog"
-	"go.opencensus.io/trace"
 	"google.golang.org/grpc"
 )
 
 // NewUnary returns a new unary interceptor that creates the application context.
 func NewUnary(log zerolog.Logger) grpc.UnaryServerInterceptor {
 	interceptor := func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
-		span := trace.FromContext(ctx)
-		sub := log.With().Str("traceid", span.SpanContext().TraceID.String()).Logger()
-		ctx = appctx.WithLogger(ctx, &sub)
+		ctx = appctx.WithLogger(ctx, &log)
 		res, err := handler(ctx, req)
 		return res, err
 	}
@@ -43,9 +40,7 @@ func NewUnary(log zerolog.Logger) grpc.UnaryServerInterceptor {
 // that creates the application context.
 func NewStream(log zerolog.Logger) grpc.StreamServerInterceptor {
 	interceptor := func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
-		span := trace.FromContext(ss.Context())
-		sub := log.With().Str("traceid", span.SpanContext().TraceID.String()).Logger()
-		ctx := appctx.WithLogger(ss.Context(), &sub)
+		ctx := appctx.WithLogger(ss.Context(), &log)
 		wrapped := newWrappedServerStream(ctx, ss)
 		err := handler(srv, wrapped)
 		return err
diff --git a/internal/grpc/interceptors/auth/auth.go b/internal/grpc/interceptors/auth/auth.go
index 8151013c81..fb8d394c8c 100644
--- a/internal/grpc/interceptors/auth/auth.go
+++ b/internal/grpc/interceptors/auth/auth.go
@@ -32,7 +32,6 @@ import (
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
-	"go.opencensus.io/trace"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
@@ -80,12 +79,9 @@ func NewUnary(m map[string]interface{}, unprotected []string) (grpc.UnaryServerI
 	}
 
 	interceptor := func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
-		ctx, span := trace.StartSpan(ctx, "auth")
-		defer span.End()
 		log := appctx.GetLogger(ctx)
 
 		if utils.Skip(info.FullMethod, unprotected) {
-			span.AddAttributes(trace.BoolAttribute("auth_enabled", false))
 			log.Debug().Str("method", info.FullMethod).Msg("skipping auth")
 
 			// If a token is present, set it anyway, as we might need the user info
@@ -100,8 +96,6 @@ func NewUnary(m map[string]interface{}, unprotected []string) (grpc.UnaryServerI
 			return handler(ctx, req)
 		}
 
-		span.AddAttributes(trace.BoolAttribute("auth_enabled", true))
-
 		tkn, ok := token.ContextGetToken(ctx)
 
 		if !ok || tkn == "" {
@@ -116,14 +110,6 @@ func NewUnary(m map[string]interface{}, unprotected []string) (grpc.UnaryServerI
 			return nil, status.Errorf(codes.PermissionDenied, "auth: core access token is invalid")
 		}
 
-		// store user and core access token in context.
-		span.AddAttributes(
-			trace.StringAttribute("id.idp", u.Id.Idp),
-			trace.StringAttribute("id.opaque_id", u.Id.OpaqueId),
-			trace.StringAttribute("username", u.Username),
-			trace.StringAttribute("token", tkn))
-		span.AddAttributes(trace.StringAttribute("user", u.String()), trace.StringAttribute("token", tkn))
-
 		ctx = user.ContextSetUser(ctx, u)
 		return handler(ctx, req)
 	}
diff --git a/internal/grpc/services/gateway/storageprovider.go b/internal/grpc/services/gateway/storageprovider.go
index d13c1d9d61..2e00507119 100644
--- a/internal/grpc/services/gateway/storageprovider.go
+++ b/internal/grpc/services/gateway/storageprovider.go
@@ -28,6 +28,8 @@ import (
 	"sync"
 	"time"
 
+	rtrace "github.com/cs3org/reva/pkg/trace"
+
 	collaboration "github.com/cs3org/go-cs3apis/cs3/sharing/collaboration/v1beta1"
 	types "github.com/cs3org/go-cs3apis/cs3/types/v1beta1"
 
@@ -836,15 +838,17 @@ func (s *svc) Delete(ctx context.Context, req *provider.DeleteRequest) (*provide
 		}, nil
 	}
 
+	ctx, span := rtrace.Provider.Tracer("reva").Start(ctx, "Delete")
+	defer span.End()
+
 	if !s.inSharedFolder(ctx, p) {
 		return s.delete(ctx, req)
 	}
 
 	if s.isSharedFolder(ctx, p) {
 		// TODO(labkode): deleting share names should be allowed, means unmounting.
-		log.Debug().Msgf("path:%s points to shared folder or share name", p)
 		err := errtypes.BadRequest("gateway: cannot delete share folder or share name: path=" + p)
-		log.Err(err).Msg("gateway: error creating container")
+		span.RecordError(err)
 		return &provider.DeleteResponse{
 			Status: status.NewInvalidArg(ctx, "path points to share folder or share name"),
 		}, nil
diff --git a/internal/http/interceptors/appctx/appctx.go b/internal/http/interceptors/appctx/appctx.go
index aa959c5590..b3277bf7f1 100644
--- a/internal/http/interceptors/appctx/appctx.go
+++ b/internal/http/interceptors/appctx/appctx.go
@@ -26,7 +26,6 @@ import (
 
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/rs/zerolog"
-	"go.opencensus.io/trace"
 )
 
 // New returns a new HTTP middleware that stores the log
@@ -41,13 +40,7 @@ func New(log zerolog.Logger) func(http.Handler) http.Handler {
 func handler(log zerolog.Logger, h http.Handler) http.Handler {
 
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		ctx := r.Context()
-
-		// trace is set on the httpserver.go file as the outermost wrapper handler.
-		span := trace.FromContext(ctx)
-		sub := log.With().Str("traceid", span.SpanContext().TraceID.String()).Logger()
-		ctx = appctx.WithLogger(ctx, &sub)
-
+		ctx := appctx.WithLogger(r.Context(), &log)
 		r = r.WithContext(ctx)
 		h.ServeHTTP(w, r)
 	})
diff --git a/internal/http/services/owncloud/ocdav/delete.go b/internal/http/services/owncloud/ocdav/delete.go
index 8b221a10c0..dab521280b 100644
--- a/internal/http/services/owncloud/ocdav/delete.go
+++ b/internal/http/services/owncloud/ocdav/delete.go
@@ -24,23 +24,20 @@ import (
 	"net/http"
 	"path"
 
+	rtrace "github.com/cs3org/reva/pkg/trace"
+
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
 	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/rs/zerolog"
-	"go.opencensus.io/trace"
 )
 
 func (s *svc) handlePathDelete(w http.ResponseWriter, r *http.Request, ns string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "delete")
-	defer span.End()
-
 	fn := path.Join(ns, r.URL.Path)
 
-	sublog := appctx.GetLogger(ctx).With().Str("path", fn).Logger()
+	sublog := appctx.GetLogger(r.Context()).With().Str("path", fn).Logger()
 	ref := &provider.Reference{Path: fn}
-	s.handleDelete(ctx, w, r, ref, sublog)
+	s.handleDelete(r.Context(), w, r, ref, sublog)
 }
 
 func (s *svc) handleDelete(ctx context.Context, w http.ResponseWriter, r *http.Request, ref *provider.Reference, log zerolog.Logger) {
@@ -51,9 +48,13 @@ func (s *svc) handleDelete(ctx context.Context, w http.ResponseWriter, r *http.R
 		return
 	}
 
+	ctx, span := rtrace.Provider.Tracer("reva").Start(ctx, "delete")
+	defer span.End()
+
 	req := &provider.DeleteRequest{Ref: ref}
 	res, err := client.Delete(ctx, req)
 	if err != nil {
+		span.RecordError(err)
 		log.Error().Err(err).Msg("error performing delete grpc request")
 		w.WriteHeader(http.StatusInternalServerError)
 		return
@@ -84,8 +85,10 @@ func (s *svc) handleDelete(ctx context.Context, w http.ResponseWriter, r *http.R
 			})
 			HandleWebdavError(&log, w, b, err)
 		}
+
 		HandleErrorStatus(&log, w, res.Status)
 		return
 	}
+
 	w.WriteHeader(http.StatusNoContent)
 }
diff --git a/internal/http/services/owncloud/ocdav/propfind.go b/internal/http/services/owncloud/ocdav/propfind.go
index afd1454d48..dc626c215f 100644
--- a/internal/http/services/owncloud/ocdav/propfind.go
+++ b/internal/http/services/owncloud/ocdav/propfind.go
@@ -32,7 +32,7 @@ import (
 	"strings"
 	"time"
 
-	"go.opencensus.io/trace"
+	"go.opentelemetry.io/otel/propagation"
 
 	userv1beta1 "github.com/cs3org/go-cs3apis/cs3/identity/user/v1beta1"
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
@@ -41,9 +41,11 @@ import (
 	"github.com/cs3org/reva/internal/grpc/services/storageprovider"
 	"github.com/cs3org/reva/internal/http/services/owncloud/ocs/conversions"
 	"github.com/cs3org/reva/pkg/appctx"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	ctxuser "github.com/cs3org/reva/pkg/user"
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/rs/zerolog"
+	"go.opentelemetry.io/otel/attribute"
 )
 
 const (
@@ -63,10 +65,12 @@ const (
 
 // ns is the namespace that is prefixed to the path in the cs3 namespace
 func (s *svc) handlePathPropfind(w http.ResponseWriter, r *http.Request, ns string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "propfind")
+	ctx := rtrace.Propagator.Extract(r.Context(), propagation.HeaderCarrier(r.Header))
+	ctx, span := rtrace.Provider.Tracer("reva").Start(ctx, fmt.Sprintf("%s %v", r.Method, r.URL.Path))
 	defer span.End()
 
+	span.SetAttributes(attribute.String("component", "ocdav"))
+
 	fn := path.Join(ns, r.URL.Path)
 
 	sublog := appctx.GetLogger(ctx).With().Str("path", fn).Logger()
diff --git a/pkg/publicshare/manager/json/json.go b/pkg/publicshare/manager/json/json.go
index 0ae33a0286..d7a047a369 100644
--- a/pkg/publicshare/manager/json/json.go
+++ b/pkg/publicshare/manager/json/json.go
@@ -44,7 +44,6 @@ import (
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
-	"go.opencensus.io/trace"
 )
 
 func init() {
@@ -438,12 +437,6 @@ func (m *manager) revokeExpiredPublicShare(ctx context.Context, s *link.PublicSh
 	m.mutex.Unlock()
 	defer m.mutex.Lock()
 
-	span := trace.FromContext(ctx)
-	span.AddAttributes(
-		trace.StringAttribute("operation", "delete expired share"),
-		trace.StringAttribute("opaqueId", s.Id.OpaqueId),
-	)
-
 	err := m.RevokePublicShare(ctx, u, &link.PublicShareReference{
 		Spec: &link.PublicShareReference_Id{
 			Id: &link.PublicShareId{
diff --git a/pkg/rgrpc/rgrpc.go b/pkg/rgrpc/rgrpc.go
index a5ad5c55da..7e78e33bfe 100644
--- a/pkg/rgrpc/rgrpc.go
+++ b/pkg/rgrpc/rgrpc.go
@@ -30,11 +30,12 @@ import (
 	"github.com/cs3org/reva/internal/grpc/interceptors/recovery"
 	"github.com/cs3org/reva/internal/grpc/interceptors/token"
 	"github.com/cs3org/reva/pkg/sharedconf"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
 	"github.com/rs/zerolog"
-	"go.opencensus.io/plugin/ocgrpc"
+	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/reflection"
 )
@@ -195,7 +196,7 @@ func (s *Server) registerServices() error {
 	if err != nil {
 		return err
 	}
-	opts = append(opts, grpc.StatsHandler(&ocgrpc.ServerHandler{}))
+	opts = append(opts)
 	grpcServer := grpc.NewServer(opts...)
 
 	for _, svc := range s.services {
@@ -281,6 +282,12 @@ func (s *Server) getInterceptors(unprotected []string) ([]grpc.ServerOption, err
 		s.log.Info().Msgf("rgrpc: chaining grpc unary interceptor %s with priority %d", t.Name, t.Priority)
 	}
 
+	unaryInterceptors = append(unaryInterceptors,
+		otelgrpc.UnaryServerInterceptor(
+			otelgrpc.WithTracerProvider(rtrace.Provider),
+			otelgrpc.WithPropagators(rtrace.Propagator)),
+	)
+
 	unaryInterceptors = append([]grpc.UnaryServerInterceptor{
 		appctx.NewUnary(s.log),
 		token.NewUnary(),
diff --git a/pkg/rgrpc/status/status.go b/pkg/rgrpc/status/status.go
index 5be9c670d0..2ad75264fc 100644
--- a/pkg/rgrpc/status/status.go
+++ b/pkg/rgrpc/status/status.go
@@ -34,8 +34,8 @@ import (
 // NewOK returns a Status with CODE_OK.
 func NewOK(ctx context.Context) *rpc.Status {
 	return &rpc.Status{
-		Code:  rpc.Code_CODE_OK,
-		Trace: getTrace(ctx),
+		Code: rpc.Code_CODE_OK,
+		//Trace: getTrace(ctx),
 	}
 }
 
@@ -46,7 +46,7 @@ func NewNotFound(ctx context.Context, msg string) *rpc.Status {
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_NOT_FOUND,
 		Message: msg,
-		Trace:   getTrace(ctx),
+		//Trace:   getTrace(ctx),
 	}
 }
 
@@ -57,7 +57,7 @@ func NewInvalid(ctx context.Context, msg string) *rpc.Status {
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_INVALID_ARGUMENT,
 		Message: msg,
-		Trace:   getTrace(ctx),
+		//Trace:   getTrace(ctx),
 	}
 }
 
@@ -74,7 +74,7 @@ func NewInternal(ctx context.Context, err error, msg string) *rpc.Status {
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_INTERNAL,
 		Message: msg,
-		Trace:   getTrace(ctx),
+		//Trace:   getTrace(ctx),
 	}
 }
 
@@ -85,7 +85,7 @@ func NewUnauthenticated(ctx context.Context, err error, msg string) *rpc.Status
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_UNAUTHENTICATED,
 		Message: msg,
-		Trace:   getTrace(ctx),
+		//Trace:   getTrace(ctx),
 	}
 }
 
@@ -97,7 +97,7 @@ func NewPermissionDenied(ctx context.Context, err error, msg string) *rpc.Status
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_PERMISSION_DENIED,
 		Message: msg,
-		Trace:   getTrace(ctx),
+		//Trace:   getTrace(ctx),
 	}
 }
 
@@ -109,7 +109,7 @@ func NewInsufficientStorage(ctx context.Context, err error, msg string) *rpc.Sta
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_INSUFFICIENT_STORAGE,
 		Message: msg,
-		Trace:   getTrace(ctx),
+		//Trace:   getTrace(ctx),
 	}
 }
 
@@ -120,7 +120,7 @@ func NewUnimplemented(ctx context.Context, err error, msg string) *rpc.Status {
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_UNIMPLEMENTED,
 		Message: msg,
-		Trace:   getTrace(ctx),
+		//Trace:   getTrace(ctx),
 	}
 }
 
@@ -131,7 +131,7 @@ func NewAlreadyExists(ctx context.Context, err error, msg string) *rpc.Status {
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_ALREADY_EXISTS,
 		Message: msg,
-		Trace:   getTrace(ctx),
+		//Trace:   getTrace(ctx),
 	}
 }
 
@@ -139,7 +139,7 @@ func NewAlreadyExists(ctx context.Context, err error, msg string) *rpc.Status {
 func NewInvalidArg(ctx context.Context, msg string) *rpc.Status {
 	return &rpc.Status{Code: rpc.Code_CODE_INVALID_ARGUMENT,
 		Message: msg,
-		Trace:   getTrace(ctx),
+		//Trace:   getTrace(ctx),
 	}
 }
 
diff --git a/pkg/rgrpc/todo/pool/pool.go b/pkg/rgrpc/todo/pool/pool.go
index 5003ba711b..3ab9535bc9 100644
--- a/pkg/rgrpc/todo/pool/pool.go
+++ b/pkg/rgrpc/todo/pool/pool.go
@@ -21,6 +21,8 @@ package pool
 import (
 	"sync"
 
+	"go.opentelemetry.io/otel/propagation"
+
 	appprovider "github.com/cs3org/go-cs3apis/cs3/app/provider/v1beta1"
 	appregistry "github.com/cs3org/go-cs3apis/cs3/app/registry/v1beta1"
 	applicationauth "github.com/cs3org/go-cs3apis/cs3/auth/applications/v1beta1"
@@ -39,7 +41,9 @@ import (
 	storageprovider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
 	storageregistry "github.com/cs3org/go-cs3apis/cs3/storage/registry/v1beta1"
 	datatx "github.com/cs3org/go-cs3apis/cs3/tx/v1beta1"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"go.opencensus.io/plugin/ocgrpc"
+	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 	"google.golang.org/grpc"
 )
 
@@ -90,7 +94,19 @@ func NewConn(endpoint string) (*grpc.ClientConn, error) {
 		grpc.WithStatsHandler(&ocgrpc.ClientHandler{}),
 		grpc.WithDefaultCallOptions(
 			grpc.MaxCallRecvMsgSize(maxCallRecvMsgSize),
-		))
+		),
+		// TODO(refs) add this DialOption only if tracing is enabled. Unaware of the drawbacks.
+		grpc.WithUnaryInterceptor(
+			otelgrpc.UnaryClientInterceptor(
+				otelgrpc.WithTracerProvider(
+					rtrace.Provider,
+				),
+				otelgrpc.WithPropagators(
+					propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}),
+				),
+			),
+		),
+	)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/rhttp/rhttp.go b/pkg/rhttp/rhttp.go
index 378a02dd39..5e64d172a0 100644
--- a/pkg/rhttp/rhttp.go
+++ b/pkg/rhttp/rhttp.go
@@ -33,11 +33,12 @@ import (
 	"github.com/cs3org/reva/internal/http/interceptors/providerauthorizer"
 	"github.com/cs3org/reva/pkg/rhttp/global"
 	"github.com/cs3org/reva/pkg/rhttp/router"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
 	"github.com/rs/zerolog"
 	"go.opencensus.io/plugin/ochttp"
-	"go.opencensus.io/trace"
+	"go.opentelemetry.io/otel/propagation"
 )
 
 // New returns a new server
@@ -301,10 +302,13 @@ func (s *Server) getHandler() (http.Handler, error) {
 
 func traceHandler(name string, h http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		ctx, span := trace.StartSpan(r.Context(), name)
-		r = r.WithContext(ctx)
-		h.ServeHTTP(w, r)
-		span.End()
+		ctx := rtrace.Propagator.Extract(r.Context(), propagation.HeaderCarrier(r.Header))
+		t := rtrace.Provider.Tracer("reva")
+		ctx, span := t.Start(ctx, name)
+		defer span.End()
+
+		rtrace.Propagator.Inject(ctx, propagation.HeaderCarrier(r.Header))
+		h.ServeHTTP(w, r.WithContext(ctx))
 	})
 }
 
diff --git a/pkg/trace/trace.go b/pkg/trace/trace.go
new file mode 100644
index 0000000000..4ac829fbda
--- /dev/null
+++ b/pkg/trace/trace.go
@@ -0,0 +1,33 @@
+package trace
+
+import (
+	"go.opentelemetry.io/otel/exporters/jaeger"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
+	"go.opentelemetry.io/otel/trace"
+)
+
+var (
+	// Propagator is the default Reva propagator.
+	Propagator = propagation.NewCompositeTextMapPropagator(propagation.Baggage{}, propagation.TraceContext{})
+
+	// Provider is the default Reva tracer provider.
+	Provider = trace.NewNoopTracerProvider()
+)
+
+func SetTraceProvider(url string) {
+	exp, err := jaeger.New(jaeger.WithCollectorEndpoint(jaeger.WithEndpoint(url)))
+	if err != nil {
+		panic(err)
+	}
+
+	Provider = sdktrace.NewTracerProvider(
+		sdktrace.WithBatcher(exp),
+		sdktrace.WithResource(resource.NewWithAttributes(
+			semconv.SchemaURL,
+			semconv.ServiceNameKey.String("reva"),
+		)),
+	)
+}

From 813bf8371f69f3ecf179c7e83bbfe87b6c756466 Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Wed, 11 Aug 2021 12:26:07 +0200
Subject: [PATCH 02/14] linter: comment SetTraceProvider

---
 pkg/trace/trace.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pkg/trace/trace.go b/pkg/trace/trace.go
index 4ac829fbda..adab919e62 100644
--- a/pkg/trace/trace.go
+++ b/pkg/trace/trace.go
@@ -17,6 +17,7 @@ var (
 	Provider = trace.NewNoopTracerProvider()
 )
 
+// SetTraceProvider sets the TracerProvider at a package level.
 func SetTraceProvider(url string) {
 	exp, err := jaeger.New(jaeger.WithCollectorEndpoint(jaeger.WithEndpoint(url)))
 	if err != nil {

From 8251303a3673ab835c8ab455c53a77c2566889b1 Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Wed, 11 Aug 2021 12:38:29 +0200
Subject: [PATCH 03/14] traces: revert call to getTrace from context

---
 pkg/rgrpc/status/status.go | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/pkg/rgrpc/status/status.go b/pkg/rgrpc/status/status.go
index 2ad75264fc..5be9c670d0 100644
--- a/pkg/rgrpc/status/status.go
+++ b/pkg/rgrpc/status/status.go
@@ -34,8 +34,8 @@ import (
 // NewOK returns a Status with CODE_OK.
 func NewOK(ctx context.Context) *rpc.Status {
 	return &rpc.Status{
-		Code: rpc.Code_CODE_OK,
-		//Trace: getTrace(ctx),
+		Code:  rpc.Code_CODE_OK,
+		Trace: getTrace(ctx),
 	}
 }
 
@@ -46,7 +46,7 @@ func NewNotFound(ctx context.Context, msg string) *rpc.Status {
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_NOT_FOUND,
 		Message: msg,
-		//Trace:   getTrace(ctx),
+		Trace:   getTrace(ctx),
 	}
 }
 
@@ -57,7 +57,7 @@ func NewInvalid(ctx context.Context, msg string) *rpc.Status {
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_INVALID_ARGUMENT,
 		Message: msg,
-		//Trace:   getTrace(ctx),
+		Trace:   getTrace(ctx),
 	}
 }
 
@@ -74,7 +74,7 @@ func NewInternal(ctx context.Context, err error, msg string) *rpc.Status {
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_INTERNAL,
 		Message: msg,
-		//Trace:   getTrace(ctx),
+		Trace:   getTrace(ctx),
 	}
 }
 
@@ -85,7 +85,7 @@ func NewUnauthenticated(ctx context.Context, err error, msg string) *rpc.Status
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_UNAUTHENTICATED,
 		Message: msg,
-		//Trace:   getTrace(ctx),
+		Trace:   getTrace(ctx),
 	}
 }
 
@@ -97,7 +97,7 @@ func NewPermissionDenied(ctx context.Context, err error, msg string) *rpc.Status
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_PERMISSION_DENIED,
 		Message: msg,
-		//Trace:   getTrace(ctx),
+		Trace:   getTrace(ctx),
 	}
 }
 
@@ -109,7 +109,7 @@ func NewInsufficientStorage(ctx context.Context, err error, msg string) *rpc.Sta
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_INSUFFICIENT_STORAGE,
 		Message: msg,
-		//Trace:   getTrace(ctx),
+		Trace:   getTrace(ctx),
 	}
 }
 
@@ -120,7 +120,7 @@ func NewUnimplemented(ctx context.Context, err error, msg string) *rpc.Status {
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_UNIMPLEMENTED,
 		Message: msg,
-		//Trace:   getTrace(ctx),
+		Trace:   getTrace(ctx),
 	}
 }
 
@@ -131,7 +131,7 @@ func NewAlreadyExists(ctx context.Context, err error, msg string) *rpc.Status {
 	return &rpc.Status{
 		Code:    rpc.Code_CODE_ALREADY_EXISTS,
 		Message: msg,
-		//Trace:   getTrace(ctx),
+		Trace:   getTrace(ctx),
 	}
 }
 
@@ -139,7 +139,7 @@ func NewAlreadyExists(ctx context.Context, err error, msg string) *rpc.Status {
 func NewInvalidArg(ctx context.Context, msg string) *rpc.Status {
 	return &rpc.Status{Code: rpc.Code_CODE_INVALID_ARGUMENT,
 		Message: msg,
-		//Trace:   getTrace(ctx),
+		Trace:   getTrace(ctx),
 	}
 }
 

From 6d571a1d5190f21abab5ae1d00a8de72ce55938b Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Wed, 11 Aug 2021 12:55:12 +0200
Subject: [PATCH 04/14] linter: add license

---
 pkg/trace/trace.go | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/pkg/trace/trace.go b/pkg/trace/trace.go
index adab919e62..c610131711 100644
--- a/pkg/trace/trace.go
+++ b/pkg/trace/trace.go
@@ -1,3 +1,21 @@
+// Copyright 2018-2021 CERN
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// In applying this license, CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
 package trace
 
 import (

From e60929cbc721572e66f81abcaaa4f858a5ee313a Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Thu, 12 Aug 2021 14:08:13 +0200
Subject: [PATCH 05/14] fix: wrong import

---
 internal/http/services/owncloud/ocdav/delete.go | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/internal/http/services/owncloud/ocdav/delete.go b/internal/http/services/owncloud/ocdav/delete.go
index 1c2473e77c..ed8f365539 100644
--- a/internal/http/services/owncloud/ocdav/delete.go
+++ b/internal/http/services/owncloud/ocdav/delete.go
@@ -24,11 +24,10 @@ import (
 	"net/http"
 	"path"
 
-	rtrace "github.com/cs3org/reva/pkg/trace"
-
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
 	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
 	"github.com/cs3org/reva/pkg/appctx"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/rs/zerolog"
 )
 
@@ -97,7 +96,7 @@ func (s *svc) handleDelete(ctx context.Context, w http.ResponseWriter, r *http.R
 
 func (s *svc) handleSpacesDelete(w http.ResponseWriter, r *http.Request, spaceID string) {
 	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "spaces_delete")
+	ctx, span := rtrace.Provider.Tracer("reva").Start(ctx, "spaces_delete")
 	defer span.End()
 
 	sublog := appctx.GetLogger(ctx).With().Logger()

From 50490cf6047c49c64854baddaf9f8fe22e5ab2fe Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Thu, 12 Aug 2021 16:02:09 +0200
Subject: [PATCH 06/14] linter: ineffectual assignment

---
 pkg/rgrpc/rgrpc.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/pkg/rgrpc/rgrpc.go b/pkg/rgrpc/rgrpc.go
index 7e78e33bfe..220fa50199 100644
--- a/pkg/rgrpc/rgrpc.go
+++ b/pkg/rgrpc/rgrpc.go
@@ -196,7 +196,6 @@ func (s *Server) registerServices() error {
 	if err != nil {
 		return err
 	}
-	opts = append(opts)
 	grpcServer := grpc.NewServer(opts...)
 
 	for _, svc := range s.services {

From ff4e80b459eaeeea58773941bb3d5706e8cd5746 Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Mon, 16 Aug 2021 10:00:42 +0200
Subject: [PATCH 07/14] add changelog

---
 changelog/unreleased/opentelemetry.md | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 changelog/unreleased/opentelemetry.md

diff --git a/changelog/unreleased/opentelemetry.md b/changelog/unreleased/opentelemetry.md
new file mode 100644
index 0000000000..da2747c401
--- /dev/null
+++ b/changelog/unreleased/opentelemetry.md
@@ -0,0 +1,13 @@
+Enhancement: Replace OpenCensus with OpenTelemetry
+
+What is [OpenTelemetry](https://opentelemetry.io/docs/concepts/what-is-opentelemetry/)?
+
+- [open standard](https://github.com/open-telemetry/opentelemetry-specification)
+- sandbox CNCF project.
+- formed through a merger of the OpenTracing and OpenCensus.
+
+> OpenCensus and OpenTracing have merged to form OpenTelemetry, which serves as the next major version of OpenCensus and OpenTracing. OpenTelemetry will offer backwards compatibility with existing OpenCensus integrations, and we will continue to make security patches to existing OpenCensus libraries for two years.
+
+There is a lot of outdated documentation as a result of this merger, and we will be better off adopting the latest standard and libraries.
+
+https://github.com/cs3org/reva/pull/1984
\ No newline at end of file

From 76990baa3e6e4b9219ffd737bd3a5ac086aa3794 Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Mon, 16 Aug 2021 10:35:46 +0200
Subject: [PATCH 08/14] add changelog

---
 changelog/unreleased/opentelemetry.md | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/changelog/unreleased/opentelemetry.md b/changelog/unreleased/opentelemetry.md
index da2747c401..ee5837c04e 100644
--- a/changelog/unreleased/opentelemetry.md
+++ b/changelog/unreleased/opentelemetry.md
@@ -1,10 +1,6 @@
 Enhancement: Replace OpenCensus with OpenTelemetry
 
-What is [OpenTelemetry](https://opentelemetry.io/docs/concepts/what-is-opentelemetry/)?
-
-- [open standard](https://github.com/open-telemetry/opentelemetry-specification)
-- sandbox CNCF project.
-- formed through a merger of the OpenTracing and OpenCensus.
+OpenTelemetry](https://opentelemetry.io/docs/concepts/what-is-opentelemetry/) is an [open standard](https://github.com/open-telemetry/opentelemetry-specification) a sandbox CNCF project and it was formed through a merger of the OpenTracing and OpenCensus.
 
 > OpenCensus and OpenTracing have merged to form OpenTelemetry, which serves as the next major version of OpenCensus and OpenTracing. OpenTelemetry will offer backwards compatibility with existing OpenCensus integrations, and we will continue to make security patches to existing OpenCensus libraries for two years.
 

From 38ebfd67665c2ac7d400b18090d05c6679ca8b67 Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Mon, 16 Aug 2021 14:41:44 +0200
Subject: [PATCH 09/14] traces: remove redundant context extraction

---
 internal/http/services/owncloud/ocdav/propfind.go | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/internal/http/services/owncloud/ocdav/propfind.go b/internal/http/services/owncloud/ocdav/propfind.go
index 3a715b2dca..5fe26babae 100644
--- a/internal/http/services/owncloud/ocdav/propfind.go
+++ b/internal/http/services/owncloud/ocdav/propfind.go
@@ -33,7 +33,6 @@ import (
 	"time"
 
 	"go.opencensus.io/trace"
-	"go.opentelemetry.io/otel/propagation"
 
 	userv1beta1 "github.com/cs3org/go-cs3apis/cs3/identity/user/v1beta1"
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
@@ -66,8 +65,7 @@ const (
 
 // ns is the namespace that is prefixed to the path in the cs3 namespace
 func (s *svc) handlePathPropfind(w http.ResponseWriter, r *http.Request, ns string) {
-	ctx := rtrace.Propagator.Extract(r.Context(), propagation.HeaderCarrier(r.Header))
-	ctx, span := rtrace.Provider.Tracer("reva").Start(ctx, fmt.Sprintf("%s %v", r.Method, r.URL.Path))
+	ctx, span := rtrace.Provider.Tracer("reva").Start(r.Context(), fmt.Sprintf("%s %v", r.Method, r.URL.Path))
 	defer span.End()
 
 	span.SetAttributes(attribute.String("component", "ocdav"))

From 4345158f81578a5cdc7a0f3c06cfe1a7f58039b6 Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Mon, 16 Aug 2021 15:53:33 +0200
Subject: [PATCH 10/14] traces: adopt further opentelemetry

---
 .../publicstorageprovider.go                  | 47 ++++++++++++-------
 .../storageprovider/storageprovider.go        | 18 ++++---
 internal/http/services/owncloud/ocdav/copy.go |  8 ++--
 internal/http/services/owncloud/ocdav/get.go  | 15 +++---
 internal/http/services/owncloud/ocdav/head.go |  9 ++--
 .../http/services/owncloud/ocdav/mkcol.go     |  8 ++--
 internal/http/services/owncloud/ocdav/move.go |  8 ++--
 .../http/services/owncloud/ocdav/propfind.go  |  5 +-
 .../http/services/owncloud/ocdav/proppatch.go |  9 ++--
 .../services/owncloud/ocdav/publicfile.go     |  8 ++--
 internal/http/services/owncloud/ocdav/put.go  |  8 ++--
 .../http/services/owncloud/ocdav/trashbin.go  | 12 ++---
 internal/http/services/owncloud/ocdav/tus.go  |  8 ++--
 .../http/services/owncloud/ocdav/versions.go  |  9 ++--
 pkg/rgrpc/status/status.go                    |  6 +--
 .../utils/decomposedfs/decomposedfs.go        | 29 ++++++++++++
 16 files changed, 110 insertions(+), 97 deletions(-)

diff --git a/internal/grpc/services/publicstorageprovider/publicstorageprovider.go b/internal/grpc/services/publicstorageprovider/publicstorageprovider.go
index 32bf2f485a..adde74160f 100644
--- a/internal/grpc/services/publicstorageprovider/publicstorageprovider.go
+++ b/internal/grpc/services/publicstorageprovider/publicstorageprovider.go
@@ -34,12 +34,13 @@ import (
 	"github.com/cs3org/reva/pkg/rgrpc"
 	"github.com/cs3org/reva/pkg/rgrpc/status"
 	"github.com/cs3org/reva/pkg/rgrpc/todo/pool"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
-	"go.opencensus.io/trace"
+	"go.opentelemetry.io/otel/attribute"
 	"google.golang.org/grpc"
-	codes "google.golang.org/grpc/codes"
+	"google.golang.org/grpc/codes"
 	gstatus "google.golang.org/grpc/status"
 )
 
@@ -305,12 +306,13 @@ func (s *service) DeleteStorageSpace(ctx context.Context, req *provider.DeleteSt
 }
 
 func (s *service) CreateContainer(ctx context.Context, req *provider.CreateContainerRequest) (*provider.CreateContainerResponse, error) {
-	ctx, span := trace.StartSpan(ctx, "CreateContainer")
+	ctx, span := rtrace.Provider.Tracer("publicstorageprovider").Start(ctx, "CreateContainer")
 	defer span.End()
 
-	span.AddAttributes(
-		trace.StringAttribute("ref", req.Ref.String()),
-	)
+	span.SetAttributes(attribute.KeyValue{
+		Key:   "reference",
+		Value: attribute.StringValue(req.Ref.String()),
+	})
 
 	cs3Ref, _, ls, st, err := s.translatePublicRefToCS3Ref(ctx, req.Ref)
 	switch {
@@ -344,12 +346,13 @@ func (s *service) CreateContainer(ctx context.Context, req *provider.CreateConta
 }
 
 func (s *service) Delete(ctx context.Context, req *provider.DeleteRequest) (*provider.DeleteResponse, error) {
-	ctx, span := trace.StartSpan(ctx, "Delete")
+	ctx, span := rtrace.Provider.Tracer("publicstorageprovider").Start(ctx, "Delete")
 	defer span.End()
 
-	span.AddAttributes(
-		trace.StringAttribute("ref", req.Ref.String()),
-	)
+	span.SetAttributes(attribute.KeyValue{
+		Key:   "reference",
+		Value: attribute.StringValue(req.Ref.String()),
+	})
 
 	cs3Ref, _, ls, st, err := s.translatePublicRefToCS3Ref(ctx, req.Ref)
 	switch {
@@ -383,12 +386,18 @@ func (s *service) Delete(ctx context.Context, req *provider.DeleteRequest) (*pro
 }
 
 func (s *service) Move(ctx context.Context, req *provider.MoveRequest) (*provider.MoveResponse, error) {
-	ctx, span := trace.StartSpan(ctx, "Move")
+	ctx, span := rtrace.Provider.Tracer("publicstorageprovider").Start(ctx, "Move")
 	defer span.End()
 
-	span.AddAttributes(
-		trace.StringAttribute("source", req.Source.String()),
-		trace.StringAttribute("destination", req.Destination.String()),
+	span.SetAttributes(
+		attribute.KeyValue{
+			Key:   "source",
+			Value: attribute.StringValue(req.Source.String()),
+		},
+		attribute.KeyValue{
+			Key:   "destination",
+			Value: attribute.StringValue(req.Destination.String()),
+		},
 	)
 
 	cs3RefSource, tknSource, ls, st, err := s.translatePublicRefToCS3Ref(ctx, req.Source)
@@ -440,12 +449,14 @@ func (s *service) Move(ctx context.Context, req *provider.MoveRequest) (*provide
 }
 
 func (s *service) Stat(ctx context.Context, req *provider.StatRequest) (*provider.StatResponse, error) {
-	ctx, span := trace.StartSpan(ctx, "Stat")
+	ctx, span := rtrace.Provider.Tracer("publicstorageprovider").Start(ctx, "Stat")
 	defer span.End()
 
-	span.AddAttributes(
-		trace.StringAttribute("ref", req.Ref.String()),
-	)
+	span.SetAttributes(
+		attribute.KeyValue{
+			Key:   "source",
+			Value: attribute.StringValue(req.Ref.String()),
+		})
 
 	tkn, relativePath, err := s.unwrap(ctx, req.Ref)
 	if err != nil {
diff --git a/internal/grpc/services/storageprovider/storageprovider.go b/internal/grpc/services/storageprovider/storageprovider.go
index 87d280a07a..df288be75c 100644
--- a/internal/grpc/services/storageprovider/storageprovider.go
+++ b/internal/grpc/services/storageprovider/storageprovider.go
@@ -20,19 +20,15 @@ package storageprovider
 
 import (
 	"context"
-	"sort"
-
-	// "encoding/json"
 	"fmt"
 	"net/url"
 	"os"
 	"path"
+	"sort"
 	"strconv"
 	"strings"
 
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
-
-	// link "github.com/cs3org/go-cs3apis/cs3/sharing/link/v1beta1"
 	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/cs3org/reva/pkg/errtypes"
@@ -42,10 +38,11 @@ import (
 	"github.com/cs3org/reva/pkg/rhttp/router"
 	"github.com/cs3org/reva/pkg/storage"
 	"github.com/cs3org/reva/pkg/storage/fs/registry"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
-	"go.opencensus.io/trace"
+	"go.opentelemetry.io/otel/attribute"
 	"google.golang.org/grpc"
 )
 
@@ -603,12 +600,13 @@ func (s *service) Move(ctx context.Context, req *provider.MoveRequest) (*provide
 }
 
 func (s *service) Stat(ctx context.Context, req *provider.StatRequest) (*provider.StatResponse, error) {
-	ctx, span := trace.StartSpan(ctx, "Stat")
+	ctx, span := rtrace.Provider.Tracer("reva").Start(ctx, "stat")
 	defer span.End()
 
-	span.AddAttributes(
-		trace.StringAttribute("ref", req.Ref.String()),
-	)
+	span.SetAttributes(attribute.KeyValue{
+		Key:   "reference",
+		Value: attribute.StringValue(req.Ref.String()),
+	})
 
 	newRef, err := s.unwrap(ctx, req.Ref)
 	if err != nil {
diff --git a/internal/http/services/owncloud/ocdav/copy.go b/internal/http/services/owncloud/ocdav/copy.go
index 8860da2e8f..8663d48c6a 100644
--- a/internal/http/services/owncloud/ocdav/copy.go
+++ b/internal/http/services/owncloud/ocdav/copy.go
@@ -34,9 +34,9 @@ import (
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/cs3org/reva/pkg/rhttp"
 	"github.com/cs3org/reva/pkg/rhttp/router"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/rs/zerolog"
-	"go.opencensus.io/trace"
 )
 
 type copy struct {
@@ -49,8 +49,7 @@ type copy struct {
 type intermediateDirRefFunc func() (*provider.Reference, *rpc.Status, error)
 
 func (s *svc) handlePathCopy(w http.ResponseWriter, r *http.Request, ns string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "copy")
+	ctx, span := rtrace.Provider.Tracer("reva").Start(r.Context(), "copy")
 	defer span.End()
 
 	src := path.Join(ns, r.URL.Path)
@@ -259,8 +258,7 @@ func (s *svc) executePathCopy(ctx context.Context, client gateway.GatewayAPIClie
 }
 
 func (s *svc) handleSpacesCopy(w http.ResponseWriter, r *http.Request, spaceID string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "spaces_copy")
+	ctx, span := rtrace.Provider.Tracer("reva").Start(r.Context(), "spaces_copy")
 	defer span.End()
 
 	dst, err := extractDestination(r)
diff --git a/internal/http/services/owncloud/ocdav/get.go b/internal/http/services/owncloud/ocdav/get.go
index ba5837db90..6bd08c52da 100644
--- a/internal/http/services/owncloud/ocdav/get.go
+++ b/internal/http/services/owncloud/ocdav/get.go
@@ -28,21 +28,19 @@ import (
 	"strings"
 	"time"
 
-	"github.com/cs3org/reva/internal/grpc/services/storageprovider"
-	"github.com/cs3org/reva/internal/http/services/datagateway"
-	"github.com/rs/zerolog"
-	"go.opencensus.io/trace"
-
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
 	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
+	"github.com/cs3org/reva/internal/grpc/services/storageprovider"
+	"github.com/cs3org/reva/internal/http/services/datagateway"
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/cs3org/reva/pkg/rhttp"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/cs3org/reva/pkg/utils"
+	"github.com/rs/zerolog"
 )
 
 func (s *svc) handlePathGet(w http.ResponseWriter, r *http.Request, ns string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "get")
+	ctx, span := rtrace.Provider.Tracer("reva").Start(r.Context(), "get")
 	defer span.End()
 
 	fn := path.Join(ns, r.URL.Path)
@@ -161,8 +159,7 @@ func (s *svc) handleGet(ctx context.Context, w http.ResponseWriter, r *http.Requ
 }
 
 func (s *svc) handleSpacesGet(w http.ResponseWriter, r *http.Request, spaceID string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "spaces_get")
+	ctx, span := rtrace.Provider.Tracer("reva").Start(r.Context(), "spaces_get")
 	defer span.End()
 
 	sublog := appctx.GetLogger(ctx).With().Str("path", r.URL.Path).Str("spaceid", spaceID).Str("handler", "get").Logger()
diff --git a/internal/http/services/owncloud/ocdav/head.go b/internal/http/services/owncloud/ocdav/head.go
index f74c7d5bc0..7b3094595b 100644
--- a/internal/http/services/owncloud/ocdav/head.go
+++ b/internal/http/services/owncloud/ocdav/head.go
@@ -27,18 +27,18 @@ import (
 	"strings"
 	"time"
 
+	rtrace "github.com/cs3org/reva/pkg/trace"
+
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
 	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
 	"github.com/cs3org/reva/internal/grpc/services/storageprovider"
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/rs/zerolog"
-	"go.opencensus.io/trace"
 )
 
 func (s *svc) handlePathHead(w http.ResponseWriter, r *http.Request, ns string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "head")
+	ctx, span := rtrace.Provider.Tracer("reva").Start(r.Context(), "head")
 	defer span.End()
 
 	fn := path.Join(ns, r.URL.Path)
@@ -89,8 +89,7 @@ func (s *svc) handleHead(ctx context.Context, w http.ResponseWriter, r *http.Req
 }
 
 func (s *svc) handleSpacesHead(w http.ResponseWriter, r *http.Request, spaceID string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "spaces_head")
+	ctx, span := rtrace.Provider.Tracer("reva").Start(r.Context(), "spaces_head")
 	defer span.End()
 
 	sublog := appctx.GetLogger(ctx).With().Str("spaceid", spaceID).Str("path", r.URL.Path).Logger()
diff --git a/internal/http/services/owncloud/ocdav/mkcol.go b/internal/http/services/owncloud/ocdav/mkcol.go
index c8707fbc32..ddee72b86b 100644
--- a/internal/http/services/owncloud/ocdav/mkcol.go
+++ b/internal/http/services/owncloud/ocdav/mkcol.go
@@ -27,13 +27,12 @@ import (
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
 	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
 	"github.com/cs3org/reva/pkg/appctx"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/rs/zerolog"
-	"go.opencensus.io/trace"
 )
 
 func (s *svc) handlePathMkcol(w http.ResponseWriter, r *http.Request, ns string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "mkcol")
+	ctx, span := rtrace.Provider.Tracer("reva").Start(r.Context(), "mkcol")
 	defer span.End()
 
 	fn := path.Join(ns, r.URL.Path)
@@ -51,8 +50,7 @@ func (s *svc) handlePathMkcol(w http.ResponseWriter, r *http.Request, ns string)
 }
 
 func (s *svc) handleSpacesMkCol(w http.ResponseWriter, r *http.Request, spaceID string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "spaces_mkcol")
+	ctx, span := rtrace.Provider.Tracer("reva").Start(r.Context(), "spaces_mkcol")
 	defer span.End()
 
 	sublog := appctx.GetLogger(ctx).With().Str("path", r.URL.Path).Str("spaceid", spaceID).Str("handler", "mkcol").Logger()
diff --git a/internal/http/services/owncloud/ocdav/move.go b/internal/http/services/owncloud/ocdav/move.go
index b1e7bc5139..376f57d72b 100644
--- a/internal/http/services/owncloud/ocdav/move.go
+++ b/internal/http/services/owncloud/ocdav/move.go
@@ -29,13 +29,12 @@ import (
 	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/cs3org/reva/pkg/rhttp/router"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/rs/zerolog"
-	"go.opencensus.io/trace"
 )
 
 func (s *svc) handlePathMove(w http.ResponseWriter, r *http.Request, ns string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "move")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "move")
 	defer span.End()
 
 	srcPath := path.Join(ns, r.URL.Path)
@@ -67,8 +66,7 @@ func (s *svc) handlePathMove(w http.ResponseWriter, r *http.Request, ns string)
 }
 
 func (s *svc) handleSpacesMove(w http.ResponseWriter, r *http.Request, srcSpaceID string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "spaces_move")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "spaces_move")
 	defer span.End()
 
 	dst, err := extractDestination(r)
diff --git a/internal/http/services/owncloud/ocdav/propfind.go b/internal/http/services/owncloud/ocdav/propfind.go
index 5fe26babae..0e9c99be88 100644
--- a/internal/http/services/owncloud/ocdav/propfind.go
+++ b/internal/http/services/owncloud/ocdav/propfind.go
@@ -32,8 +32,6 @@ import (
 	"strings"
 	"time"
 
-	"go.opencensus.io/trace"
-
 	userv1beta1 "github.com/cs3org/go-cs3apis/cs3/identity/user/v1beta1"
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
 	link "github.com/cs3org/go-cs3apis/cs3/sharing/link/v1beta1"
@@ -92,8 +90,7 @@ func (s *svc) handlePathPropfind(w http.ResponseWriter, r *http.Request, ns stri
 }
 
 func (s *svc) handleSpacesPropfind(w http.ResponseWriter, r *http.Request, spaceID string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "spaces_propfind")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "spaces_propfind")
 	defer span.End()
 
 	sublog := appctx.GetLogger(ctx).With().Str("path", r.URL.Path).Str("spaceid", spaceID).Logger()
diff --git a/internal/http/services/owncloud/ocdav/proppatch.go b/internal/http/services/owncloud/ocdav/proppatch.go
index 326550cf2d..2fb3a0f6a3 100644
--- a/internal/http/services/owncloud/ocdav/proppatch.go
+++ b/internal/http/services/owncloud/ocdav/proppatch.go
@@ -27,18 +27,16 @@ import (
 	"path"
 	"strings"
 
-	"go.opencensus.io/trace"
-
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
 	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
 	"github.com/cs3org/reva/pkg/appctx"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/pkg/errors"
 	"github.com/rs/zerolog"
 )
 
 func (s *svc) handlePathProppatch(w http.ResponseWriter, r *http.Request, ns string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "proppatch")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "proppatch")
 	defer span.End()
 
 	fn := path.Join(ns, r.URL.Path)
@@ -105,8 +103,7 @@ func (s *svc) handlePathProppatch(w http.ResponseWriter, r *http.Request, ns str
 }
 
 func (s *svc) handleSpacesProppatch(w http.ResponseWriter, r *http.Request, spaceID string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "spaces_proppatch")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "spaces_proppatch")
 	defer span.End()
 
 	sublog := appctx.GetLogger(ctx).With().Str("path", r.URL.Path).Str("spaceid", spaceID).Logger()
diff --git a/internal/http/services/owncloud/ocdav/publicfile.go b/internal/http/services/owncloud/ocdav/publicfile.go
index ba4cc78ee8..797f1e4d53 100644
--- a/internal/http/services/owncloud/ocdav/publicfile.go
+++ b/internal/http/services/owncloud/ocdav/publicfile.go
@@ -27,7 +27,7 @@ import (
 	typesv1beta1 "github.com/cs3org/go-cs3apis/cs3/types/v1beta1"
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/cs3org/reva/pkg/rhttp/router"
-	"go.opencensus.io/trace"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 )
 
 // PublicFileHandler handles requests on a shared file. it needs to be wrapped in a collection
@@ -87,8 +87,7 @@ func (h *PublicFileHandler) Handler(s *svc) http.Handler {
 }
 
 func (s *svc) adjustResourcePathInURL(w http.ResponseWriter, r *http.Request) bool {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "adjustResourcePathInURL")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "adjustResourcePathInURL")
 	defer span.End()
 
 	// find actual file name
@@ -130,8 +129,7 @@ func (s *svc) adjustResourcePathInURL(w http.ResponseWriter, r *http.Request) bo
 
 // ns is the namespace that is prefixed to the path in the cs3 namespace
 func (s *svc) handlePropfindOnToken(w http.ResponseWriter, r *http.Request, ns string, onContainer bool) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "token_propfind")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "token_propfind")
 	defer span.End()
 
 	tokenStatInfo := ctx.Value(tokenStatInfoKey{}).(*provider.ResourceInfo)
diff --git a/internal/http/services/owncloud/ocdav/put.go b/internal/http/services/owncloud/ocdav/put.go
index 9b8701ca3b..2e2c8225c8 100644
--- a/internal/http/services/owncloud/ocdav/put.go
+++ b/internal/http/services/owncloud/ocdav/put.go
@@ -34,9 +34,9 @@ import (
 	"github.com/cs3org/reva/pkg/errtypes"
 	"github.com/cs3org/reva/pkg/rhttp"
 	"github.com/cs3org/reva/pkg/storage/utils/chunking"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/rs/zerolog"
-	"go.opencensus.io/trace"
 )
 
 func sufferMacOSFinder(r *http.Request) bool {
@@ -105,8 +105,7 @@ func isContentRange(r *http.Request) bool {
 }
 
 func (s *svc) handlePathPut(w http.ResponseWriter, r *http.Request, ns string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "put")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "put")
 	defer span.End()
 
 	fn := path.Join(ns, r.URL.Path)
@@ -334,8 +333,7 @@ func (s *svc) handlePut(ctx context.Context, w http.ResponseWriter, r *http.Requ
 }
 
 func (s *svc) handleSpacesPut(w http.ResponseWriter, r *http.Request, spaceID string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "spaces_put")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "spaces_put")
 	defer span.End()
 
 	sublog := appctx.GetLogger(ctx).With().Str("spaceid", spaceID).Str("path", r.URL.Path).Logger()
diff --git a/internal/http/services/owncloud/ocdav/trashbin.go b/internal/http/services/owncloud/ocdav/trashbin.go
index 390a3cf479..3a8ea830ca 100644
--- a/internal/http/services/owncloud/ocdav/trashbin.go
+++ b/internal/http/services/owncloud/ocdav/trashbin.go
@@ -29,6 +29,8 @@ import (
 	"strings"
 	"time"
 
+	rtrace "github.com/cs3org/reva/pkg/trace"
+
 	gateway "github.com/cs3org/go-cs3apis/cs3/gateway/v1beta1"
 	userpb "github.com/cs3org/go-cs3apis/cs3/identity/user/v1beta1"
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
@@ -38,7 +40,6 @@ import (
 	"github.com/cs3org/reva/pkg/rgrpc/todo/pool"
 	"github.com/cs3org/reva/pkg/rhttp/router"
 	"github.com/cs3org/reva/pkg/utils"
-	"go.opencensus.io/trace"
 )
 
 // TrashbinHandler handles trashbin requests
@@ -142,8 +143,7 @@ func (h *TrashbinHandler) Handler(s *svc) http.Handler {
 }
 
 func (h *TrashbinHandler) listTrashbin(w http.ResponseWriter, r *http.Request, s *svc, u *userpb.User, key, itemPath string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "listTrashbin")
+	ctx, span := rtrace.Provider.Tracer("trash-bin").Start(r.Context(), "list_trashbin")
 	defer span.End()
 
 	depth := r.Header.Get(HeaderDepth)
@@ -431,8 +431,7 @@ func (h *TrashbinHandler) itemToPropResponse(ctx context.Context, s *svc, u *use
 }
 
 func (h *TrashbinHandler) restore(w http.ResponseWriter, r *http.Request, s *svc, u *userpb.User, dst, key, itemPath string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "restore")
+	ctx, span := rtrace.Provider.Tracer("trash-bin").Start(r.Context(), "restore")
 	defer span.End()
 
 	sublog := appctx.GetLogger(ctx).With().Logger()
@@ -591,8 +590,7 @@ func (h *TrashbinHandler) restore(w http.ResponseWriter, r *http.Request, s *svc
 
 // delete has only a key
 func (h *TrashbinHandler) delete(w http.ResponseWriter, r *http.Request, s *svc, u *userpb.User, key, itemPath string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "erase")
+	ctx, span := rtrace.Provider.Tracer("trash-bin").Start(r.Context(), "erase")
 	defer span.End()
 
 	sublog := appctx.GetLogger(ctx).With().Str("key", key).Logger()
diff --git a/internal/http/services/owncloud/ocdav/tus.go b/internal/http/services/owncloud/ocdav/tus.go
index 57c128aedc..0c1eb5c4e5 100644
--- a/internal/http/services/owncloud/ocdav/tus.go
+++ b/internal/http/services/owncloud/ocdav/tus.go
@@ -31,15 +31,14 @@ import (
 	typespb "github.com/cs3org/go-cs3apis/cs3/types/v1beta1"
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/cs3org/reva/pkg/rhttp"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/rs/zerolog"
 	tusd "github.com/tus/tusd/pkg/handler"
-	"go.opencensus.io/trace"
 )
 
 func (s *svc) handlePathTusPost(w http.ResponseWriter, r *http.Request, ns string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "tus-post")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "tus-post")
 	defer span.End()
 
 	// read filename from metadata
@@ -62,8 +61,7 @@ func (s *svc) handlePathTusPost(w http.ResponseWriter, r *http.Request, ns strin
 }
 
 func (s *svc) handleSpacesTusPost(w http.ResponseWriter, r *http.Request, spaceID string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "spaces-tus-post")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "spaces-tus-post")
 	defer span.End()
 
 	// read filename from metadata
diff --git a/internal/http/services/owncloud/ocdav/versions.go b/internal/http/services/owncloud/ocdav/versions.go
index 962808729b..b9af216c47 100644
--- a/internal/http/services/owncloud/ocdav/versions.go
+++ b/internal/http/services/owncloud/ocdav/versions.go
@@ -23,12 +23,13 @@ import (
 	"net/http"
 	"path"
 
+	rtrace "github.com/cs3org/reva/pkg/trace"
+
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
 	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
 	types "github.com/cs3org/go-cs3apis/cs3/types/v1beta1"
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/cs3org/reva/pkg/rhttp/router"
-	"go.opencensus.io/trace"
 )
 
 // VersionsHandler handles version requests
@@ -79,8 +80,7 @@ func (h *VersionsHandler) Handler(s *svc, rid *provider.ResourceId) http.Handler
 }
 
 func (h *VersionsHandler) doListVersions(w http.ResponseWriter, r *http.Request, s *svc, rid *provider.ResourceId) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "listVersions")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "listVersions")
 	defer span.End()
 
 	sublog := appctx.GetLogger(ctx).With().Interface("resourceid", rid).Logger()
@@ -182,8 +182,7 @@ func (h *VersionsHandler) doListVersions(w http.ResponseWriter, r *http.Request,
 }
 
 func (h *VersionsHandler) doRestore(w http.ResponseWriter, r *http.Request, s *svc, rid *provider.ResourceId, key string) {
-	ctx := r.Context()
-	ctx, span := trace.StartSpan(ctx, "restore")
+	ctx, span := rtrace.Provider.Tracer("ocdav").Start(r.Context(), "restore")
 	defer span.End()
 
 	sublog := appctx.GetLogger(ctx).With().Interface("resourceid", rid).Str("key", key).Logger()
diff --git a/pkg/rgrpc/status/status.go b/pkg/rgrpc/status/status.go
index 5be9c670d0..d1cb34bf15 100644
--- a/pkg/rgrpc/status/status.go
+++ b/pkg/rgrpc/status/status.go
@@ -28,7 +28,7 @@ import (
 	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
 	"github.com/cs3org/reva/pkg/appctx"
 	"github.com/cs3org/reva/pkg/errtypes"
-	"go.opencensus.io/trace"
+	"go.opentelemetry.io/otel/trace"
 )
 
 // NewOK returns a Status with CODE_OK.
@@ -170,6 +170,6 @@ func NewErrorFromCode(code rpc.Code, pkgname string) error {
 
 // internal function to attach the trace to a context
 func getTrace(ctx context.Context) string {
-	span := trace.FromContext(ctx)
-	return span.SpanContext().TraceID.String()
+	span := trace.SpanFromContext(ctx)
+	return span.SpanContext().TraceID().String()
 }
diff --git a/pkg/storage/utils/decomposedfs/decomposedfs.go b/pkg/storage/utils/decomposedfs/decomposedfs.go
index d851323f85..bfa698c23a 100644
--- a/pkg/storage/utils/decomposedfs/decomposedfs.go
+++ b/pkg/storage/utils/decomposedfs/decomposedfs.go
@@ -50,6 +50,11 @@ import (
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/pkg/errors"
 	"github.com/pkg/xattr"
+	"go.opentelemetry.io/otel/exporters/jaeger"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
+	"go.opentelemetry.io/otel/trace"
 )
 
 // PermissionsChecker defines an interface for checking permissions on a Node
@@ -85,6 +90,7 @@ type Decomposedfs struct {
 	tp           Tree
 	o            *options.Options
 	p            PermissionsChecker
+	tprov        trace.TracerProvider
 	chunkHandler *chunking.ChunkHandler
 }
 
@@ -107,6 +113,7 @@ func NewDefault(m map[string]interface{}, bs tree.Blobstore) (storage.FS, error)
 // New returns an implementation of the storage.FS interface that talks to
 // a local filesystem.
 func New(o *options.Options, lu *Lookup, p PermissionsChecker, tp Tree) (storage.FS, error) {
+	SetTraceProvider("http://localhost:14268/api/traces")
 	err := tp.Setup(o.Owner)
 	if err != nil {
 		logger.New().Error().Err(err).
@@ -119,6 +126,7 @@ func New(o *options.Options, lu *Lookup, p PermissionsChecker, tp Tree) (storage
 		lu:           lu,
 		o:            o,
 		p:            p,
+		tprov:        prov,
 		chunkHandler: chunking.NewChunkHandler(filepath.Join(o.Root, "uploads")),
 	}, nil
 }
@@ -427,6 +435,24 @@ func (fs *Decomposedfs) GetMD(ctx context.Context, ref *provider.Reference, mdKe
 	return node.AsResourceInfo(ctx, &rp, mdKeys, utils.IsRelativeReference(ref))
 }
 
+var prov = trace.NewNoopTracerProvider()
+
+// SetTraceProvider sets the TracerProvider at a package level.
+func SetTraceProvider(url string) {
+	exp, err := jaeger.New(jaeger.WithCollectorEndpoint(jaeger.WithEndpoint(url)))
+	if err != nil {
+		panic(err)
+	}
+
+	prov = sdktrace.NewTracerProvider(
+		sdktrace.WithBatcher(exp),
+		sdktrace.WithResource(resource.NewWithAttributes(
+			semconv.SchemaURL,
+			semconv.ServiceNameKey.String("decomposedfs"),
+		)),
+	)
+}
+
 // ListFolder returns a list of resources in the specified folder
 func (fs *Decomposedfs) ListFolder(ctx context.Context, ref *provider.Reference, mdKeys []string) (finfos []*provider.ResourceInfo, err error) {
 	var n *node.Node
@@ -434,6 +460,9 @@ func (fs *Decomposedfs) ListFolder(ctx context.Context, ref *provider.Reference,
 		return
 	}
 
+	ctx, span := fs.tprov.Tracer("decomposedfs").Start(ctx, "ListFolder")
+	defer span.End()
+
 	if !n.Exists {
 		err = errtypes.NotFound(filepath.Join(n.ParentID, n.Name))
 		return

From 495d64cfc6ced6c72d6dd98af2bda17761d0bf20 Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Mon, 16 Aug 2021 16:31:08 +0200
Subject: [PATCH 11/14] traces: use the reva tracer as TraceProvider

---
 cmd/revad/runtime/runtime.go                  | 68 +------------------
 .../utils/decomposedfs/decomposedfs.go        | 27 +-------
 2 files changed, 5 insertions(+), 90 deletions(-)

diff --git a/cmd/revad/runtime/runtime.go b/cmd/revad/runtime/runtime.go
index 0d27376075..bac257454b 100644
--- a/cmd/revad/runtime/runtime.go
+++ b/cmd/revad/runtime/runtime.go
@@ -28,7 +28,6 @@ import (
 	"strconv"
 	"strings"
 
-	"contrib.go.opencensus.io/exporter/jaeger"
 	"github.com/cs3org/reva/cmd/revad/internal/grace"
 	"github.com/cs3org/reva/pkg/logger"
 	"github.com/cs3org/reva/pkg/registry/memory"
@@ -40,15 +39,6 @@ import (
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
 	"github.com/rs/zerolog"
-	"go.opencensus.io/plugin/ocgrpc"
-	"go.opencensus.io/plugin/ochttp"
-	"go.opencensus.io/stats/view"
-	"go.opencensus.io/trace"
-)
-
-const (
-	tracingOC = "opencensus"
-	tracingOT = "opentelemetry"
 )
 
 // Run runs a reva server with the given config file and pid file.
@@ -97,9 +87,8 @@ func run(mainConf map[string]interface{}, coreConf *coreConf, logger *zerolog.Lo
 	host, _ := os.Hostname()
 	logger.Info().Msgf("host info: %s", host)
 
-	// initRegistry()
 	if coreConf.TracingEnabled {
-		initTracing(coreConf, logger)
+		initTracing(coreConf)
 	}
 	initCPUCount(coreConf, logger)
 
@@ -159,53 +148,8 @@ func initServers(mainConf map[string]interface{}, log *zerolog.Logger) map[strin
 	return servers
 }
 
-func initTracing(conf *coreConf, log *zerolog.Logger) {
-	switch {
-	case conf.TracingService == tracingOC:
-		err := setupOpenCensus(conf)
-		if err != nil {
-			log.Error().Err(err).Msg("error configuring open census stats and tracing")
-			os.Exit(1)
-		}
-	case conf.TracingService == tracingOT:
-		rtrace.SetTraceProvider(conf.TracingCollector)
-	default:
-		log.Error().Msg(fmt.Sprintf("error configuring telemetry. unknown type `%s`", conf.TracingService))
-		os.Exit(1)
-	}
-}
-
-func setupOpenCensus(conf *coreConf) error {
-	if err := view.Register(ochttp.DefaultServerViews...); err != nil {
-		return err
-	}
-
-	if err := view.Register(ocgrpc.DefaultServerViews...); err != nil {
-		return err
-	}
-
-	if !conf.TracingEnabled {
-		return nil
-	}
-
-	if conf.TracingServiceName == "" {
-		conf.TracingServiceName = "revad"
-	}
-
-	je, err := jaeger.NewExporter(jaeger.Options{
-		AgentEndpoint:     conf.TracingEndpoint,
-		CollectorEndpoint: conf.TracingCollector,
-		ServiceName:       conf.TracingServiceName,
-	})
-
-	if err != nil {
-		return err
-	}
-
-	// register it as a trace exporter
-	trace.RegisterExporter(je)
-	trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()})
-	return nil
+func initTracing(conf *coreConf) {
+	rtrace.SetTraceProvider(conf.TracingCollector)
 }
 
 func initCPUCount(conf *coreConf, log *zerolog.Logger) {
@@ -367,12 +311,6 @@ func parseCoreConfOrDie(v interface{}) *coreConf {
 		os.Exit(1)
 	}
 
-	// ensure backwards compatibility, if tracing is enabled default to opencensus as there are parts of the code
-	// that rely on a configured opencensus singleton.
-	if c.TracingEnabled && c.TracingService == "" {
-		c.TracingService = tracingOC
-	}
-
 	return c
 }
 
diff --git a/pkg/storage/utils/decomposedfs/decomposedfs.go b/pkg/storage/utils/decomposedfs/decomposedfs.go
index bfa698c23a..51c6ee7de1 100644
--- a/pkg/storage/utils/decomposedfs/decomposedfs.go
+++ b/pkg/storage/utils/decomposedfs/decomposedfs.go
@@ -47,13 +47,10 @@ import (
 	"github.com/cs3org/reva/pkg/storage/utils/decomposedfs/tree"
 	"github.com/cs3org/reva/pkg/storage/utils/decomposedfs/xattrs"
 	"github.com/cs3org/reva/pkg/storage/utils/templates"
+	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/pkg/errors"
 	"github.com/pkg/xattr"
-	"go.opentelemetry.io/otel/exporters/jaeger"
-	"go.opentelemetry.io/otel/sdk/resource"
-	sdktrace "go.opentelemetry.io/otel/sdk/trace"
-	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
 	"go.opentelemetry.io/otel/trace"
 )
 
@@ -113,7 +110,6 @@ func NewDefault(m map[string]interface{}, bs tree.Blobstore) (storage.FS, error)
 // New returns an implementation of the storage.FS interface that talks to
 // a local filesystem.
 func New(o *options.Options, lu *Lookup, p PermissionsChecker, tp Tree) (storage.FS, error) {
-	SetTraceProvider("http://localhost:14268/api/traces")
 	err := tp.Setup(o.Owner)
 	if err != nil {
 		logger.New().Error().Err(err).
@@ -126,7 +122,6 @@ func New(o *options.Options, lu *Lookup, p PermissionsChecker, tp Tree) (storage
 		lu:           lu,
 		o:            o,
 		p:            p,
-		tprov:        prov,
 		chunkHandler: chunking.NewChunkHandler(filepath.Join(o.Root, "uploads")),
 	}, nil
 }
@@ -435,24 +430,6 @@ func (fs *Decomposedfs) GetMD(ctx context.Context, ref *provider.Reference, mdKe
 	return node.AsResourceInfo(ctx, &rp, mdKeys, utils.IsRelativeReference(ref))
 }
 
-var prov = trace.NewNoopTracerProvider()
-
-// SetTraceProvider sets the TracerProvider at a package level.
-func SetTraceProvider(url string) {
-	exp, err := jaeger.New(jaeger.WithCollectorEndpoint(jaeger.WithEndpoint(url)))
-	if err != nil {
-		panic(err)
-	}
-
-	prov = sdktrace.NewTracerProvider(
-		sdktrace.WithBatcher(exp),
-		sdktrace.WithResource(resource.NewWithAttributes(
-			semconv.SchemaURL,
-			semconv.ServiceNameKey.String("decomposedfs"),
-		)),
-	)
-}
-
 // ListFolder returns a list of resources in the specified folder
 func (fs *Decomposedfs) ListFolder(ctx context.Context, ref *provider.Reference, mdKeys []string) (finfos []*provider.ResourceInfo, err error) {
 	var n *node.Node
@@ -460,7 +437,7 @@ func (fs *Decomposedfs) ListFolder(ctx context.Context, ref *provider.Reference,
 		return
 	}
 
-	ctx, span := fs.tprov.Tracer("decomposedfs").Start(ctx, "ListFolder")
+	ctx, span := rtrace.Provider.Tracer("decomposedfs").Start(ctx, "ListFolder")
 	defer span.End()
 
 	if !n.Exists {

From 3e9f5adfdda51313c4a7dbdd16424d13123e91e4 Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Mon, 16 Aug 2021 17:18:30 +0200
Subject: [PATCH 12/14] traceds: reduce redundancy, use rtrace.Propagator

---
 pkg/rgrpc/todo/pool/pool.go | 7 +------
 pkg/rhttp/rhttp.go          | 8 --------
 2 files changed, 1 insertion(+), 14 deletions(-)

diff --git a/pkg/rgrpc/todo/pool/pool.go b/pkg/rgrpc/todo/pool/pool.go
index 3ab9535bc9..d2d54cb599 100644
--- a/pkg/rgrpc/todo/pool/pool.go
+++ b/pkg/rgrpc/todo/pool/pool.go
@@ -21,8 +21,6 @@ package pool
 import (
 	"sync"
 
-	"go.opentelemetry.io/otel/propagation"
-
 	appprovider "github.com/cs3org/go-cs3apis/cs3/app/provider/v1beta1"
 	appregistry "github.com/cs3org/go-cs3apis/cs3/app/registry/v1beta1"
 	applicationauth "github.com/cs3org/go-cs3apis/cs3/auth/applications/v1beta1"
@@ -42,7 +40,6 @@ import (
 	storageregistry "github.com/cs3org/go-cs3apis/cs3/storage/registry/v1beta1"
 	datatx "github.com/cs3org/go-cs3apis/cs3/tx/v1beta1"
 	rtrace "github.com/cs3org/reva/pkg/trace"
-	"go.opencensus.io/plugin/ocgrpc"
 	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 	"google.golang.org/grpc"
 )
@@ -91,18 +88,16 @@ func NewConn(endpoint string) (*grpc.ClientConn, error) {
 	conn, err := grpc.Dial(
 		endpoint,
 		grpc.WithInsecure(),
-		grpc.WithStatsHandler(&ocgrpc.ClientHandler{}),
 		grpc.WithDefaultCallOptions(
 			grpc.MaxCallRecvMsgSize(maxCallRecvMsgSize),
 		),
-		// TODO(refs) add this DialOption only if tracing is enabled. Unaware of the drawbacks.
 		grpc.WithUnaryInterceptor(
 			otelgrpc.UnaryClientInterceptor(
 				otelgrpc.WithTracerProvider(
 					rtrace.Provider,
 				),
 				otelgrpc.WithPropagators(
-					propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}),
+					rtrace.Propagator,
 				),
 			),
 		),
diff --git a/pkg/rhttp/rhttp.go b/pkg/rhttp/rhttp.go
index 5e64d172a0..e3a4c12680 100644
--- a/pkg/rhttp/rhttp.go
+++ b/pkg/rhttp/rhttp.go
@@ -37,7 +37,6 @@ import (
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
 	"github.com/rs/zerolog"
-	"go.opencensus.io/plugin/ochttp"
 	"go.opentelemetry.io/otel/propagation"
 )
 
@@ -290,13 +289,6 @@ func (s *Server) getHandler() (http.Handler, error) {
 		handler = triple.Middleware(traceHandler(triple.Name, handler))
 	}
 
-	// use opencensus handler to trace endpoints.
-	// TODO(labkode): enable also opencensus telemetry.
-	handler = &ochttp.Handler{
-		Handler: handler,
-		//IsPublicEndpoint: true,
-	}
-
 	return handler, nil
 }
 

From e4597baeb703e337cac94dccc38f0a8cb98cb10a Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Mon, 16 Aug 2021 17:26:01 +0200
Subject: [PATCH 13/14] traces: add stream interceptors to rpc connection
 options

---
 pkg/rgrpc/todo/pool/pool.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/pkg/rgrpc/todo/pool/pool.go b/pkg/rgrpc/todo/pool/pool.go
index d2d54cb599..550d7d7499 100644
--- a/pkg/rgrpc/todo/pool/pool.go
+++ b/pkg/rgrpc/todo/pool/pool.go
@@ -91,6 +91,14 @@ func NewConn(endpoint string) (*grpc.ClientConn, error) {
 		grpc.WithDefaultCallOptions(
 			grpc.MaxCallRecvMsgSize(maxCallRecvMsgSize),
 		),
+		grpc.WithStreamInterceptor(otelgrpc.StreamClientInterceptor(
+			otelgrpc.WithTracerProvider(
+				rtrace.Provider,
+			),
+			otelgrpc.WithPropagators(
+				rtrace.Propagator,
+			),
+		)),
 		grpc.WithUnaryInterceptor(
 			otelgrpc.UnaryClientInterceptor(
 				otelgrpc.WithTracerProvider(

From 6b3a5e2f70e7976b780580b6cc3ed9cc7bf9289e Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Mon, 16 Aug 2021 19:47:46 +0200
Subject: [PATCH 14/14] traces: remove unused attribute tprov

---
 pkg/storage/utils/decomposedfs/decomposedfs.go | 2 --
 1 file changed, 2 deletions(-)

diff --git a/pkg/storage/utils/decomposedfs/decomposedfs.go b/pkg/storage/utils/decomposedfs/decomposedfs.go
index 51c6ee7de1..7dacfeaad7 100644
--- a/pkg/storage/utils/decomposedfs/decomposedfs.go
+++ b/pkg/storage/utils/decomposedfs/decomposedfs.go
@@ -51,7 +51,6 @@ import (
 	"github.com/cs3org/reva/pkg/utils"
 	"github.com/pkg/errors"
 	"github.com/pkg/xattr"
-	"go.opentelemetry.io/otel/trace"
 )
 
 // PermissionsChecker defines an interface for checking permissions on a Node
@@ -87,7 +86,6 @@ type Decomposedfs struct {
 	tp           Tree
 	o            *options.Options
 	p            PermissionsChecker
-	tprov        trace.TracerProvider
 	chunkHandler *chunking.ChunkHandler
 }