Expose tunning options via expvar

cmd/agent/app/agent_test.go

@@ -27,6 +27,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/uber/jaeger-lib/metrics"
+	"github.com/uber/jaeger-lib/metrics/fork"
 	"go.uber.org/zap"
 
 	jmetrics "github.com/jaegertracing/jaeger/pkg/metrics"
@@ -100,7 +101,8 @@ func withRunningAgent(t *testing.T, testcase func(string, chan error)) {
 	}
 	logger, logBuf := testutils.NewLogger()
 	mBldr := &jmetrics.Builder{HTTPRoute: "/metrics", Backend: "prometheus"}
-	mFactory, err := mBldr.CreateMetricsFactory("jaeger")
+	metricsFactory, err := mBldr.CreateMetricsFactory("jaeger")
+	mFactory := fork.New("internal", metrics.NullFactory, metricsFactory)
 	require.NoError(t, err)
 	agent, err := cfg.CreateAgent(fakeCollectorProxy{}, logger, mFactory)
 	require.NoError(t, err)
@@ -162,7 +164,8 @@ func TestStartStopRace(t *testing.T) {
 	}
 	logger, logBuf := testutils.NewLogger()
 	mBldr := &jmetrics.Builder{HTTPRoute: "/metrics", Backend: "prometheus"}
-	mFactory, err := mBldr.CreateMetricsFactory("jaeger")
+	metricsFactory, err := mBldr.CreateMetricsFactory("jaeger")
+	mFactory := fork.New("internal", metrics.NullFactory, metricsFactory)
 	require.NoError(t, err)
 	agent, err := cfg.CreateAgent(fakeCollectorProxy{}, logger, mFactory)
 	require.NoError(t, err)

cmd/agent/app/builder.go

@@ -112,6 +112,8 @@ func (b *Builder) CreateAgent(primaryProxy CollectorProxy, logger *zap.Logger, m
 		return nil, fmt.Errorf("cannot create processors: %w", err)
 	}
 	server := b.HTTPServer.getHTTPServer(primaryProxy.GetManager(), mFactory)
+	b.publishOpts(mFactory)
+
 	return NewAgent(processors, server, logger), nil
 }
 
@@ -127,6 +129,19 @@ func (b *Builder) getReporter(primaryProxy CollectorProxy) reporter.Reporter {
 	return reporter.NewMultiReporter(rep...)
 }
 
+func (b *Builder) publishOpts(mFactory metrics.Factory) {
+	internalFactory := mFactory.Namespace(metrics.NSOptions{Name: "internal"})
+	for _, p := range b.Processors {
+		prefix := fmt.Sprintf(processorPrefixFmt, p.Model, p.Protocol)
+		internalFactory.Gauge(metrics.Options{Name: prefix + suffixServerMaxPacketSize}).
+			Update(int64(p.Server.MaxPacketSize))
+		internalFactory.Gauge(metrics.Options{Name: prefix + suffixServerQueueSize}).
+			Update(int64(p.Server.QueueSize))
+		internalFactory.Gauge(metrics.Options{Name: prefix + suffixWorkers}).
+			Update(int64(p.Workers))
+	}
+}
+
 func (b *Builder) getProcessors(rep reporter.Reporter, mFactory metrics.Factory, logger *zap.Logger) ([]processors.Processor, error) {
 	retMe := make([]processors.Processor, len(b.Processors))
 	for idx, cfg := range b.Processors {

cmd/agent/app/builder_test.go

@@ -29,6 +29,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/uber/jaeger-lib/metrics"
+	"github.com/uber/jaeger-lib/metrics/fork"
 	"github.com/uber/jaeger-lib/metrics/metricstest"
 	"go.uber.org/zap"
 	yaml "gopkg.in/yaml.v2"
@@ -277,3 +278,42 @@ func TestCreateCollectorProxy_UnknownReporter(t *testing.T) {
 	assert.Nil(t, proxy)
 	assert.EqualError(t, err, "unknown reporter type ")
 }
+
+func TestPublishOpts(t *testing.T) {
+	v := viper.New()
+	cfg := &Builder{}
+	command := cobra.Command{}
+	flags := &flag.FlagSet{}
+	AddFlags(flags)
+	command.PersistentFlags().AddGoFlagSet(flags)
+	v.BindPFlags(command.PersistentFlags())
+	err := command.ParseFlags([]string{
+		"--http-server.host-port=:8080",
+		"--processor.jaeger-binary.server-host-port=:1111",
+		"--processor.jaeger-binary.server-max-packet-size=4242",
+		"--processor.jaeger-binary.server-queue-size=24",
+		"--processor.jaeger-binary.workers=42",
+	})
+	require.NoError(t, err)
+	cfg.InitFromViper(v)
+
+	baseMetrics := metricstest.NewFactory(time.Second)
+	forkFactory := metricstest.NewFactory(time.Second)
+	metricsFactory := fork.New("internal", forkFactory, baseMetrics)
+	agent, err := cfg.CreateAgent(fakeCollectorProxy{}, zap.NewNop(), metricsFactory)
+	assert.NoError(t, err)
+	assert.NotNil(t, agent)
+
+	forkFactory.AssertGaugeMetrics(t, metricstest.ExpectedMetric{
+		Name:  "internal.processor.jaeger-binary.server-max-packet-size",
+		Value: 4242,
+	})
+	forkFactory.AssertGaugeMetrics(t, metricstest.ExpectedMetric{
+		Name:  "internal.processor.jaeger-binary.server-queue-size",
+		Value: 24,
+	})
+	forkFactory.AssertGaugeMetrics(t, metricstest.ExpectedMetric{
+		Name:  "internal.processor.jaeger-binary.workers",
+		Value: 42,
+	})
+}

cmd/agent/app/flags.go

@@ -31,6 +31,9 @@ const (
 	suffixServerMaxPacketSize    = "server-max-packet-size"
 	suffixServerSocketBufferSize = "server-socket-buffer-size"
 	suffixServerHostPort         = "server-host-port"
+
+	processorPrefixFmt = "processor.%s-%s."
+
 	// HTTPServerHostPort is the flag for HTTP endpoint
 	HTTPServerHostPort = "http-server.host-port"
 )
@@ -48,7 +51,7 @@ var defaultProcessors = []struct {
 // AddFlags adds flags for Builder.
 func AddFlags(flags *flag.FlagSet) {
 	for _, p := range defaultProcessors {
-		prefix := fmt.Sprintf("processor.%s-%s.", p.model, p.protocol)
+		prefix := fmt.Sprintf(processorPrefixFmt, p.model, p.protocol)
 		flags.Int(prefix+suffixWorkers, defaultServerWorkers, "how many workers the processor should run")
 		flags.Int(prefix+suffixServerQueueSize, defaultQueueSize, "length of the queue for the UDP server")
 		flags.Int(prefix+suffixServerMaxPacketSize, defaultMaxPacketSize, "max packet size for the UDP server")
@@ -69,7 +72,7 @@ func AddOTELFlags(flags *flag.FlagSet) {
 // InitFromViper initializes Builder with properties retrieved from Viper.
 func (b *Builder) InitFromViper(v *viper.Viper) *Builder {
 	for _, processor := range defaultProcessors {
-		prefix := fmt.Sprintf("processor.%s-%s.", processor.model, processor.protocol)
+		prefix := fmt.Sprintf(processorPrefixFmt, processor.model, processor.protocol)
 		p := &ProcessorConfiguration{Model: processor.model, Protocol: processor.protocol}
 		p.Workers = v.GetInt(prefix + suffixWorkers)
 		p.Server.QueueSize = v.GetInt(prefix + suffixServerQueueSize)

cmd/agent/main.go

@@ -22,6 +22,8 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"github.com/uber/jaeger-lib/metrics"
+	jexpvar "github.com/uber/jaeger-lib/metrics/expvar"
+	"github.com/uber/jaeger-lib/metrics/fork"
 	_ "go.uber.org/automaxprocs"
 	"go.uber.org/zap"
 
@@ -49,9 +51,12 @@ func main() {
 				return err
 			}
 			logger := svc.Logger // shortcut
-			mFactory := svc.MetricsFactory.
+			baseFactory := svc.MetricsFactory.
 				Namespace(metrics.NSOptions{Name: "jaeger"}).
 				Namespace(metrics.NSOptions{Name: "agent"})
+			mFactory := fork.New("internal",
+				jexpvar.NewFactory(10), // backend for internal opts
+				baseFactory)
 
 			rOpts := new(reporter.Options).InitFromViper(v, logger)
 			grpcBuilder := grpc.NewConnBuilder().InitFromViper(v)
@@ -79,6 +84,7 @@ func main() {
 			if err := agent.Run(); err != nil {
 				return fmt.Errorf("failed to run the agent: %w", err)
 			}
+
 			svc.RunAndThen(func() {
 				agent.Stop()
 				cp.Close()

cmd/all-in-one/main.go

@@ -27,6 +27,8 @@ import (
 	jaegerClientConfig "github.com/uber/jaeger-client-go/config"
 	jaegerClientZapLog "github.com/uber/jaeger-client-go/log/zap"
 	"github.com/uber/jaeger-lib/metrics"
+	jexpvar "github.com/uber/jaeger-lib/metrics/expvar"
+	"github.com/uber/jaeger-lib/metrics/fork"
 	_ "go.uber.org/automaxprocs"
 	"go.uber.org/zap"
 
@@ -81,7 +83,10 @@ by default uses only in-memory database.`,
 			}
 			logger := svc.Logger                     // shortcut
 			rootMetricsFactory := svc.MetricsFactory // shortcut
-			metricsFactory := rootMetricsFactory.Namespace(metrics.NSOptions{Name: "jaeger"})
+			metricsFactory := fork.New("internal",
+				jexpvar.NewFactory(10), // backend for internal opts
+				rootMetricsFactory.Namespace(metrics.NSOptions{Name: "jaeger"}))
+
 			tracerCloser := initTracer(rootMetricsFactory, svc.Logger)
 
 			storageFactory.InitFromViper(v)

cmd/collector/app/builder_flags.go

@@ -116,5 +116,6 @@ func (cOpts *CollectorOptions) InitFromViper(v *viper.Viper) *CollectorOptions {
 	cOpts.CollectorZipkinAllowedOrigins = v.GetString(collectorZipkinAllowedOrigins)
 	cOpts.CollectorZipkinAllowedHeaders = v.GetString(collectorZipkinAllowedHeaders)
 	cOpts.TLS = tlsFlagsConfig.InitFromViper(v)
+
 	return cOpts
 }

cmd/collector/app/collector.go

@@ -122,10 +122,17 @@ func (c *Collector) Start(builderOpts *CollectorOptions) error {
 	} else {
 		c.zkServer = zkServer
 	}
+	c.publishOpts(builderOpts)
 
 	return nil
 }
 
+func (c *Collector) publishOpts(cOpts *CollectorOptions) {
+	internalFactory := c.metricsFactory.Namespace(metrics.NSOptions{Name: "internal"})
+	internalFactory.Gauge(metrics.Options{Name: collectorNumWorkers}).Update(int64(cOpts.NumWorkers))
+	internalFactory.Gauge(metrics.Options{Name: collectorQueueSize}).Update(int64(cOpts.QueueSize))
+}
+
 // Close the component and all its underlying dependencies
 func (c *Collector) Close() error {
 	// gRPC server

cmd/collector/app/collector_test.go

@@ -21,6 +21,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/uber/jaeger-lib/metrics/fork"
 	"github.com/uber/jaeger-lib/metrics/metricstest"
 	"go.uber.org/zap"
 
@@ -61,3 +62,39 @@ type mockStrategyStore struct {
 func (m *mockStrategyStore) GetSamplingStrategy(_ context.Context, serviceName string) (*sampling.SamplingStrategyResponse, error) {
 	return &sampling.SamplingStrategyResponse{}, nil
 }
+
+func TestCollector_PublishOpts(t *testing.T) {
+	// prepare
+	hc := healthcheck.New()
+	logger := zap.NewNop()
+	baseMetrics := metricstest.NewFactory(time.Second)
+	forkFactory := metricstest.NewFactory(time.Second)
+	metricsFactory := fork.New("internal", forkFactory, baseMetrics)
+	spanWriter := &fakeSpanWriter{}
+	strategyStore := &mockStrategyStore{}
+
+	c := New(&CollectorParams{
+		ServiceName:    "collector",
+		Logger:         logger,
+		MetricsFactory: metricsFactory,
+		SpanWriter:     spanWriter,
+		StrategyStore:  strategyStore,
+		HealthCheck:    hc,
+	})
+	collectorOpts := &CollectorOptions{
+		NumWorkers: 24,
+		QueueSize:  42,
+	}
+
+	c.Start(collectorOpts)
+	defer c.Close()
+
+	forkFactory.AssertGaugeMetrics(t, metricstest.ExpectedMetric{
+		Name:  "internal.collector.num-workers",
+		Value: 24,
+	})
+	forkFactory.AssertGaugeMetrics(t, metricstest.ExpectedMetric{
+		Name:  "internal.collector.queue-size",
+		Value: 42,
+	})
+}

cmd/collector/main.go

@@ -24,6 +24,8 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"github.com/uber/jaeger-lib/metrics"
+	jexpvar "github.com/uber/jaeger-lib/metrics/expvar"
+	"github.com/uber/jaeger-lib/metrics/fork"
 	_ "go.uber.org/automaxprocs"
 	"go.uber.org/zap"
 
@@ -63,7 +65,9 @@ func main() {
 			}
 			logger := svc.Logger // shortcut
 			baseFactory := svc.MetricsFactory.Namespace(metrics.NSOptions{Name: "jaeger"})
-			metricsFactory := baseFactory.Namespace(metrics.NSOptions{Name: "collector"})
+			metricsFactory := fork.New("internal",
+				jexpvar.NewFactory(10), // backend for internal opts
+				baseFactory.Namespace(metrics.NSOptions{Name: "collector"}))
 
 			storageFactory.InitFromViper(v)
 			if err := storageFactory.Initialize(baseFactory, logger); err != nil {

cmd/flags/service.go

@@ -15,6 +15,7 @@
 package flags
 
 import (
+	"expvar"
 	"flag"
 	"fmt"
 	"os"
@@ -116,6 +117,13 @@ func (s *Service) Start(v *viper.Viper) error {
 		s.Logger.Info("Mounting metrics handler on admin server", zap.String("route", route))
 		s.Admin.Handle(route, h)
 	}
+
+	// Mount expvar routes on different backends
+	if metricsBuilder.Backend != "expvar" {
+		s.Logger.Info("Mounting expvar handler on admin server", zap.String("route", "/debug/vars"))
+		s.Admin.Handle("/debug/vars", expvar.Handler())
+	}
+
 	if err := s.Admin.Serve(); err != nil {
 		return fmt.Errorf("cannot start the admin server: %w", err)
 	}

cmd/opentelemetry/go.mod

@@ -15,7 +15,7 @@ require (
 	github.com/spf13/viper v1.7.1
 	github.com/stretchr/testify v1.6.1
 	github.com/uber/jaeger-client-go v2.25.0+incompatible
-	github.com/uber/jaeger-lib v2.2.0+incompatible
+	github.com/uber/jaeger-lib v2.3.1-0.20200925164221-2cac3b34a519+incompatible
 	go.opencensus.io v0.22.4
 	go.opentelemetry.io/collector v0.10.1-0.20200917170114-639b9a80ed46
 	go.uber.org/zap v1.16.0

cmd/opentelemetry/go.sum

@@ -76,6 +76,7 @@ github.com/DataDog/zstd v1.3.6-0.20190409195224-796139022798/go.mod h1:1jcaCB/uf
 github.com/DataDog/zstd v1.4.4/go.mod h1:1jcaCB/ufaK+sKp1NBhlGmpz41jOoPQ35bpF36t7BBo=
 github.com/Djarvur/go-err113 v0.0.0-20200511133814-5174e21577d5 h1:XTrzB+F8+SpRmbhAH8HLxhiiG6nYNwaBZjrFps1oWEk=
 github.com/Djarvur/go-err113 v0.0.0-20200511133814-5174e21577d5/go.mod h1:4UJr5HIiMZrwgkSPdsjy2uOQExX/WEILpIrO9UPGuXs=
+github.com/HdrHistogram/hdrhistogram-go v0.9.0/go.mod h1:nxrse8/Tzg2tg3DZcZjm6qEclQKK70g0KxO61gFFZD4=
 github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible/go.mod h1:r7JcOSlj0wfOMncg0iLm8Leh48TZaKVeNIfJntJ2wa0=
 github.com/Masterminds/semver v1.5.0 h1:H65muMkzWKEuNDnfl9d70GUjFniHKHRbFPGBuZ3QEww=
 github.com/Masterminds/semver v1.5.0/go.mod h1:MB6lktGJrhw8PrUyiEoblNEGEQ+RzHPF078ddwwvV3Y=
@@ -1109,6 +1110,8 @@ github.com/uber/jaeger-client-go v2.25.0+incompatible h1:IxcNZ7WRY1Y3G4poYlx24sz
 github.com/uber/jaeger-client-go v2.25.0+incompatible/go.mod h1:WVhlPFC8FDjOFMMWRy2pZqQJSXxYSwNYOkTr/Z6d3Kk=
 github.com/uber/jaeger-lib v2.2.0+incompatible h1:MxZXOiR2JuoANZ3J6DE/U0kSFv/eJ/GfSYVCjK7dyaw=
 github.com/uber/jaeger-lib v2.2.0+incompatible/go.mod h1:ComeNDZlWwrWnDv8aPp0Ba6+uUTzImX/AauajbLI56U=
+github.com/uber/jaeger-lib v2.3.1-0.20200925164221-2cac3b34a519+incompatible h1:pif0W8e7IYk2xPZ/KYV8kqDP9aKsUJ/isUON9dDXkVE=
+github.com/uber/jaeger-lib v2.3.1-0.20200925164221-2cac3b34a519+incompatible/go.mod h1:ComeNDZlWwrWnDv8aPp0Ba6+uUTzImX/AauajbLI56U=
 github.com/ugorji/go v1.1.4/go.mod h1:uQMGLiO92mf5W77hV/PUCpI3pbzQx3CRekS0kk+RGrc=
 github.com/ultraware/funlen v0.0.3 h1:5ylVWm8wsNwH5aWo9438pwvsK0QiqVuUrt9bn7S/iLA=
 github.com/ultraware/funlen v0.0.3/go.mod h1:Dp4UiAus7Wdb9KUZsYWZEWiRzGuM2kXM1lPbfaF6xhA=

go.mod

@@ -5,6 +5,7 @@ go 1.14
 require (
 	github.com/AndreasBriese/bbloom v0.0.0-20190825152654-46b345b51c96 // indirect
 	github.com/DataDog/zstd v1.4.4 // indirect
+	github.com/HdrHistogram/hdrhistogram-go v0.9.0 // indirect
 	github.com/Shopify/sarama v1.22.2-0.20190604114437-cd910a683f9f
 	github.com/apache/thrift v0.13.0
 	github.com/bsm/sarama-cluster v2.1.13+incompatible
@@ -66,7 +67,7 @@ require (
 	github.com/spf13/viper v1.6.2
 	github.com/stretchr/testify v1.5.1
 	github.com/uber/jaeger-client-go v2.23.1+incompatible
-	github.com/uber/jaeger-lib v2.2.0+incompatible
+	github.com/uber/jaeger-lib v2.4.0+incompatible
 	github.com/vektra/mockery v0.0.0-20181123154057-e78b021dcbb5
 	github.com/wadey/gocovmerge v0.0.0-20160331181800-b5bfa59ec0ad
 	go.mongodb.org/mongo-driver v1.3.2 // indirect

go.sum

@@ -7,6 +7,8 @@ github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03
 github.com/DataDog/zstd v1.3.6-0.20190409195224-796139022798/go.mod h1:1jcaCB/ufaK+sKp1NBhlGmpz41jOoPQ35bpF36t7BBo=
 github.com/DataDog/zstd v1.4.4 h1:+IawcoXhCBylN7ccwdwf8LOH2jKq7NavGpEPanrlTzE=
 github.com/DataDog/zstd v1.4.4/go.mod h1:1jcaCB/ufaK+sKp1NBhlGmpz41jOoPQ35bpF36t7BBo=
+github.com/HdrHistogram/hdrhistogram-go v0.9.0 h1:dpujRju0R4M/QZzcnR1LH1qm+TVG3UzkWdp5tH1WMcg=
+github.com/HdrHistogram/hdrhistogram-go v0.9.0/go.mod h1:nxrse8/Tzg2tg3DZcZjm6qEclQKK70g0KxO61gFFZD4=
 github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible/go.mod h1:r7JcOSlj0wfOMncg0iLm8Leh48TZaKVeNIfJntJ2wa0=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/PuerkitoBio/purell v1.1.0/go.mod h1:c11w/QuzBsJSee3cPx9rAFu61PvFxuPbtSwDGJws/X0=
@@ -560,8 +562,8 @@ github.com/tmc/grpc-websocket-proxy v0.0.0-20170815181823-89b8d40f7ca8/go.mod h1
 github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
 github.com/uber/jaeger-client-go v2.23.1+incompatible h1:uArBYHQR0HqLFFAypI7RsWTzPSj/bDpmZZuQjMLSg1A=
 github.com/uber/jaeger-client-go v2.23.1+incompatible/go.mod h1:WVhlPFC8FDjOFMMWRy2pZqQJSXxYSwNYOkTr/Z6d3Kk=
-github.com/uber/jaeger-lib v2.2.0+incompatible h1:MxZXOiR2JuoANZ3J6DE/U0kSFv/eJ/GfSYVCjK7dyaw=
-github.com/uber/jaeger-lib v2.2.0+incompatible/go.mod h1:ComeNDZlWwrWnDv8aPp0Ba6+uUTzImX/AauajbLI56U=
+github.com/uber/jaeger-lib v2.4.0+incompatible h1:fY7QsGQWiCt8pajv4r7JEvmATdCVaWxXbjwyYwsNaLQ=
+github.com/uber/jaeger-lib v2.4.0+incompatible/go.mod h1:ComeNDZlWwrWnDv8aPp0Ba6+uUTzImX/AauajbLI56U=
 github.com/ugorji/go v1.1.4/go.mod h1:uQMGLiO92mf5W77hV/PUCpI3pbzQx3CRekS0kk+RGrc=
 github.com/urfave/cli v1.20.0/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
 github.com/urfave/cli v1.22.1/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtXRu0=

plugin/storage/factory.go

@@ -46,6 +46,7 @@ const (
 	badgerStorageType        = "badger"
 	downsamplingRatio        = "downsampling.ratio"
 	downsamplingHashSalt     = "downsampling.hashsalt"
+	spanStorageType          = "span-storage-type"
 
 	// defaultDownsamplingRatio is the default downsampling ratio.
 	defaultDownsamplingRatio = 1.0
@@ -111,6 +112,8 @@ func (f *Factory) Initialize(metricsFactory metrics.Factory, logger *zap.Logger)
 			return err
 		}
 	}
+	f.publishOpts()
+
 	return nil
 }
 
@@ -249,3 +252,11 @@ func (f *Factory) Close() error {
 	}
 	return multierror.Wrap(errs)
 }
+
+func (f *Factory) publishOpts() {
+	internalFactory := f.metricsFactory.Namespace(metrics.NSOptions{Name: "internal"})
+	internalFactory.Gauge(metrics.Options{Name: downsamplingRatio}).
+		Update(int64(f.FactoryConfig.DownsamplingRatio))
+	internalFactory.Gauge(metrics.Options{Name: spanStorageType + "-" + f.SpanReaderType}).
+		Update(1)
+}