Bump github.com/uber/jaeger-client-go

Bumps [github.com/uber/jaeger-client-go](https://github.com/uber/jaeger-client-go) from 2.19.0+incompatible to 2.20.0+incompatible.
- [Release notes](https://github.com/uber/jaeger-client-go/releases)
- [Changelog](https://github.com/jaegertracing/jaeger-client-go/blob/master/CHANGELOG.md)
- [Commits](https://github.com/uber/jaeger-client-go/compare/v2.19.0...v2.20.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

34 files changed, 1934 insertions, 444 deletions

diff --git a/vendor/github.com/uber/jaeger-client-go/.travis.yml b/vendor/github.com/uber/jaeger-client-go/.travis.yml
index 0d7bdd9ab..e81cc8805 100644
--- a/vendor/github.com/uber/jaeger-client-go/.travis.yml
+++ b/vendor/github.com/uber/jaeger-client-go/.travis.yml
@@ -7,21 +7,22 @@ dist: trusty
 
 matrix:
   include:
-  - go: 1.12.x
+  - go: 1.13.x
     env:
     - TESTS=true
     - USE_DEP=true
     - COVERAGE=true
-  - go: 1.12.x
+  - go: 1.13.x
     env:
     - USE_DEP=true
     - CROSSDOCK=true
-  - go: 1.12.x
+  - go: 1.13.x
     env:
     - TESTS=true
     - USE_DEP=false
     - USE_GLIDE=true
-  - go: 1.11.x
+  # test with previous version of Go
+  - go: 1.12.x
     env:
     - TESTS=true
     - USE_DEP=true
diff --git a/vendor/github.com/uber/jaeger-client-go/CHANGELOG.md b/vendor/github.com/uber/jaeger-client-go/CHANGELOG.md
index 31b22e40c..c4590bf93 100644
--- a/vendor/github.com/uber/jaeger-client-go/CHANGELOG.md
+++ b/vendor/github.com/uber/jaeger-client-go/CHANGELOG.md
@@ -1,6 +1,45 @@
 Changes by Version
 ==================
 
+2.20.0 (2019-11-06)
+-------------------
+
+## New Features
+
+- Allow all in-process spans of a trace to share sampling state (#443) -- Prithvi Raj
+
+  Sampling state is shared between all spans of the trace that are still in memory.
+  This allows implementation of delayed sampling decisions (see below).
+
+- Support delayed sampling decisions (#449) -- Yuri Shkuro
+
+  This is a large structural change to how the samplers work.
+  It allows some samplers to be executed multiple times on different
+  span events (like setting a tag) and make a positive sampling decision
+  later in the span life cycle, or even based on children spans.
+  See [README](./README.md#delayed-sampling) for more details.
+
+  There is a related minor change in behavior of the adaptive (per-operation) sampler,
+  which will no longer re-sample the trace when `span.SetOperation()` is called, i.e. the
+  operation used to make the sampling decision is always the one provided at span creation.
+
+- Add experimental tag matching sampler (#452) -- Yuri Shkuro
+
+  A sampler that can sample a trace based on a certain tag added to the root
+  span or one of its local (in-process) children. The sampler can be used with
+  another experimental `PrioritySampler` that allows multiple samplers to try
+  to make a sampling decision, in a certain priority order.
+
+- [log/zap] Report whether a trace was sampled (#445) -- Abhinav Gupta
+- Allow config.FromEnv() to enrich an existing config object (#436) -- Vineeth Reddy
+
+## Minor patches
+
+- Expose Sampler on Tracer and accept sampler options via Configuration (#460) -- Yuri Shkuro
+- Fix github.com/uber-go/atomic import (#464) -- Yuri Shkuro
+- Add nodejs to crossdock tests (#441) -- Bhavin Gandhi
+- Bump Go compiler version to 1.13 (#453) -- Yuri Shkuro
+
 2.19.0 (2019-09-23)
 -------------------
 
diff --git a/vendor/github.com/uber/jaeger-client-go/Gopkg.lock b/vendor/github.com/uber/jaeger-client-go/Gopkg.lock
index 1ed86f4a7..5a42ebf16 100644
--- a/vendor/github.com/uber/jaeger-client-go/Gopkg.lock
+++ b/vendor/github.com/uber/jaeger-client-go/Gopkg.lock
@@ -2,6 +2,14 @@
 
 
 [[projects]]
+  digest = "1:9f3b30d9f8e0d7040f729b82dcbc8f0dead820a133b3147ce355fc451f32d761"
+  name = "github.com/BurntSushi/toml"
+  packages = ["."]
+  pruneopts = "UT"
+  revision = "3012a1dbe2e4bd1391d42b32f0577cb7bbc7f005"
+  version = "v0.3.1"
+
+[[projects]]
   digest = "1:d6afaeed1502aa28e80a4ed0981d570ad91b2579193404256ce672ed0a609e0d"
   name = "github.com/beorn7/perks"
   packages = ["quantile"]
@@ -138,14 +146,6 @@
   version = "v1.4.0"
 
 [[projects]]
-  digest = "1:a5158647b553c61877aa9ae74f4015000294e47981e6b8b07525edcbb0747c81"
-  name = "github.com/uber-go/atomic"
-  packages = ["."]
-  pruneopts = "UT"
-  revision = "df976f2515e274675050de7b3f42545de80594fd"
-  version = "v1.4.0"
-
-[[projects]]
   digest = "1:0ec60ffd594af00ba1660bc746aa0e443d27dd4003dee55f9d08a0b4ff5431a3"
   name = "github.com/uber/jaeger-lib"
   packages = [
@@ -158,23 +158,31 @@
   version = "v2.2.0"
 
 [[projects]]
-  digest = "1:a5158647b553c61877aa9ae74f4015000294e47981e6b8b07525edcbb0747c81"
+  digest = "1:0bdcb0c740d79d400bd3f7946ac22a715c94db62b20bfd2e01cd50693aba0600"
   name = "go.uber.org/atomic"
   packages = ["."]
   pruneopts = "UT"
-  revision = "df976f2515e274675050de7b3f42545de80594fd"
-  version = "v1.4.0"
+  revision = "9dc4df04d0d1c39369750a9f6c32c39560672089"
+  version = "v1.5.0"
 
 [[projects]]
-  digest = "1:60bf2a5e347af463c42ed31a493d817f8a72f102543060ed992754e689805d1a"
+  digest = "1:002ebc50f3ef475ac325e1904be931d9dcba6dc6d73b5682afce0c63436e3902"
   name = "go.uber.org/multierr"
   packages = ["."]
   pruneopts = "UT"
-  revision = "3c4937480c32f4c13a875a1829af76c98ca3d40a"
-  version = "v1.1.0"
+  revision = "c3fc3d02ec864719d8e25be2d7dde1e35a36aa27"
+  version = "v1.3.0"
+
+[[projects]]
+  branch = "master"
+  digest = "1:3032e90a153750ea149f68bf081f97ca738f041fba45c41c80737f572ffdf2f4"
+  name = "go.uber.org/tools"
+  packages = ["update-license"]
+  pruneopts = "UT"
+  revision = "2cfd321de3ee5d5f8a5fda2521d1703478334d98"
 
 [[projects]]
-  digest = "1:676160e6a4722b08e0e26b11521d575c2cb2b6f0c679e1ee6178c5d8dee51e5e"
+  digest = "1:6be13632ab4bd5842a097abb3aabac045a8601e19a10da4239e7d8bd83d4b83c"
   name = "go.uber.org/zap"
   packages = [
     ".",
@@ -185,8 +193,19 @@
     "zapcore",
   ]
   pruneopts = "UT"
-  revision = "27376062155ad36be76b0f12cf1572a221d3a48c"
-  version = "v1.10.0"
+  revision = "a6015e13fab9b744d96085308ce4e8f11bad1996"
+  version = "v1.12.0"
+
+[[projects]]
+  branch = "master"
+  digest = "1:21d7bad9b7da270fd2d50aba8971a041bd691165c95096a2a4c68db823cbc86a"
+  name = "golang.org/x/lint"
+  packages = [
+    ".",
+    "golint",
+  ]
+  pruneopts = "UT"
+  revision = "16217165b5de779cb6a5e4fc81fa9c1166fda457"
 
 [[projects]]
   branch = "master"
@@ -197,23 +216,81 @@
     "context/ctxhttp",
   ]
   pruneopts = "UT"
-  revision = "aa69164e4478b84860dc6769c710c699c67058a3"
+  revision = "0deb6923b6d97481cb43bc1043fe5b72a0143032"
 
 [[projects]]
   branch = "master"
-  digest = "1:712252802d318c8107d8f2136b99aa10feb17eca715245ed915199fbfc260155"
+  digest = "1:5dfb17d45415b7b8927382f53955a66f55f9d9d11557aa82f7f481d642ab247a"
   name = "golang.org/x/sys"
   packages = ["windows"]
   pruneopts = "UT"
-  revision = "0a153f010e6963173baba2306531d173aa843137"
+  revision = "f43be2a4598cf3a47be9f94f0c28197ed9eae611"
+
+[[projects]]
+  branch = "master"
+  digest = "1:bae8b3bf837d9d7f601776f37f44e031d46943677beff8fb2eb9c7317d44de2f"
+  name = "golang.org/x/tools"
+  packages = [
+    "go/analysis",
+    "go/analysis/passes/inspect",
+    "go/ast/astutil",
+    "go/ast/inspector",
+    "go/buildutil",
+    "go/gcexportdata",
+    "go/internal/gcimporter",
+    "go/internal/packagesdriver",
+    "go/packages",
+    "go/types/objectpath",
+    "go/types/typeutil",
+    "internal/fastwalk",
+    "internal/gopathwalk",
+    "internal/semver",
+    "internal/span",
+  ]
+  pruneopts = "UT"
+  revision = "8dbcdeb83d3faec5315146800b375c4962a42fc6"
 
 [[projects]]
-  digest = "1:4d2e5a73dc1500038e504a8d78b986630e3626dc027bc030ba5c75da257cdb96"
+  digest = "1:59f10c1537d2199d9115d946927fe31165959a95190849c82ff11e05803528b0"
   name = "gopkg.in/yaml.v2"
   packages = ["."]
   pruneopts = "UT"
-  revision = "51d6538a90f86fe93ac480b35f37b2be17fef232"
-  version = "v2.2.2"
+  revision = "f221b8435cfb71e54062f6c6e99e9ade30b124d5"
+  version = "v2.2.4"
+
+[[projects]]
+  digest = "1:131158a88aad1f94854d0aa21a64af2802d0a470fb0f01cb33c04fafd2047111"
+  name = "honnef.co/go/tools"
+  packages = [
+    "arg",
+    "cmd/staticcheck",
+    "config",
+    "deprecated",
+    "facts",
+    "functions",
+    "go/types/typeutil",
+    "internal/cache",
+    "internal/passes/buildssa",
+    "internal/renameio",
+    "internal/sharedcheck",
+    "lint",
+    "lint/lintdsl",
+    "lint/lintutil",
+    "lint/lintutil/format",
+    "loader",
+    "printf",
+    "simple",
+    "ssa",
+    "ssautil",
+    "staticcheck",
+    "staticcheck/vrp",
+    "stylecheck",
+    "unused",
+    "version",
+  ]
+  pruneopts = "UT"
+  revision = "afd67930eec2a9ed3e9b19f684d17a062285f16a"
+  version = "2019.2.3"
 
 [solve-meta]
   analyzer-name = "dep"
@@ -229,10 +306,10 @@
     "github.com/stretchr/testify/assert",
     "github.com/stretchr/testify/require",
     "github.com/stretchr/testify/suite",
-    "github.com/uber-go/atomic",
     "github.com/uber/jaeger-lib/metrics",
     "github.com/uber/jaeger-lib/metrics/metricstest",
     "github.com/uber/jaeger-lib/metrics/prometheus",
+    "go.uber.org/atomic",
     "go.uber.org/zap",
     "go.uber.org/zap/zapcore",
   ]
diff --git a/vendor/github.com/uber/jaeger-client-go/Gopkg.toml b/vendor/github.com/uber/jaeger-client-go/Gopkg.toml
index 3e6ac35ae..1fed7f814 100644
--- a/vendor/github.com/uber/jaeger-client-go/Gopkg.toml
+++ b/vendor/github.com/uber/jaeger-client-go/Gopkg.toml
@@ -15,7 +15,7 @@
   version = "^1.1.3"
 
 [[constraint]]
-  name = "github.com/uber-go/atomic"
+  name = "go.uber.org/atomic"
   version = "^1"
 
 [[constraint]]
diff --git a/vendor/github.com/uber/jaeger-client-go/Makefile b/vendor/github.com/uber/jaeger-client-go/Makefile
index 74e11787a..0cfe6a5f6 100644
--- a/vendor/github.com/uber/jaeger-client-go/Makefile
+++ b/vendor/github.com/uber/jaeger-client-go/Makefile
@@ -1,5 +1,5 @@
 PROJECT_ROOT=github.com/uber/jaeger-client-go
-PACKAGES := $(shell go list ./... | awk -F/ 'NR>1 {print "./"$$4"/..."}' | grep -v -e ./thrift-gen/... -e ./thrift/... | sort -u)
+PACKAGES := . $(shell go list ./... | awk -F/ 'NR>1 {print "./"$$4"/..."}' | grep -v -e ./thrift-gen/... -e ./thrift/... | sort -u)
 # all .go files that don't exist in hidden directories
 ALL_SRC := $(shell find . -name "*.go" | grep -v -e vendor -e thrift-gen -e ./thrift/ \
         -e ".*/\..*" \
@@ -125,3 +125,4 @@ ifeq ($(CI_SKIP_LINT),true)
 else
 	make lint
 endif
+
diff --git a/vendor/github.com/uber/jaeger-client-go/README.md b/vendor/github.com/uber/jaeger-client-go/README.md
index 604d4b571..a3366114d 100644
--- a/vendor/github.com/uber/jaeger-client-go/README.md
+++ b/vendor/github.com/uber/jaeger-client-go/README.md
@@ -182,6 +182,29 @@ are available:
   1. `RateLimitingSampler` can be used to allow only a certain fixed
      number of traces to be sampled per second.
 
+#### Delayed sampling
+
+Version 2.20 introduced the ability to delay sampling decisions in the life cycle
+of the root span. It involves several features and architectural changes:
+  * **Shared sampling state**: the sampling state is shared across all local
+    (i.e. in-process) spans for a given trace.
+  * **New `SamplerV2` API** allows the sampler to be called at multiple points 
+    in the life cycle of a span:
+    * on span creation
+    * on overwriting span operation name
+    * on setting span tags
+    * on finishing the span
+  * **Final/non-final sampling state**: the new `SamplerV2` API allows the sampler
+    to indicate if the negative sampling decision is final or not (positive sampling
+    decisions are always final). If the decision is not final, the sampler will be
+    called again on further span life cycle events, like setting tags.
+
+These new features are used in the experimental `x.TagMatchingSampler`, which
+can sample a trace based on a certain tag added to the root
+span or one of its local (in-process) children. The sampler can be used with
+another experimental `x.PrioritySampler` that allows multiple samplers to try
+to make a sampling decision, in a certain priority order.
+
 ### Baggage Injection
 
 The OpenTracing spec allows for [baggage][baggage], which are key value pairs that are added
diff --git a/vendor/github.com/uber/jaeger-client-go/config/config.go b/vendor/github.com/uber/jaeger-client-go/config/config.go
index 6bce1b3b0..965f7c3ee 100644
--- a/vendor/github.com/uber/jaeger-client-go/config/config.go
+++ b/vendor/github.com/uber/jaeger-client-go/config/config.go
@@ -86,6 +86,9 @@ type SamplerConfig struct {
 	// jaeger-agent for the appropriate sampling strategy.
 	// Can be set by exporting an environment variable named JAEGER_SAMPLER_REFRESH_INTERVAL
 	SamplingRefreshInterval time.Duration `yaml:"samplingRefreshInterval"`
+
+	// Options can be used to programmatically pass additional options to the Remote sampler.
+	Options []jaeger.SamplerOption
 }
 
 // ReporterConfig configures the reporter. All fields are optional.
@@ -357,6 +360,7 @@ func (sc *SamplerConfig) NewSampler(
 		if sc.SamplingRefreshInterval != 0 {
 			options = append(options, jaeger.SamplerOptions.SamplingRefreshInterval(sc.SamplingRefreshInterval))
 		}
+		options = append(options, sc.Options...)
 		return jaeger.NewRemotelyControlledSampler(serviceName, options...), nil
 	}
 	return nil, fmt.Errorf("Unknown sampler type %v", sc.Type)
diff --git a/vendor/github.com/uber/jaeger-client-go/config/config_env.go b/vendor/github.com/uber/jaeger-client-go/config/config_env.go
index 14d69b11d..a729bd8fe 100644
--- a/vendor/github.com/uber/jaeger-client-go/config/config_env.go
+++ b/vendor/github.com/uber/jaeger-client-go/config/config_env.go
@@ -52,7 +52,11 @@ const (
 // FromEnv uses environment variables to set the tracer's Configuration
 func FromEnv() (*Configuration, error) {
 	c := &Configuration{}
+	return c.FromEnv()
+}
 
+// FromEnv uses environment variables and overrides existing tracer's Configuration
+func (c *Configuration) FromEnv() (*Configuration, error) {
 	if e := os.Getenv(envServiceName); e != "" {
 		c.ServiceName = e
 	}
@@ -77,13 +81,21 @@ func FromEnv() (*Configuration, error) {
 		c.Tags = parseTags(e)
 	}
 
-	if s, err := samplerConfigFromEnv(); err == nil {
+	if c.Sampler == nil {
+		c.Sampler = &SamplerConfig{}
+	}
+
+	if s, err := c.Sampler.samplerConfigFromEnv(); err == nil {
 		c.Sampler = s
 	} else {
 		return nil, errors.Wrap(err, "cannot obtain sampler config from env")
 	}
 
-	if r, err := reporterConfigFromEnv(); err == nil {
+	if c.Reporter == nil {
+		c.Reporter = &ReporterConfig{}
+	}
+
+	if r, err := c.Reporter.reporterConfigFromEnv(); err == nil {
 		c.Reporter = r
 	} else {
 		return nil, errors.Wrap(err, "cannot obtain reporter config from env")
@@ -93,9 +105,7 @@ func FromEnv() (*Configuration, error) {
 }
 
 // samplerConfigFromEnv creates a new SamplerConfig based on the environment variables
-func samplerConfigFromEnv() (*SamplerConfig, error) {
-	sc := &SamplerConfig{}
-
+func (sc *SamplerConfig) samplerConfigFromEnv() (*SamplerConfig, error) {
 	if e := os.Getenv(envSamplerType); e != "" {
 		sc.Type = e
 	}
@@ -135,9 +145,7 @@ func samplerConfigFromEnv() (*SamplerConfig, error) {
 }
 
 // reporterConfigFromEnv creates a new ReporterConfig based on the environment variables
-func reporterConfigFromEnv() (*ReporterConfig, error) {
-	rc := &ReporterConfig{}
-
+func (rc *ReporterConfig) reporterConfigFromEnv() (*ReporterConfig, error) {
 	if e := os.Getenv(envReporterMaxQueueSize); e != "" {
 		if value, err := strconv.ParseInt(e, 10, 0); err == nil {
 			rc.QueueSize = int(value)
diff --git a/vendor/github.com/uber/jaeger-client-go/constants.go b/vendor/github.com/uber/jaeger-client-go/constants.go
index e95b2ba09..0da47b02f 100644
--- a/vendor/github.com/uber/jaeger-client-go/constants.go
+++ b/vendor/github.com/uber/jaeger-client-go/constants.go
@@ -22,7 +22,7 @@ import (
 
 const (
 	// JaegerClientVersion is the version of the client library reported as Span tag.
-	JaegerClientVersion = "Go-2.19.0"
+	JaegerClientVersion = "Go-2.20.0"
 
 	// JaegerClientVersionTagKey is the name of the tag used to report client version.
 	JaegerClientVersionTagKey = "jaeger.version"
diff --git a/vendor/github.com/uber/jaeger-client-go/jaeger_thrift_span.go b/vendor/github.com/uber/jaeger-client-go/jaeger_thrift_span.go
index 6ce1caf87..f0f1afe2f 100644
--- a/vendor/github.com/uber/jaeger-client-go/jaeger_thrift_span.go
+++ b/vendor/github.com/uber/jaeger-client-go/jaeger_thrift_span.go
@@ -35,7 +35,7 @@ func BuildJaegerThrift(span *Span) *j.Span {
 		SpanId:        int64(span.context.spanID),
 		ParentSpanId:  int64(span.context.parentID),
 		OperationName: span.operationName,
-		Flags:         int32(span.context.flags),
+		Flags:         int32(span.context.samplingState.flags()),
 		StartTime:     startTime,
 		Duration:      duration,
 		Tags:          buildTags(span.tags, span.tracer.options.maxTagValueLength),
diff --git a/vendor/github.com/uber/jaeger-client-go/metrics.go b/vendor/github.com/uber/jaeger-client-go/metrics.go
index e56db9b73..50e4e22d6 100644
--- a/vendor/github.com/uber/jaeger-client-go/metrics.go
+++ b/vendor/github.com/uber/jaeger-client-go/metrics.go
@@ -26,6 +26,9 @@ type Metrics struct {
 	// Number of traces started by this tracer as not sampled
 	TracesStartedNotSampled metrics.Counter `metric:"traces" tags:"state=started,sampled=n" help:"Number of traces started by this tracer as not sampled"`
 
+	// Number of traces started by this tracer with delayed sampling
+	TracesStartedDelayedSampling metrics.Counter `metric:"traces" tags:"state=started,sampled=n" help:"Number of traces started by this tracer with delayed sampling"`
+
 	// Number of externally started sampled traces this tracer joined
 	TracesJoinedSampled metrics.Counter `metric:"traces" tags:"state=joined,sampled=y" help:"Number of externally started sampled traces this tracer joined"`
 
@@ -33,13 +36,22 @@ type Metrics struct {
 	TracesJoinedNotSampled metrics.Counter `metric:"traces" tags:"state=joined,sampled=n" help:"Number of externally started not-sampled traces this tracer joined"`
 
 	// Number of sampled spans started by this tracer
-	SpansStartedSampled metrics.Counter `metric:"started_spans" tags:"sampled=y" help:"Number of sampled spans started by this tracer"`
+	SpansStartedSampled metrics.Counter `metric:"started_spans" tags:"sampled=y" help:"Number of spans started by this tracer as sampled"`
+
+	// Number of not sampled spans started by this tracer
+	SpansStartedNotSampled metrics.Counter `metric:"started_spans" tags:"sampled=n" help:"Number of spans started by this tracer as not sampled"`
+
+	// Number of spans with delayed sampling started by this tracer
+	SpansStartedDelayedSampling metrics.Counter `metric:"started_spans" tags:"sampled=delayed" help:"Number of spans started by this tracer with delayed sampling"`
 
-	// Number of unsampled spans started by this tracer
-	SpansStartedNotSampled metrics.Counter `metric:"started_spans" tags:"sampled=n" help:"Number of unsampled spans started by this tracer"`
+	// Number of spans finished by this tracer
+	SpansFinishedSampled metrics.Counter `metric:"finished_spans" tags:"sampled=y" help:"Number of sampled spans finished by this tracer"`
+
+	// Number of spans finished by this tracer
+	SpansFinishedNotSampled metrics.Counter `metric:"finished_spans" tags:"sampled=n" help:"Number of not-sampled spans finished by this tracer"`
 
 	// Number of spans finished by this tracer
-	SpansFinished metrics.Counter `metric:"finished_spans" help:"Number of spans finished by this tracer"`
+	SpansFinishedDelayedSampling metrics.Counter `metric:"finished_spans" tags:"sampled=delayed" help:"Number of spans with delayed sampling finished by this tracer"`
 
 	// Number of errors decoding tracing context
 	DecodingErrors metrics.Counter `metric:"span_context_decoding_errors" help:"Number of errors decoding tracing context"`
diff --git a/vendor/github.com/uber/jaeger-client-go/propagation.go b/vendor/github.com/uber/jaeger-client-go/propagation.go
index 5b50cfb71..42fd64b58 100644
--- a/vendor/github.com/uber/jaeger-client-go/propagation.go
+++ b/vendor/github.com/uber/jaeger-client-go/propagation.go
@@ -193,7 +193,7 @@ func (p *BinaryPropagator) Inject(
 	if err := binary.Write(carrier, binary.BigEndian, sc.parentID); err != nil {
 		return err
 	}
-	if err := binary.Write(carrier, binary.BigEndian, sc.flags); err != nil {
+	if err := binary.Write(carrier, binary.BigEndian, sc.samplingState.flags()); err != nil {
 		return err
 	}
 
@@ -222,6 +222,7 @@ func (p *BinaryPropagator) Extract(abstractCarrier interface{}) (SpanContext, er
 		return emptyContext, opentracing.ErrInvalidCarrier
 	}
 	var ctx SpanContext
+	ctx.samplingState = &samplingState{}
 
 	if err := binary.Read(carrier, binary.BigEndian, &ctx.traceID); err != nil {
 		return emptyContext, opentracing.ErrSpanContextCorrupted
@@ -232,9 +233,12 @@ func (p *BinaryPropagator) Extract(abstractCarrier interface{}) (SpanContext, er
 	if err := binary.Read(carrier, binary.BigEndian, &ctx.parentID); err != nil {
 		return emptyContext, opentracing.ErrSpanContextCorrupted
 	}
-	if err := binary.Read(carrier, binary.BigEndian, &ctx.flags); err != nil {
+
+	var flags byte
+	if err := binary.Read(carrier, binary.BigEndian, &flags); err != nil {
 		return emptyContext, opentracing.ErrSpanContextCorrupted
 	}
+	ctx.samplingState.setFlags(flags)
 
 	// Handle the baggage items
 	var numBaggage int32
diff --git a/vendor/github.com/uber/jaeger-client-go/reporter.go b/vendor/github.com/uber/jaeger-client-go/reporter.go
index 27163ebe4..0b78cec20 100644
--- a/vendor/github.com/uber/jaeger-client-go/reporter.go
+++ b/vendor/github.com/uber/jaeger-client-go/reporter.go
@@ -28,6 +28,8 @@ import (
 // Reporter is called by the tracer when a span is completed to report the span to the tracing collector.
 type Reporter interface {
 	// Report submits a new span to collectors, possibly asynchronously and/or with buffering.
+	// If the reporter is processing Span asynchronously then it needs to Retain() the span,
+	// and then Release() it when no longer needed, to avoid span data corruption.
 	Report(span *Span)
 
 	// Close does a clean shutdown of the reporter, flushing any traces that may be buffered in memory.
diff --git a/vendor/github.com/uber/jaeger-client-go/sampler.go b/vendor/github.com/uber/jaeger-client-go/sampler.go
index ea6984e02..6195d59c5 100644
--- a/vendor/github.com/uber/jaeger-client-go/sampler.go
+++ b/vendor/github.com/uber/jaeger-client-go/sampler.go
@@ -17,19 +17,14 @@ package jaeger
 import (
 	"fmt"
 	"math"
-	"net/url"
 	"sync"
-	"sync/atomic"
-	"time"
 
-	"github.com/uber/jaeger-client-go/log"
 	"github.com/uber/jaeger-client-go/thrift-gen/sampling"
 	"github.com/uber/jaeger-client-go/utils"
 )
 
 const (
-	defaultSamplingRefreshInterval = time.Minute
-	defaultMaxOperations           = 2000
+	defaultMaxOperations = 2000
 )
 
 // Sampler decides whether a new trace should be sampled or not.
@@ -47,9 +42,7 @@ type Sampler interface {
 
 	// Equal checks if the `other` sampler is functionally equivalent
 	// to this sampler.
-	// TODO remove this function. This function is used to determine if 2 samplers are equivalent
-	// which does not bode well with the adaptive sampler which has to create all the composite samplers
-	// for the comparison to occur. This is expensive to do if only one sampler has changed.
+	// TODO (breaking change) remove this function. See PerOperationSampler.Equals for explanation.
 	Equal(other Sampler) bool
 }
 
@@ -57,17 +50,23 @@ type Sampler interface {
 
 // ConstSampler is a sampler that always makes the same decision.
 type ConstSampler struct {
+	legacySamplerV1Base
 	Decision bool
 	tags     []Tag
 }
 
 // NewConstSampler creates a ConstSampler.
-func NewConstSampler(sample bool) Sampler {
+func NewConstSampler(sample bool) *ConstSampler {
 	tags := []Tag{
 		{key: SamplerTypeTagKey, value: SamplerTypeConst},
 		{key: SamplerParamTagKey, value: sample},
 	}
-	return &ConstSampler{Decision: sample, tags: tags}
+	s := &ConstSampler{
+		Decision: sample,
+		tags:     tags,
+	}
+	s.delegate = s.IsSampled
+	return s
 }
 
 // IsSampled implements IsSampled() of Sampler.
@@ -88,11 +87,17 @@ func (s *ConstSampler) Equal(other Sampler) bool {
 	return false
 }
 
+// String is used to log sampler details.
+func (s *ConstSampler) String() string {
+	return fmt.Sprintf("ConstSampler(decision=%t)", s.Decision)
+}
+
 // -----------------------
 
 // ProbabilisticSampler is a sampler that randomly samples a certain percentage
 // of traces.
 type ProbabilisticSampler struct {
+	legacySamplerV1Base
 	samplingRate     float64
 	samplingBoundary uint64
 	tags             []Tag
@@ -114,16 +119,19 @@ func NewProbabilisticSampler(samplingRate float64) (*ProbabilisticSampler, error
 }
 
 func newProbabilisticSampler(samplingRate float64) *ProbabilisticSampler {
-	samplingRate = math.Max(0.0, math.Min(samplingRate, 1.0))
-	tags := []Tag{
+	s := new(ProbabilisticSampler)
+	s.delegate = s.IsSampled
+	return s.init(samplingRate)
+}
+
+func (s *ProbabilisticSampler) init(samplingRate float64) *ProbabilisticSampler {
+	s.samplingRate = math.Max(0.0, math.Min(samplingRate, 1.0))
+	s.samplingBoundary = uint64(float64(maxRandomNumber) * s.samplingRate)
+	s.tags = []Tag{
 		{key: SamplerTypeTagKey, value: SamplerTypeProbabilistic},
-		{key: SamplerParamTagKey, value: samplingRate},
-	}
-	return &ProbabilisticSampler{
-		samplingRate:     samplingRate,
-		samplingBoundary: uint64(float64(maxRandomNumber) * samplingRate),
-		tags:             tags,
+		{key: SamplerParamTagKey, value: s.samplingRate},
 	}
+	return s
 }
 
 // SamplingRate returns the sampling probability this sampled was constructed with.
@@ -149,65 +157,104 @@ func (s *ProbabilisticSampler) Equal(other Sampler) bool {
 	return false
 }
 
+// Update modifies in-place the sampling rate. Locking must be done externally.
+func (s *ProbabilisticSampler) Update(samplingRate float64) error {
+	if samplingRate < 0.0 || samplingRate > 1.0 {
+		return fmt.Errorf("Sampling Rate must be between 0.0 and 1.0, received %f", samplingRate)
+	}
+	s.init(samplingRate)
+	return nil
+}
+
+// String is used to log sampler details.
+func (s *ProbabilisticSampler) String() string {
+	return fmt.Sprintf("ProbabilisticSampler(samplingRate=%v)", s.samplingRate)
+}
+
 // -----------------------
 
-type rateLimitingSampler struct {
+// RateLimitingSampler samples at most maxTracesPerSecond. The distribution of sampled traces follows
+// burstiness of the service, i.e. a service with uniformly distributed requests will have those
+// requests sampled uniformly as well, but if requests are bursty, especially sub-second, then a
+// number of sequential requests can be sampled each second.
+type RateLimitingSampler struct {
+	legacySamplerV1Base
 	maxTracesPerSecond float64
-	rateLimiter        utils.RateLimiter
+	rateLimiter        *utils.ReconfigurableRateLimiter
 	tags               []Tag
 }
 
-// NewRateLimitingSampler creates a sampler that samples at most maxTracesPerSecond. The distribution of sampled
-// traces follows burstiness of the service, i.e. a service with uniformly distributed requests will have those
-// requests sampled uniformly as well, but if requests are bursty, especially sub-second, then a number of
-// sequential requests can be sampled each second.
-func NewRateLimitingSampler(maxTracesPerSecond float64) Sampler {
-	tags := []Tag{
+// NewRateLimitingSampler creates new RateLimitingSampler.
+func NewRateLimitingSampler(maxTracesPerSecond float64) *RateLimitingSampler {
+	s := new(RateLimitingSampler)
+	s.delegate = s.IsSampled
+	return s.init(maxTracesPerSecond)
+}
+
+func (s *RateLimitingSampler) init(maxTracesPerSecond float64) *RateLimitingSampler {
+	if s.rateLimiter == nil {
+		s.rateLimiter = utils.NewRateLimiter(maxTracesPerSecond, math.Max(maxTracesPerSecond, 1.0))
+	} else {
+		s.rateLimiter.Update(maxTracesPerSecond, math.Max(maxTracesPerSecond, 1.0))
+	}
+	s.maxTracesPerSecond = maxTracesPerSecond
+	s.tags = []Tag{
 		{key: SamplerTypeTagKey, value: SamplerTypeRateLimiting},
 		{key: SamplerParamTagKey, value: maxTracesPerSecond},
 	}
-	return &rateLimitingSampler{
-		maxTracesPerSecond: maxTracesPerSecond,
-		rateLimiter:        utils.NewRateLimiter(maxTracesPerSecond, math.Max(maxTracesPerSecond, 1.0)),
-		tags:               tags,
-	}
+	return s
 }
 
 // IsSampled implements IsSampled() of Sampler.
-func (s *rateLimitingSampler) IsSampled(id TraceID, operation string) (bool, []Tag) {
+func (s *RateLimitingSampler) IsSampled(id TraceID, operation string) (bool, []Tag) {
 	return s.rateLimiter.CheckCredit(1.0), s.tags
 }
 
-func (s *rateLimitingSampler) Close() {
+// Update reconfigures the rate limiter, while preserving its accumulated balance.
+// Locking must be done externally.
+func (s *RateLimitingSampler) Update(maxTracesPerSecond float64) {
+	if s.maxTracesPerSecond != maxTracesPerSecond {
+		s.init(maxTracesPerSecond)
+	}
+}
+
+// Close does nothing.
+func (s *RateLimitingSampler) Close() {
 	// nothing to do
 }
 
-func (s *rateLimitingSampler) Equal(other Sampler) bool {
-	if o, ok := other.(*rateLimitingSampler); ok {
+// Equal compares with another sampler.
+func (s *RateLimitingSampler) Equal(other Sampler) bool {
+	if o, ok := other.(*RateLimitingSampler); ok {
 		return s.maxTracesPerSecond == o.maxTracesPerSecond
 	}
 	return false
 }
 
+// String is used to log sampler details.
+func (s *RateLimitingSampler) String() string {
+	return fmt.Sprintf("RateLimitingSampler(maxTracesPerSecond=%v)", s.maxTracesPerSecond)
+}
+
 // -----------------------
 
-// GuaranteedThroughputProbabilisticSampler is a sampler that leverages both probabilisticSampler and
-// rateLimitingSampler. The rateLimitingSampler is used as a guaranteed lower bound sampler such that
+// GuaranteedThroughputProbabilisticSampler is a sampler that leverages both ProbabilisticSampler and
+// RateLimitingSampler. The RateLimitingSampler is used as a guaranteed lower bound sampler such that
 // every operation is sampled at least once in a time interval defined by the lowerBound. ie a lowerBound
 // of 1.0 / (60 * 10) will sample an operation at least once every 10 minutes.
 //
-// The probabilisticSampler is given higher priority when tags are emitted, ie. if IsSampled() for both
-// samplers return true, the tags for probabilisticSampler will be used.
+// The ProbabilisticSampler is given higher priority when tags are emitted, ie. if IsSampled() for both
+// samplers return true, the tags for ProbabilisticSampler will be used.
 type GuaranteedThroughputProbabilisticSampler struct {
 	probabilisticSampler *ProbabilisticSampler
-	lowerBoundSampler    Sampler
+	lowerBoundSampler    *RateLimitingSampler
 	tags                 []Tag
 	samplingRate         float64
 	lowerBound           float64
 }
 
 // NewGuaranteedThroughputProbabilisticSampler returns a delegating sampler that applies both
-// probabilisticSampler and rateLimitingSampler.
+// ProbabilisticSampler and RateLimitingSampler.
 func NewGuaranteedThroughputProbabilisticSampler(
 	lowerBound, samplingRate float64,
 ) (*GuaranteedThroughputProbabilisticSampler, error) {
@@ -224,8 +271,14 @@ func newGuaranteedThroughputProbabilisticSampler(lowerBound, samplingRate float6
 }
 
 func (s *GuaranteedThroughputProbabilisticSampler) setProbabilisticSampler(samplingRate float64) {
-	if s.probabilisticSampler == nil || s.samplingRate != samplingRate {
+	if s.probabilisticSampler == nil {
 		s.probabilisticSampler = newProbabilisticSampler(samplingRate)
+	} else if s.samplingRate != samplingRate {
+		s.probabilisticSampler.init(samplingRate)
+	}
+	// since we don't validate samplingRate, sampler may have clamped it to [0, 1] interval
+	samplingRate = s.probabilisticSampler.SamplingRate()
+	if s.samplingRate != samplingRate || s.tags == nil {
 		s.samplingRate = s.probabilisticSampler.SamplingRate()
 		s.tags = []Tag{
 			{key: SamplerTypeTagKey, value: SamplerTypeLowerBound},
@@ -252,7 +305,7 @@ func (s *GuaranteedThroughputProbabilisticSampler) Close() {
 
 // Equal implements Equal() of Sampler.
 func (s *GuaranteedThroughputProbabilisticSampler) Equal(other Sampler) bool {
-	// NB The Equal() function is expensive and will be removed. See adaptiveSampler.Equal() for
+	// NB The Equal() function is expensive and will be removed. See PerOperationSampler.Equal() for
 	// more information.
 	return false
 }
@@ -261,52 +314,116 @@ func (s *GuaranteedThroughputProbabilisticSampler) Equal(other Sampler) bool {
 func (s *GuaranteedThroughputProbabilisticSampler) update(lowerBound, samplingRate float64) {
 	s.setProbabilisticSampler(samplingRate)
 	if s.lowerBound != lowerBound {
-		s.lowerBoundSampler = NewRateLimitingSampler(lowerBound)
+		s.lowerBoundSampler.Update(lowerBound)
 		s.lowerBound = lowerBound
 	}
 }
 
 // -----------------------
 
-type adaptiveSampler struct {
+// PerOperationSampler is a delegating sampler that applies GuaranteedThroughputProbabilisticSampler
+// on a per-operation basis.
+type PerOperationSampler struct {
 	sync.RWMutex
 
 	samplers       map[string]*GuaranteedThroughputProbabilisticSampler
 	defaultSampler *ProbabilisticSampler
 	lowerBound     float64
 	maxOperations  int
+
+	// see description in PerOperationSamplerParams
+	operationNameLateBinding bool
 }
 
-// NewAdaptiveSampler returns a delegating sampler that applies both probabilisticSampler and
-// rateLimitingSampler via the guaranteedThroughputProbabilisticSampler. This sampler keeps track of all
-// operations and delegates calls to the respective guaranteedThroughputProbabilisticSampler.
-func NewAdaptiveSampler(strategies *sampling.PerOperationSamplingStrategies, maxOperations int) (Sampler, error) {
-	return newAdaptiveSampler(strategies, maxOperations), nil
+// NewAdaptiveSampler returns a new PerOperationSampler.
+// Deprecated: please use NewPerOperationSampler.
+func NewAdaptiveSampler(strategies *sampling.PerOperationSamplingStrategies, maxOperations int) (*PerOperationSampler, error) {
+	return NewPerOperationSampler(PerOperationSamplerParams{
+		MaxOperations: maxOperations,
+		Strategies:    strategies,
+	}), nil
 }
 
-func newAdaptiveSampler(strategies *sampling.PerOperationSamplingStrategies, maxOperations int) Sampler {
+// PerOperationSamplerParams defines parameters when creating PerOperationSampler.
+type PerOperationSamplerParams struct {
+	// Max number of operations that will be tracked. Other operations will be given default strategy.
+	MaxOperations int
+
+	// Opt-in feature for applications that require late binding of span name via explicit call to SetOperationName.
+	// When this feature is enabled, the sampler will return retryable=true from OnCreateSpan(), thus leaving
+	// the sampling decision as non-final (and the span as writeable). This may lead to degraded performance
+	// in applications that always provide the correct span name on trace creation.
+	//
+	// For backwards compatibility this option is off by default.
+	OperationNameLateBinding bool
+
+	// Initial configuration of the sampling strategies (usually retrieved from the backend by Remote Sampler).
+	Strategies *sampling.PerOperationSamplingStrategies
+}
+
+// NewPerOperationSampler returns a new PerOperationSampler.
+func NewPerOperationSampler(params PerOperationSamplerParams) *PerOperationSampler {
 	samplers := make(map[string]*GuaranteedThroughputProbabilisticSampler)
-	for _, strategy := range strategies.PerOperationStrategies {
+	for _, strategy := range params.Strategies.PerOperationStrategies {
 		sampler := newGuaranteedThroughputProbabilisticSampler(
-			strategies.DefaultLowerBoundTracesPerSecond,
+			params.Strategies.DefaultLowerBoundTracesPerSecond,
 			strategy.ProbabilisticSampling.SamplingRate,
 		)
 		samplers[strategy.Operation] = sampler
 	}
-	return &adaptiveSampler{
-		samplers:       samplers,
-		defaultSampler: newProbabilisticSampler(strategies.DefaultSamplingProbability),
-		lowerBound:     strategies.DefaultLowerBoundTracesPerSecond,
-		maxOperations:  maxOperations,
+	return &PerOperationSampler{
+		samplers:                 samplers,
+		defaultSampler:           newProbabilisticSampler(params.Strategies.DefaultSamplingProbability),
+		lowerBound:               params.Strategies.DefaultLowerBoundTracesPerSecond,
+		maxOperations:            params.MaxOperations,
+		operationNameLateBinding: params.OperationNameLateBinding,
 	}
 }
 
-func (s *adaptiveSampler) IsSampled(id TraceID, operation string) (bool, []Tag) {
+// IsSampled is not used and only exists to match Sampler V1 API.
+// TODO (breaking change) remove when upgrading everything to SamplerV2
+func (s *PerOperationSampler) IsSampled(id TraceID, operation string) (bool, []Tag) {
+	return false, nil
+}
+
+func (s *PerOperationSampler) trySampling(span *Span, operationName string) (bool, []Tag) {
+	samplerV1 := s.getSamplerForOperation(operationName)
+	var sampled bool
+	var tags []Tag
+	if span.context.samplingState.isLocalRootSpan(span.context.spanID) {
+		sampled, tags = samplerV1.IsSampled(span.context.TraceID(), operationName)
+	}
+	return sampled, tags
+}
+
+// OnCreateSpan implements OnCreateSpan of SamplerV2.
+func (s *PerOperationSampler) OnCreateSpan(span *Span) SamplingDecision {
+	sampled, tags := s.trySampling(span, span.OperationName())
+	return SamplingDecision{Sample: sampled, Retryable: s.operationNameLateBinding, Tags: tags}
+}
+
+// OnSetOperationName implements OnSetOperationName of SamplerV2.
+func (s *PerOperationSampler) OnSetOperationName(span *Span, operationName string) SamplingDecision {
+	sampled, tags := s.trySampling(span, operationName)
+	return SamplingDecision{Sample: sampled, Retryable: false, Tags: tags}
+}
+
+// OnSetTag implements OnSetTag of SamplerV2.
+func (s *PerOperationSampler) OnSetTag(span *Span, key string, value interface{}) SamplingDecision {
+	return SamplingDecision{Sample: false, Retryable: true}
+}
+
+// OnFinishSpan implements OnFinishSpan of SamplerV2.
+func (s *PerOperationSampler) OnFinishSpan(span *Span) SamplingDecision {
+	return SamplingDecision{Sample: false, Retryable: true}
+}
+
+func (s *PerOperationSampler) getSamplerForOperation(operation string) Sampler {
 	s.RLock()
 	sampler, ok := s.samplers[operation]
 	if ok {
 		defer s.RUnlock()
-		return sampler.IsSampled(id, operation)
+		return sampler
 	}
 	s.RUnlock()
 	s.Lock()
@@ -315,18 +432,19 @@ func (s *adaptiveSampler) IsSampled(id TraceID, operation string) (bool, []Tag)
 	// Check if sampler has already been created
 	sampler, ok = s.samplers[operation]
 	if ok {
-		return sampler.IsSampled(id, operation)
+		return sampler
 	}
 	// Store only up to maxOperations of unique ops.
 	if len(s.samplers) >= s.maxOperations {
-		return s.defaultSampler.IsSampled(id, operation)
+		return s.defaultSampler
 	}
 	newSampler := newGuaranteedThroughputProbabilisticSampler(s.lowerBound, s.defaultSampler.SamplingRate())
 	s.samplers[operation] = newSampler
-	return newSampler.IsSampled(id, operation)
+	return newSampler
 }
 
-func (s *adaptiveSampler) Close() {
+// Close invokes Close on all underlying samplers.
+func (s *PerOperationSampler) Close() {
 	s.Lock()
 	defer s.Unlock()
 	for _, sampler := range s.samplers {
@@ -335,16 +453,18 @@ func (s *adaptiveSampler) Close() {
 	s.defaultSampler.Close()
 }
 
-func (s *adaptiveSampler) Equal(other Sampler) bool {
-	// NB The Equal() function is overly expensive for adaptiveSampler since it's composed of multiple
+// Equal is not used.
+// TODO (breaking change) remove this in the future
+func (s *PerOperationSampler) Equal(other Sampler) bool {
+	// NB The Equal() function is overly expensive for PerOperationSampler since it's composed of multiple
 	// samplers which all need to be initialized before this function can be called for a comparison.
-	// Therefore, adaptiveSampler uses the update() function to only alter the samplers that need
+	// Therefore, PerOperationSampler uses the update() function to only alter the samplers that need
 	// changing. Hence this function always returns false so that the update function can be called.
 	// Once the Equal() function is removed from the Sampler API, this will no longer be needed.
 	return false
 }
 
-func (s *adaptiveSampler) update(strategies *sampling.PerOperationSamplingStrategies) {
+func (s *PerOperationSampler) update(strategies *sampling.PerOperationSamplingStrategies) {
 	s.Lock()
 	defer s.Unlock()
 	newSamplers := map[string]*GuaranteedThroughputProbabilisticSampler{}
@@ -369,191 +489,3 @@ func (s *adaptiveSampler) update(strategies *sampling.PerOperationSamplingStrate
 	}
 	s.samplers = newSamplers
 }
-
-// -----------------------
-
-// RemotelyControlledSampler is a delegating sampler that polls a remote server
-// for the appropriate sampling strategy, constructs a corresponding sampler and
-// delegates to it for sampling decisions.
-type RemotelyControlledSampler struct {
-	// These fields must be first in the struct because `sync/atomic` expects 64-bit alignment.
-	// Cf. https://github.com/uber/jaeger-client-go/issues/155, https://goo.gl/zW7dgq
-	closed int64 // 0 - not closed, 1 - closed
-
-	sync.RWMutex
-	samplerOptions
-
-	serviceName string
-	manager     sampling.SamplingManager
-	doneChan    chan *sync.WaitGroup
-}
-
-type httpSamplingManager struct {
-	serverURL string
-}
-
-func (s *httpSamplingManager) GetSamplingStrategy(serviceName string) (*sampling.SamplingStrategyResponse, error) {
-	var out sampling.SamplingStrategyResponse
-	v := url.Values{}
-	v.Set("service", serviceName)
-	if err := utils.GetJSON(s.serverURL+"?"+v.Encode(), &out); err != nil {
-		return nil, err
-	}
-	return &out, nil
-}
-
-// NewRemotelyControlledSampler creates a sampler that periodically pulls
-// the sampling strategy from an HTTP sampling server (e.g. jaeger-agent).
-func NewRemotelyControlledSampler(
-	serviceName string,
-	opts ...SamplerOption,
-) *RemotelyControlledSampler {
-	options := applySamplerOptions(opts...)
-	sampler := &RemotelyControlledSampler{
-		samplerOptions: options,
-		serviceName:    serviceName,
-		manager:        &httpSamplingManager{serverURL: options.samplingServerURL},
-		doneChan:       make(chan *sync.WaitGroup),
-	}
-	go sampler.pollController()
-	return sampler
-}
-
-func applySamplerOptions(opts ...SamplerOption) samplerOptions {
-	options := samplerOptions{}
-	for _, option := range opts {
-		option(&options)
-	}
-	if options.sampler == nil {
-		options.sampler = newProbabilisticSampler(0.001)
-	}
-	if options.logger == nil {
-		options.logger = log.NullLogger
-	}
-	if options.maxOperations <= 0 {
-		options.maxOperations = defaultMaxOperations
-	}
-	if options.samplingServerURL == "" {
-		options.samplingServerURL = DefaultSamplingServerURL
-	}
-	if options.metrics == nil {
-		options.metrics = NewNullMetrics()
-	}
-	if options.samplingRefreshInterval <= 0 {
-		options.samplingRefreshInterval = defaultSamplingRefreshInterval
-	}
-	return options
-}
-
-// IsSampled implements IsSampled() of Sampler.
-func (s *RemotelyControlledSampler) IsSampled(id TraceID, operation string) (bool, []Tag) {
-	s.RLock()
-	defer s.RUnlock()
-	return s.sampler.IsSampled(id, operation)
-}
-
-// Close implements Close() of Sampler.
-func (s *RemotelyControlledSampler) Close() {
-	if swapped := atomic.CompareAndSwapInt64(&s.closed, 0, 1); !swapped {
-		s.logger.Error("Repeated attempt to close the sampler is ignored")
-		return
-	}
-
-	var wg sync.WaitGroup
-	wg.Add(1)
-	s.doneChan <- &wg
-	wg.Wait()
-}
-
-// Equal implements Equal() of Sampler.
-func (s *RemotelyControlledSampler) Equal(other Sampler) bool {
-	// NB The Equal() function is expensive and will be removed. See adaptiveSampler.Equal() for
-	// more information.
-	if o, ok := other.(*RemotelyControlledSampler); ok {
-		s.RLock()
-		o.RLock()
-		defer s.RUnlock()
-		defer o.RUnlock()
-		return s.sampler.Equal(o.sampler)
-	}
-	return false
-}
-
-func (s *RemotelyControlledSampler) pollController() {
-	ticker := time.NewTicker(s.samplingRefreshInterval)
-	defer ticker.Stop()
-	s.pollControllerWithTicker(ticker)
-}
-
-func (s *RemotelyControlledSampler) pollControllerWithTicker(ticker *time.Ticker) {
-	for {
-		select {
-		case <-ticker.C:
-			s.updateSampler()
-		case wg := <-s.doneChan:
-			wg.Done()
-			return
-		}
-	}
-}
-
-func (s *RemotelyControlledSampler) getSampler() Sampler {
-	s.Lock()
-	defer s.Unlock()
-	return s.sampler
-}
-
-func (s *RemotelyControlledSampler) setSampler(sampler Sampler) {
-	s.Lock()
-	defer s.Unlock()
-	s.sampler = sampler
-}
-
-func (s *RemotelyControlledSampler) updateSampler() {
-	res, err := s.manager.GetSamplingStrategy(s.serviceName)
-	if err != nil {
-		s.metrics.SamplerQueryFailure.Inc(1)
-		s.logger.Infof("Unable to query sampling strategy: %v", err)
-		return
-	}
-	s.Lock()
-	defer s.Unlock()
-
-	s.metrics.SamplerRetrieved.Inc(1)
-	if strategies := res.GetOperationSampling(); strategies != nil {
-		s.updateAdaptiveSampler(strategies)
-	} else {
-		err = s.updateRateLimitingOrProbabilisticSampler(res)
-	}
-	if err != nil {
-		s.metrics.SamplerUpdateFailure.Inc(1)
-		s.logger.Infof("Unable to handle sampling strategy response %+v. Got error: %v", res, err)
-		return
-	}
-	s.metrics.SamplerUpdated.Inc(1)
-}
-
-// NB: this function should only be called while holding a Write lock
-func (s *RemotelyControlledSampler) updateAdaptiveSampler(strategies *sampling.PerOperationSamplingStrategies) {
-	if adaptiveSampler, ok := s.sampler.(*adaptiveSampler); ok {
-		adaptiveSampler.update(strategies)
-	} else {
-		s.sampler = newAdaptiveSampler(strategies, s.maxOperations)
-	}
-}
-
-// NB: this function should only be called while holding a Write lock
-func (s *RemotelyControlledSampler) updateRateLimitingOrProbabilisticSampler(res *sampling.SamplingStrategyResponse) error {
-	var newSampler Sampler
-	if probabilistic := res.GetProbabilisticSampling(); probabilistic != nil {
-		newSampler = newProbabilisticSampler(probabilistic.SamplingRate)
-	} else if rateLimiting := res.GetRateLimitingSampling(); rateLimiting != nil {
-		newSampler = NewRateLimitingSampler(float64(rateLimiting.MaxTracesPerSecond))
-	} else {
-		return fmt.Errorf("Unsupported sampling strategy type %v", res.GetStrategyType())
-	}
-	if !s.sampler.Equal(newSampler) {
-		s.sampler = newSampler
-	}
-	return nil
-}
diff --git a/vendor/github.com/uber/jaeger-client-go/sampler_remote.go b/vendor/github.com/uber/jaeger-client-go/sampler_remote.go
new file mode 100644
index 000000000..9bd0c9822
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/sampler_remote.go
@@ -0,0 +1,334 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// 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.
+
+package jaeger
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/uber/jaeger-client-go/thrift-gen/sampling"
+)
+
+const (
+	defaultSamplingRefreshInterval = time.Minute
+)
+
+// SamplingStrategyFetcher is used to fetch sampling strategy updates from remote server.
+type SamplingStrategyFetcher interface {
+	Fetch(service string) ([]byte, error)
+}
+
+// SamplingStrategyParser is used to parse sampling strategy updates. The output object
+// should be of the type that is recognized by the SamplerUpdaters.
+type SamplingStrategyParser interface {
+	Parse(response []byte) (interface{}, error)
+}
+
+// SamplerUpdater is used by RemotelyControlledSampler to apply sampling strategies,
+// retrieved from remote config server, to the current sampler. The updater can modify
+// the sampler in-place if sampler supports it, or create a new one.
+//
+// If the strategy does not contain configuration for the sampler in question,
+// updater must return modifiedSampler=nil to give other updaters a chance to inspect
+// the sampling strategy response.
+//
+// RemotelyControlledSampler invokes the updaters while holding a lock on the main sampler.
+type SamplerUpdater interface {
+	Update(sampler SamplerV2, strategy interface{}) (modified SamplerV2, err error)
+}
+
+// RemotelyControlledSampler is a delegating sampler that polls a remote server
+// for the appropriate sampling strategy, constructs a corresponding sampler and
+// delegates to it for sampling decisions.
+type RemotelyControlledSampler struct {
+	// These fields must be first in the struct because `sync/atomic` expects 64-bit alignment.
+	// Cf. https://github.com/uber/jaeger-client-go/issues/155, https://goo.gl/zW7dgq
+	closed int64 // 0 - not closed, 1 - closed
+
+	sync.RWMutex
+	samplerOptions
+
+	serviceName string
+	doneChan    chan *sync.WaitGroup
+}
+
+// NewRemotelyControlledSampler creates a sampler that periodically pulls
+// the sampling strategy from an HTTP sampling server (e.g. jaeger-agent).
+func NewRemotelyControlledSampler(
+	serviceName string,
+	opts ...SamplerOption,
+) *RemotelyControlledSampler {
+	options := new(samplerOptions).applyOptionsAndDefaults(opts...)
+	sampler := &RemotelyControlledSampler{
+		samplerOptions: *options,
+		serviceName:    serviceName,
+		doneChan:       make(chan *sync.WaitGroup),
+	}
+	go sampler.pollController()
+	return sampler
+}
+
+// IsSampled implements IsSampled() of Sampler.
+// TODO (breaking change) remove when Sampler V1 is removed
+func (s *RemotelyControlledSampler) IsSampled(id TraceID, operation string) (bool, []Tag) {
+	return false, nil
+}
+
+// OnCreateSpan implements OnCreateSpan of SamplerV2.
+func (s *RemotelyControlledSampler) OnCreateSpan(span *Span) SamplingDecision {
+	return s.sampler.OnCreateSpan(span)
+}
+
+// OnSetOperationName implements OnSetOperationName of SamplerV2.
+func (s *RemotelyControlledSampler) OnSetOperationName(span *Span, operationName string) SamplingDecision {
+	return s.sampler.OnSetOperationName(span, operationName)
+}
+
+// OnSetTag implements OnSetTag of SamplerV2.
+func (s *RemotelyControlledSampler) OnSetTag(span *Span, key string, value interface{}) SamplingDecision {
+	return s.sampler.OnSetTag(span, key, value)
+}
+
+// OnFinishSpan implements OnFinishSpan of SamplerV2.
+func (s *RemotelyControlledSampler) OnFinishSpan(span *Span) SamplingDecision {
+	return s.sampler.OnFinishSpan(span)
+}
+
+// Close implements Close() of Sampler.
+func (s *RemotelyControlledSampler) Close() {
+	if swapped := atomic.CompareAndSwapInt64(&s.closed, 0, 1); !swapped {
+		s.logger.Error("Repeated attempt to close the sampler is ignored")
+		return
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	s.doneChan <- &wg
+	wg.Wait()
+}
+
+// Equal implements Equal() of Sampler.
+func (s *RemotelyControlledSampler) Equal(other Sampler) bool {
+	// NB The Equal() function is expensive and will be removed. See PerOperationSampler.Equal() for
+	// more information.
+	return false
+}
+
+func (s *RemotelyControlledSampler) pollController() {
+	ticker := time.NewTicker(s.samplingRefreshInterval)
+	defer ticker.Stop()
+	s.pollControllerWithTicker(ticker)
+}
+
+func (s *RemotelyControlledSampler) pollControllerWithTicker(ticker *time.Ticker) {
+	for {
+		select {
+		case <-ticker.C:
+			s.UpdateSampler()
+		case wg := <-s.doneChan:
+			wg.Done()
+			return
+		}
+	}
+}
+
+// Sampler returns the currently active sampler.
+func (s *RemotelyControlledSampler) Sampler() SamplerV2 {
+	s.Lock()
+	defer s.Unlock()
+	return s.sampler
+}
+
+func (s *RemotelyControlledSampler) setSampler(sampler SamplerV2) {
+	s.Lock()
+	defer s.Unlock()
+	s.sampler = sampler
+}
+
+// UpdateSampler forces the sampler to fetch sampling strategy from backend server.
+// This function is called automatically on a timer, but can also be safely called manually, e.g. from tests.
+func (s *RemotelyControlledSampler) UpdateSampler() {
+	res, err := s.samplingFetcher.Fetch(s.serviceName)
+	if err != nil {
+		s.metrics.SamplerQueryFailure.Inc(1)
+		s.logger.Infof("failed to fetch sampling strategy: %v", err)
+		return
+	}
+	strategy, err := s.samplingParser.Parse(res)
+	if err != nil {
+		s.metrics.SamplerUpdateFailure.Inc(1)
+		s.logger.Infof("failed to parse sampling strategy response: %v", err)
+		return
+	}
+
+	s.Lock()
+	defer s.Unlock()
+
+	s.metrics.SamplerRetrieved.Inc(1)
+	if err := s.updateSamplerViaUpdaters(strategy); err != nil {
+		s.metrics.SamplerUpdateFailure.Inc(1)
+		s.logger.Infof("failed to handle sampling strategy response %+v. Got error: %v", res, err)
+		return
+	}
+	s.metrics.SamplerUpdated.Inc(1)
+}
+
+// NB: this function should only be called while holding a Write lock
+func (s *RemotelyControlledSampler) updateSamplerViaUpdaters(strategy interface{}) error {
+	for _, updater := range s.updaters {
+		sampler, err := updater.Update(s.sampler, strategy)
+		if err != nil {
+			return err
+		}
+		if sampler != nil {
+			s.sampler = sampler
+			return nil
+		}
+	}
+	return fmt.Errorf("unsupported sampling strategy %+v", strategy)
+}
+
+// -----------------------
+
+// ProbabilisticSamplerUpdater is used by RemotelyControlledSampler to parse sampling configuration.
+type ProbabilisticSamplerUpdater struct{}
+
+// Update implements Update of SamplerUpdater.
+func (u *ProbabilisticSamplerUpdater) Update(sampler SamplerV2, strategy interface{}) (SamplerV2, error) {
+	type response interface {
+		GetProbabilisticSampling() *sampling.ProbabilisticSamplingStrategy
+	}
+	var _ response = new(sampling.SamplingStrategyResponse) // sanity signature check
+	if resp, ok := strategy.(response); ok {
+		if probabilistic := resp.GetProbabilisticSampling(); probabilistic != nil {
+			if ps, ok := sampler.(*ProbabilisticSampler); ok {
+				if err := ps.Update(probabilistic.SamplingRate); err != nil {
+					return nil, err
+				}
+				return sampler, nil
+			}
+			return newProbabilisticSampler(probabilistic.SamplingRate), nil
+		}
+	}
+	return nil, nil
+}
+
+// -----------------------
+
+// RateLimitingSamplerUpdater is used by RemotelyControlledSampler to parse sampling configuration.
+type RateLimitingSamplerUpdater struct{}
+
+// Update implements Update of SamplerUpdater.
+func (u *RateLimitingSamplerUpdater) Update(sampler SamplerV2, strategy interface{}) (SamplerV2, error) {
+	type response interface {
+		GetRateLimitingSampling() *sampling.RateLimitingSamplingStrategy
+	}
+	var _ response = new(sampling.SamplingStrategyResponse) // sanity signature check
+	if resp, ok := strategy.(response); ok {
+		if rateLimiting := resp.GetRateLimitingSampling(); rateLimiting != nil {
+			rateLimit := float64(rateLimiting.MaxTracesPerSecond)
+			if rl, ok := sampler.(*RateLimitingSampler); ok {
+				rl.Update(rateLimit)
+				return rl, nil
+			}
+			return NewRateLimitingSampler(rateLimit), nil
+		}
+	}
+	return nil, nil
+}
+
+// -----------------------
+
+// AdaptiveSamplerUpdater is used by RemotelyControlledSampler to parse sampling configuration.
+type AdaptiveSamplerUpdater struct {
+	MaxOperations            int // required
+	OperationNameLateBinding bool
+}
+
+// Update implements Update of SamplerUpdater.
+func (u *AdaptiveSamplerUpdater) Update(sampler SamplerV2, strategy interface{}) (SamplerV2, error) {
+	type response interface {
+		GetOperationSampling() *sampling.PerOperationSamplingStrategies
+	}
+	var _ response = new(sampling.SamplingStrategyResponse) // sanity signature check
+	if p, ok := strategy.(response); ok {
+		if operations := p.GetOperationSampling(); operations != nil {
+			if as, ok := sampler.(*PerOperationSampler); ok {
+				as.update(operations)
+				return as, nil
+			}
+			return NewPerOperationSampler(PerOperationSamplerParams{
+				MaxOperations:            u.MaxOperations,
+				OperationNameLateBinding: u.OperationNameLateBinding,
+				Strategies:               operations,
+			}), nil
+		}
+	}
+	return nil, nil
+}
+
+// -----------------------
+
+type httpSamplingStrategyFetcher struct {
+	serverURL string
+	logger    Logger
+}
+
+func (f *httpSamplingStrategyFetcher) Fetch(serviceName string) ([]byte, error) {
+	v := url.Values{}
+	v.Set("service", serviceName)
+	uri := f.serverURL + "?" + v.Encode()
+
+	// TODO create and reuse http.Client with proper timeout settings, etc.
+	resp, err := http.Get(uri)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		if err := resp.Body.Close(); err != nil {
+			f.logger.Error(fmt.Sprintf("failed to close HTTP response body: %+v", err))
+		}
+	}()
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	if resp.StatusCode >= 400 {
+		return nil, fmt.Errorf("StatusCode: %d, Body: %s", resp.StatusCode, body)
+	}
+
+	return body, nil
+}
+
+// -----------------------
+
+type samplingStrategyParser struct{}
+
+func (p *samplingStrategyParser) Parse(response []byte) (interface{}, error) {
+	strategy := new(sampling.SamplingStrategyResponse)
+	if err := json.Unmarshal(response, strategy); err != nil {
+		return nil, err
+	}
+	return strategy, nil
+}
diff --git a/vendor/github.com/uber/jaeger-client-go/sampler_options.go b/vendor/github.com/uber/jaeger-client-go/sampler_remote_options.go
index 75d28a561..7a292effc 100644
--- a/vendor/github.com/uber/jaeger-client-go/sampler_options.go
+++ b/vendor/github.com/uber/jaeger-client-go/sampler_remote_options.go
@@ -16,6 +16,8 @@ package jaeger
 
 import (
 	"time"
+
+	"github.com/uber/jaeger-client-go/log"
 )
 
 // SamplerOption is a function that sets some option on the sampler
@@ -27,10 +29,13 @@ var SamplerOptions samplerOptions
 type samplerOptions struct {
 	metrics                 *Metrics
 	maxOperations           int
-	sampler                 Sampler
+	sampler                 SamplerV2
 	logger                  Logger
 	samplingServerURL       string
 	samplingRefreshInterval time.Duration
+	samplingFetcher         SamplingStrategyFetcher
+	samplingParser          SamplingStrategyParser
+	updaters                []SamplerUpdater
 }
 
 // Metrics creates a SamplerOption that initializes Metrics on the sampler,
@@ -53,7 +58,7 @@ func (samplerOptions) MaxOperations(maxOperations int) SamplerOption {
 // to use before a remote sampler is created and used.
 func (samplerOptions) InitialSampler(sampler Sampler) SamplerOption {
 	return func(o *samplerOptions) {
-		o.sampler = sampler
+		o.sampler = samplerV1toV2(sampler)
 	}
 }
 
@@ -79,3 +84,65 @@ func (samplerOptions) SamplingRefreshInterval(samplingRefreshInterval time.Durat
 		o.samplingRefreshInterval = samplingRefreshInterval
 	}
 }
+
+// SamplingStrategyFetcher creates a SamplerOption that initializes sampling strategy fetcher.
+func (samplerOptions) SamplingStrategyFetcher(fetcher SamplingStrategyFetcher) SamplerOption {
+	return func(o *samplerOptions) {
+		o.samplingFetcher = fetcher
+	}
+}
+
+// SamplingStrategyParser creates a SamplerOption that initializes sampling strategy parser.
+func (samplerOptions) SamplingStrategyParser(parser SamplingStrategyParser) SamplerOption {
+	return func(o *samplerOptions) {
+		o.samplingParser = parser
+	}
+}
+
+// Updaters creates a SamplerOption that initializes sampler updaters.
+func (samplerOptions) Updaters(updaters ...SamplerUpdater) SamplerOption {
+	return func(o *samplerOptions) {
+		o.updaters = updaters
+	}
+}
+
+func (o *samplerOptions) applyOptionsAndDefaults(opts ...SamplerOption) *samplerOptions {
+	for _, option := range opts {
+		option(o)
+	}
+	if o.sampler == nil {
+		o.sampler = newProbabilisticSampler(0.001)
+	}
+	if o.logger == nil {
+		o.logger = log.NullLogger
+	}
+	if o.maxOperations <= 0 {
+		o.maxOperations = defaultMaxOperations
+	}
+	if o.samplingServerURL == "" {
+		o.samplingServerURL = DefaultSamplingServerURL
+	}
+	if o.metrics == nil {
+		o.metrics = NewNullMetrics()
+	}
+	if o.samplingRefreshInterval <= 0 {
+		o.samplingRefreshInterval = defaultSamplingRefreshInterval
+	}
+	if o.samplingFetcher == nil {
+		o.samplingFetcher = &httpSamplingStrategyFetcher{
+			serverURL: o.samplingServerURL,
+			logger:    o.logger,
+		}
+	}
+	if o.samplingParser == nil {
+		o.samplingParser = new(samplingStrategyParser)
+	}
+	if o.updaters == nil {
+		o.updaters = []SamplerUpdater{
+			&AdaptiveSamplerUpdater{MaxOperations: o.maxOperations},
+			new(ProbabilisticSamplerUpdater),
+			new(RateLimitingSamplerUpdater),
+		}
+	}
+	return o
+}
diff --git a/vendor/github.com/uber/jaeger-client-go/sampler_v2.go b/vendor/github.com/uber/jaeger-client-go/sampler_v2.go
new file mode 100644
index 000000000..a50671a23
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/sampler_v2.go
@@ -0,0 +1,93 @@
+// Copyright (c) 2019 Uber Technologies, Inc.
+//
+// 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.
+
+package jaeger
+
+// SamplingDecision is returned by the V2 samplers.
+type SamplingDecision struct {
+	Sample    bool
+	Retryable bool
+	Tags      []Tag
+}
+
+// SamplerV2 is an extension of the V1 samplers that allows sampling decisions
+// be made at different points of the span lifecycle.
+type SamplerV2 interface {
+	OnCreateSpan(span *Span) SamplingDecision
+	OnSetOperationName(span *Span, operationName string) SamplingDecision
+	OnSetTag(span *Span, key string, value interface{}) SamplingDecision
+	OnFinishSpan(span *Span) SamplingDecision
+
+	// Close does a clean shutdown of the sampler, stopping any background
+	// go-routines it may have started.
+	Close()
+}
+
+// samplerV1toV2 wraps legacy V1 sampler into an adapter that make it look like V2.
+func samplerV1toV2(s Sampler) SamplerV2 {
+	if s2, ok := s.(SamplerV2); ok {
+		return s2
+	}
+	type legacySamplerV1toV2Adapter struct {
+		legacySamplerV1Base
+	}
+	return &legacySamplerV1toV2Adapter{
+		legacySamplerV1Base: legacySamplerV1Base{
+			delegate: s.IsSampled,
+		},
+	}
+}
+
+// SamplerV2Base can be used by V2 samplers to implement dummy V1 methods.
+// Supporting V1 API is required because Tracer configuration only accepts V1 Sampler
+// for backwards compatibility reasons.
+// TODO (breaking change) remove this in the next major release
+type SamplerV2Base struct{}
+
+// IsSampled implements IsSampled of Sampler.
+func (SamplerV2Base) IsSampled(id TraceID, operation string) (sampled bool, tags []Tag) {
+	return false, nil
+}
+
+// Close implements Close of Sampler.
+func (SamplerV2Base) Close() {}
+
+// Equal implements Equal of Sampler.
+func (SamplerV2Base) Equal(other Sampler) bool { return false }
+
+// legacySamplerV1Base is used as a base for simple samplers that only implement
+// the legacy isSampled() function that is not sensitive to its arguments.
+type legacySamplerV1Base struct {
+	delegate func(id TraceID, operation string) (sampled bool, tags []Tag)
+}
+
+func (s *legacySamplerV1Base) OnCreateSpan(span *Span) SamplingDecision {
+	isSampled, tags := s.delegate(span.context.traceID, span.operationName)
+	return SamplingDecision{Sample: isSampled, Retryable: false, Tags: tags}
+}
+
+func (s *legacySamplerV1Base) OnSetOperationName(span *Span, operationName string) SamplingDecision {
+	isSampled, tags := s.delegate(span.context.traceID, span.operationName)
+	return SamplingDecision{Sample: isSampled, Retryable: false, Tags: tags}
+}
+
+func (s *legacySamplerV1Base) OnSetTag(span *Span, key string, value interface{}) SamplingDecision {
+	return SamplingDecision{Sample: false, Retryable: true}
+}
+
+func (s *legacySamplerV1Base) OnFinishSpan(span *Span) SamplingDecision {
+	return SamplingDecision{Sample: false, Retryable: true}
+}
+
+func (s *legacySamplerV1Base) Close() {}
diff --git a/vendor/github.com/uber/jaeger-client-go/span.go b/vendor/github.com/uber/jaeger-client-go/span.go
index 9df8b6017..bbf6fb068 100644
--- a/vendor/github.com/uber/jaeger-client-go/span.go
+++ b/vendor/github.com/uber/jaeger-client-go/span.go
@@ -34,6 +34,7 @@ type Span struct {
 
 	tracer *Tracer
 
+	// TODO: (breaking change) change to use a pointer
 	context SpanContext
 
 	// The name of the "operation" this span is an instance of.
@@ -65,18 +66,26 @@ type Span struct {
 }
 
 // Tag is a simple key value wrapper.
-// TODO deprecate in the next major release, use opentracing.Tag instead.
+// TODO (breaking change) deprecate in the next major release, use opentracing.Tag instead.
 type Tag struct {
 	key   string
 	value interface{}
 }
 
+// NewTag creates a new Tag.
+// TODO (breaking change) deprecate in the next major release, use opentracing.Tag instead.
+func NewTag(key string, value interface{}) Tag {
+	return Tag{key: key, value: value}
+}
+
 // SetOperationName sets or changes the operation name.
 func (s *Span) SetOperationName(operationName string) opentracing.Span {
 	s.Lock()
-	defer s.Unlock()
-	if s.context.IsSampled() {
-		s.operationName = operationName
+	s.operationName = operationName
+	s.Unlock()
+	if !s.isSamplingFinalized() {
+		decision := s.tracer.sampler.OnSetOperationName(s, operationName)
+		s.applySamplingDecision(decision, true)
 	}
 	s.observer.OnSetOperationName(operationName)
 	return s
@@ -84,14 +93,24 @@ func (s *Span) SetOperationName(operationName string) opentracing.Span {
 
 // SetTag implements SetTag() of opentracing.Span
 func (s *Span) SetTag(key string, value interface{}) opentracing.Span {
+	return s.setTagInternal(key, value, true)
+}
+
+func (s *Span) setTagInternal(key string, value interface{}, lock bool) opentracing.Span {
 	s.observer.OnSetTag(key, value)
 	if key == string(ext.SamplingPriority) && !setSamplingPriority(s, value) {
 		return s
 	}
-	s.Lock()
-	defer s.Unlock()
-	if s.context.IsSampled() {
-		s.setTagNoLocking(key, value)
+	if !s.isSamplingFinalized() {
+		decision := s.tracer.sampler.OnSetTag(s, key, value)
+		s.applySamplingDecision(decision, lock)
+	}
+	if s.isWriteable() {
+		if lock {
+			s.Lock()
+			defer s.Unlock()
+		}
+		s.appendTagNoLocking(key, value)
 	}
 	return s
 }
@@ -121,14 +140,38 @@ func (s *Span) Duration() time.Duration {
 func (s *Span) Tags() opentracing.Tags {
 	s.Lock()
 	defer s.Unlock()
-	var result = make(opentracing.Tags)
+	var result = make(opentracing.Tags, len(s.tags))
 	for _, tag := range s.tags {
 		result[tag.key] = tag.value
 	}
 	return result
 }
 
-func (s *Span) setTagNoLocking(key string, value interface{}) {
+// Logs returns micro logs for span
+func (s *Span) Logs() []opentracing.LogRecord {
+	s.Lock()
+	defer s.Unlock()
+
+	return append([]opentracing.LogRecord(nil), s.logs...)
+}
+
+// References returns references for this span
+func (s *Span) References() []opentracing.SpanReference {
+	s.Lock()
+	defer s.Unlock()
+
+	if s.references == nil || len(s.references) == 0 {
+		return nil
+	}
+
+	result := make([]opentracing.SpanReference, len(s.references))
+	for i, r := range s.references {
+		result[i] = opentracing.SpanReference{Type: r.Type, ReferencedContext: r.Context}
+	}
+	return result
+}
+
+func (s *Span) appendTagNoLocking(key string, value interface{}) {
 	s.tags = append(s.tags, Tag{key: key, value: value})
 }
 
@@ -148,7 +191,7 @@ func (s *Span) logFieldsNoLocking(fields ...log.Field) {
 		Fields:    fields,
 		Timestamp: time.Now(),
 	}
-	s.appendLog(lr)
+	s.appendLogNoLocking(lr)
 }
 
 // LogKV implements opentracing.Span API
@@ -185,12 +228,12 @@ func (s *Span) Log(ld opentracing.LogData) {
 		if ld.Timestamp.IsZero() {
 			ld.Timestamp = s.tracer.timeNow()
 		}
-		s.appendLog(ld.ToLogRecord())
+		s.appendLogNoLocking(ld.ToLogRecord())
 	}
 }
 
 // this function should only be called while holding a Write lock
-func (s *Span) appendLog(lr opentracing.LogRecord) {
+func (s *Span) appendLogNoLocking(lr opentracing.LogRecord) {
 	// TODO add logic to limit number of logs per span (issue #46)
 	s.logs = append(s.logs, lr)
 }
@@ -224,17 +267,25 @@ func (s *Span) FinishWithOptions(options opentracing.FinishOptions) {
 	}
 	s.observer.OnFinish(options)
 	s.Lock()
+	s.duration = options.FinishTime.Sub(s.startTime)
+	s.Unlock()
+	if !s.isSamplingFinalized() {
+		decision := s.tracer.sampler.OnFinishSpan(s)
+		s.applySamplingDecision(decision, true)
+	}
 	if s.context.IsSampled() {
-		s.duration = options.FinishTime.Sub(s.startTime)
-		// Note: bulk logs are not subject to maxLogsPerSpan limit
-		if options.LogRecords != nil {
-			s.logs = append(s.logs, options.LogRecords...)
-		}
-		for _, ld := range options.BulkLogData {
-			s.logs = append(s.logs, ld.ToLogRecord())
+		if len(options.LogRecords) > 0 || len(options.BulkLogData) > 0 {
+			s.Lock()
+			// Note: bulk logs are not subject to maxLogsPerSpan limit
+			if options.LogRecords != nil {
+				s.logs = append(s.logs, options.LogRecords...)
+			}
+			for _, ld := range options.BulkLogData {
+				s.logs = append(s.logs, ld.ToLogRecord())
+			}
+			s.Unlock()
 		}
 	}
-	s.Unlock()
 	// call reportSpan even for non-sampled traces, to return span to the pool
 	// and update metrics counter
 	s.tracer.reportSpan(s)
@@ -300,23 +351,62 @@ func (s *Span) serviceName() string {
 	return s.tracer.serviceName
 }
 
+func (s *Span) applySamplingDecision(decision SamplingDecision, lock bool) {
+	if !decision.Retryable {
+		s.context.samplingState.setFinal()
+	}
+	if decision.Sample {
+		s.context.samplingState.setSampled()
+		if len(decision.Tags) > 0 {
+			if lock {
+				s.Lock()
+				defer s.Unlock()
+			}
+			for _, tag := range decision.Tags {
+				s.appendTagNoLocking(tag.key, tag.value)
+			}
+		}
+	}
+}
+
+// Span can be written to if it is sampled or the sampling decision has not been finalized.
+func (s *Span) isWriteable() bool {
+	state := s.context.samplingState
+	return !state.isFinal() || state.isSampled()
+}
+
+func (s *Span) isSamplingFinalized() bool {
+	return s.context.samplingState.isFinal()
+}
+
 // setSamplingPriority returns true if the flag was updated successfully, false otherwise.
+// The behavior of setSamplingPriority is surprising
+// If noDebugFlagOnForcedSampling is set
+//     setSamplingPriority(span, 1) always sets only flagSampled
+// If noDebugFlagOnForcedSampling is unset, and isDebugAllowed passes
+//     setSamplingPriority(span, 1) sets both flagSampled and flagDebug
+// However,
+//     setSamplingPriority(span, 0) always only resets flagSampled
+//
+// This means that doing a setSamplingPriority(span, 1) followed by setSamplingPriority(span, 0) can
+// leave flagDebug set
 func setSamplingPriority(s *Span, value interface{}) bool {
 	val, ok := value.(uint16)
 	if !ok {
 		return false
 	}
-	s.Lock()
-	defer s.Unlock()
 	if val == 0 {
-		s.context.flags = s.context.flags & (^flagSampled)
+		s.context.samplingState.unsetSampled()
+		s.context.samplingState.setFinal()
 		return true
 	}
 	if s.tracer.options.noDebugFlagOnForcedSampling {
-		s.context.flags = s.context.flags | flagSampled
+		s.context.samplingState.setSampled()
+		s.context.samplingState.setFinal()
 		return true
 	} else if s.tracer.isDebugAllowed(s.operationName) {
-		s.context.flags = s.context.flags | flagDebug | flagSampled
+		s.context.samplingState.setDebugAndSampled()
+		s.context.samplingState.setFinal()
 		return true
 	}
 	return false
@@ -326,5 +416,5 @@ func setSamplingPriority(s *Span, value interface{}) bool {
 func EnableFirehose(s *Span) {
 	s.Lock()
 	defer s.Unlock()
-	s.context.flags |= flagFirehose
+	s.context.samplingState.setFirehose()
 }
diff --git a/vendor/github.com/uber/jaeger-client-go/context.go b/vendor/github.com/uber/jaeger-client-go/span_context.go
index 43553655a..b7230abfe 100644
--- a/vendor/github.com/uber/jaeger-client-go/context.go
+++ b/vendor/github.com/uber/jaeger-client-go/span_context.go
@@ -19,12 +19,15 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
+	"sync"
+
+	"go.uber.org/atomic"
 )
 
 const (
-	flagSampled  = byte(1)
-	flagDebug    = byte(2)
-	flagFirehose = byte(8)
+	flagSampled  = 1
+	flagDebug    = 2
+	flagFirehose = 8
 )
 
 var (
@@ -56,9 +59,6 @@ type SpanContext struct {
 	// Should be 0 if the current span is a root span.
 	parentID SpanID
 
-	// flags is a bitmap containing such bits as 'sampled' and 'debug'.
-	flags byte
-
 	// Distributed Context baggage. The is a snapshot in time.
 	baggage map[string]string
 
@@ -67,6 +67,102 @@ type SpanContext struct {
 	//
 	// See JaegerDebugHeader in constants.go
 	debugID string
+
+	// samplingState is shared across all spans
+	samplingState *samplingState
+
+	// remote indicates that span context represents a remote parent
+	remote bool
+}
+
+type samplingState struct {
+	// Span context's state flags that are propagated across processes. Only lower 8 bits are used.
+	// We use an int32 instead of byte to be able to use CAS operations.
+	stateFlags atomic.Int32
+
+	// When state is not final, sampling will be retried on other span write operations,
+	// like SetOperationName / SetTag, and the spans will remain writable.
+	final atomic.Bool
+
+	// localRootSpan stores the SpanID of the first span created in this process for a given trace.
+	localRootSpan SpanID
+
+	// extendedState allows samplers to keep intermediate state.
+	// The keys and values in this map are completely opaque: interface{} -> interface{}.
+	extendedState sync.Map
+}
+
+func (s *samplingState) isLocalRootSpan(id SpanID) bool {
+	return id == s.localRootSpan
+}
+
+func (s *samplingState) setFlag(newFlag int32) {
+	swapped := false
+	for !swapped {
+		old := s.stateFlags.Load()
+		swapped = s.stateFlags.CAS(old, old|newFlag)
+	}
+}
+
+func (s *samplingState) unsetFlag(newFlag int32) {
+	swapped := false
+	for !swapped {
+		old := s.stateFlags.Load()
+		swapped = s.stateFlags.CAS(old, old&^newFlag)
+	}
+}
+
+func (s *samplingState) setSampled() {
+	s.setFlag(flagSampled)
+}
+
+func (s *samplingState) unsetSampled() {
+	s.unsetFlag(flagSampled)
+}
+
+func (s *samplingState) setDebugAndSampled() {
+	s.setFlag(flagDebug | flagSampled)
+}
+
+func (s *samplingState) setFirehose() {
+	s.setFlag(flagFirehose)
+}
+
+func (s *samplingState) setFlags(flags byte) {
+	s.stateFlags.Store(int32(flags))
+}
+
+func (s *samplingState) setFinal() {
+	s.final.Store(true)
+}
+
+func (s *samplingState) flags() byte {
+	return byte(s.stateFlags.Load())
+}
+
+func (s *samplingState) isSampled() bool {
+	return s.stateFlags.Load()&flagSampled == flagSampled
+}
+
+func (s *samplingState) isDebug() bool {
+	return s.stateFlags.Load()&flagDebug == flagDebug
+}
+
+func (s *samplingState) isFirehose() bool {
+	return s.stateFlags.Load()&flagFirehose == flagFirehose
+}
+
+func (s *samplingState) isFinal() bool {
+	return s.final.Load()
+}
+
+func (s *samplingState) extendedStateForKey(key interface{}, initValue func() interface{}) interface{} {
+	if value, ok := s.extendedState.Load(key); ok {
+		return value
+	}
+	value := initValue()
+	value, _ = s.extendedState.LoadOrStore(key, value)
+	return value
 }
 
 // ForeachBaggageItem implements ForeachBaggageItem() of opentracing.SpanContext
@@ -81,17 +177,28 @@ func (c SpanContext) ForeachBaggageItem(handler func(k, v string) bool) {
 // IsSampled returns whether this trace was chosen for permanent storage
 // by the sampling mechanism of the tracer.
 func (c SpanContext) IsSampled() bool {
-	return (c.flags & flagSampled) == flagSampled
+	return c.samplingState.isSampled()
 }
 
 // IsDebug indicates whether sampling was explicitly requested by the service.
 func (c SpanContext) IsDebug() bool {
-	return (c.flags & flagDebug) == flagDebug
+	return c.samplingState.isDebug()
+}
+
+// IsSamplingFinalized indicates whether the sampling decision has been finalized.
+func (c SpanContext) IsSamplingFinalized() bool {
+	return c.samplingState.isFinal()
 }
 
 // IsFirehose indicates whether the firehose flag was set
 func (c SpanContext) IsFirehose() bool {
-	return (c.flags & flagFirehose) == flagFirehose
+	return c.samplingState.isFirehose()
+}
+
+// ExtendedSamplingState returns the custom state object for a given key. If the value for this key does not exist,
+// it is initialized via initValue function. This state can be used by samplers (e.g. x.PrioritySampler).
+func (c SpanContext) ExtendedSamplingState(key interface{}, initValue func() interface{}) interface{} {
+	return c.samplingState.extendedStateForKey(key, initValue)
 }
 
 // IsValid indicates whether this context actually represents a valid trace.
@@ -99,11 +206,16 @@ func (c SpanContext) IsValid() bool {
 	return c.traceID.IsValid() && c.spanID != 0
 }
 
+// SetFirehose enables firehose mode for this trace.
+func (c SpanContext) SetFirehose() {
+	c.samplingState.setFirehose()
+}
+
 func (c SpanContext) String() string {
 	if c.traceID.High == 0 {
-		return fmt.Sprintf("%x:%x:%x:%x", c.traceID.Low, uint64(c.spanID), uint64(c.parentID), c.flags)
+		return fmt.Sprintf("%x:%x:%x:%x", c.traceID.Low, uint64(c.spanID), uint64(c.parentID), c.samplingState.stateFlags.Load())
 	}
-	return fmt.Sprintf("%x%016x:%x:%x:%x", c.traceID.High, c.traceID.Low, uint64(c.spanID), uint64(c.parentID), c.flags)
+	return fmt.Sprintf("%x%016x:%x:%x:%x", c.traceID.High, c.traceID.Low, uint64(c.spanID), uint64(c.parentID), c.samplingState.stateFlags.Load())
 }
 
 // ContextFromString reconstructs the Context encoded in a string
@@ -130,7 +242,8 @@ func ContextFromString(value string) (SpanContext, error) {
 	if err != nil {
 		return emptyContext, err
 	}
-	context.flags = byte(flags)
+	context.samplingState = &samplingState{}
+	context.samplingState.setFlags(byte(flags))
 	return context, nil
 }
 
@@ -149,18 +262,24 @@ func (c SpanContext) ParentID() SpanID {
 	return c.parentID
 }
 
+// Flags returns the bitmap containing such bits as 'sampled' and 'debug'.
+func (c SpanContext) Flags() byte {
+	return c.samplingState.flags()
+}
+
 // NewSpanContext creates a new instance of SpanContext
 func NewSpanContext(traceID TraceID, spanID, parentID SpanID, sampled bool, baggage map[string]string) SpanContext {
-	flags := byte(0)
+	samplingState := &samplingState{}
 	if sampled {
-		flags = flagSampled
+		samplingState.setSampled()
 	}
+
 	return SpanContext{
-		traceID:  traceID,
-		spanID:   spanID,
-		parentID: parentID,
-		flags:    flags,
-		baggage:  baggage}
+		traceID:       traceID,
+		spanID:        spanID,
+		parentID:      parentID,
+		samplingState: samplingState,
+		baggage:       baggage}
 }
 
 // CopyFrom copies data from ctx into this context, including span identity and baggage.
@@ -169,7 +288,7 @@ func (c *SpanContext) CopyFrom(ctx *SpanContext) {
 	c.traceID = ctx.traceID
 	c.spanID = ctx.spanID
 	c.parentID = ctx.parentID
-	c.flags = ctx.flags
+	c.samplingState = ctx.samplingState
 	if l := len(ctx.baggage); l > 0 {
 		c.baggage = make(map[string]string, l)
 		for k, v := range ctx.baggage {
@@ -193,7 +312,7 @@ func (c SpanContext) WithBaggageItem(key, value string) SpanContext {
 		newBaggage[key] = value
 	}
 	// Use positional parameters so the compiler will help catch new fields.
-	return SpanContext{c.traceID, c.spanID, c.parentID, c.flags, newBaggage, ""}
+	return SpanContext{c.traceID, c.spanID, c.parentID, newBaggage, "", c.samplingState, c.remote}
 }
 
 // isDebugIDContainerOnly returns true when the instance of the context is only
diff --git a/vendor/github.com/uber/jaeger-client-go/tracer.go b/vendor/github.com/uber/jaeger-client-go/tracer.go
index 745a0c38a..f03372dc7 100644
--- a/vendor/github.com/uber/jaeger-client-go/tracer.go
+++ b/vendor/github.com/uber/jaeger-client-go/tracer.go
@@ -38,7 +38,7 @@ type Tracer struct {
 	serviceName string
 	hostIPv4    uint32 // this is for zipkin endpoint conversion
 
-	sampler  Sampler
+	sampler  SamplerV2
 	reporter Reporter
 	metrics  Metrics
 	logger   log.Logger
@@ -74,6 +74,7 @@ type Tracer struct {
 // NewTracer creates Tracer implementation that reports tracing to Jaeger.
 // The returned io.Closer can be used in shutdown hooks to ensure that the internal
 // queue of the Reporter is drained and all buffered spans are submitted to collectors.
+// TODO (breaking change) return *Tracer only, without closer.
 func NewTracer(
 	serviceName string,
 	sampler Sampler,
@@ -82,7 +83,7 @@ func NewTracer(
 ) (opentracing.Tracer, io.Closer) {
 	t := &Tracer{
 		serviceName:   serviceName,
-		sampler:       sampler,
+		sampler:       samplerV1toV2(sampler),
 		reporter:      reporter,
 		injectors:     make(map[interface{}]Injector),
 		extractors:    make(map[interface{}]Extractor),
@@ -261,7 +262,7 @@ func (t *Tracer) startSpanWithOptions(
 		rpcServer = (v == ext.SpanKindRPCServerEnum || v == string(ext.SpanKindRPCServerEnum))
 	}
 
-	var samplerTags []Tag
+	var internalTags []Tag
 	newTrace := false
 	if !isSelfRef {
 		if !hasParent || !parent.IsValid() {
@@ -272,13 +273,12 @@ func (t *Tracer) startSpanWithOptions(
 			}
 			ctx.spanID = SpanID(ctx.traceID.Low)
 			ctx.parentID = 0
-			ctx.flags = byte(0)
+			ctx.samplingState = &samplingState{
+				localRootSpan: ctx.spanID,
+			}
 			if hasParent && parent.isDebugIDContainerOnly() && t.isDebugAllowed(operationName) {
-				ctx.flags |= (flagSampled | flagDebug)
-				samplerTags = []Tag{{key: JaegerDebugHeader, value: parent.debugID}}
-			} else if sampled, tags := t.sampler.IsSampled(ctx.traceID, operationName); sampled {
-				ctx.flags |= flagSampled
-				samplerTags = tags
+				ctx.samplingState.setDebugAndSampled()
+				internalTags = append(internalTags, Tag{key: JaegerDebugHeader, value: parent.debugID})
 			}
 		} else {
 			ctx.traceID = parent.traceID
@@ -290,7 +290,11 @@ func (t *Tracer) startSpanWithOptions(
 				ctx.spanID = SpanID(t.randomID())
 				ctx.parentID = parent.spanID
 			}
-			ctx.flags = parent.flags
+			ctx.samplingState = parent.samplingState
+			if parent.remote {
+				ctx.samplingState.setFinal()
+				ctx.samplingState.localRootSpan = ctx.spanID
+			}
 		}
 		if hasParent {
 			// copy baggage items
@@ -305,17 +309,30 @@ func (t *Tracer) startSpanWithOptions(
 
 	sp := t.newSpan()
 	sp.context = ctx
+	sp.tracer = t
+	sp.operationName = operationName
+	sp.startTime = options.StartTime
+	sp.duration = 0
+	sp.references = references
+	sp.firstInProcess = rpcServer || sp.context.parentID == 0
+
+	if !sp.isSamplingFinalized() {
+		decision := t.sampler.OnCreateSpan(sp)
+		sp.applySamplingDecision(decision, false)
+	}
 	sp.observer = t.observer.OnStartSpan(sp, operationName, options)
-	return t.startSpanInternal(
-		sp,
-		operationName,
-		options.StartTime,
-		samplerTags,
-		options.Tags,
-		newTrace,
-		rpcServer,
-		references,
-	)
+
+	if tagsTotalLength := len(options.Tags) + len(internalTags); tagsTotalLength > 0 {
+		if sp.tags == nil || cap(sp.tags) < tagsTotalLength {
+			sp.tags = make([]Tag, 0, tagsTotalLength)
+		}
+		sp.tags = append(sp.tags, internalTags...)
+		for k, v := range options.Tags {
+			sp.setTagInternal(k, v, false)
+		}
+	}
+	t.emitNewSpanMetrics(sp, newTrace)
+	return sp
 }
 
 // Inject implements Inject() method of opentracing.Tracer
@@ -340,6 +357,7 @@ func (t *Tracer) Extract(
 		if err != nil {
 			return nil, err // ensure returned spanCtx is nil
 		}
+		spanCtx.remote = true
 		return spanCtx, nil
 	}
 	return nil, opentracing.ErrUnsupportedFormat
@@ -350,10 +368,10 @@ func (t *Tracer) Close() error {
 	t.reporter.Close()
 	t.sampler.Close()
 	if mgr, ok := t.baggageRestrictionManager.(io.Closer); ok {
-		mgr.Close()
+		_ = mgr.Close()
 	}
 	if throttler, ok := t.debugThrottler.(io.Closer); ok {
-		throttler.Close()
+		_ = throttler.Close()
 	}
 	return nil
 }
@@ -368,6 +386,7 @@ func (t *Tracer) Tags() []opentracing.Tag {
 }
 
 // getTag returns the value of specific tag, if not exists, return nil.
+// TODO only used by tests, move there.
 func (t *Tracer) getTag(key string) (interface{}, bool) {
 	for _, tag := range t.tags {
 		if tag.key == key {
@@ -383,41 +402,21 @@ func (t *Tracer) newSpan() *Span {
 	return t.spanAllocator.Get()
 }
 
-func (t *Tracer) startSpanInternal(
-	sp *Span,
-	operationName string,
-	startTime time.Time,
-	internalTags []Tag,
-	tags opentracing.Tags,
-	newTrace bool,
-	rpcServer bool,
-	references []Reference,
-) *Span {
-	sp.tracer = t
-	sp.operationName = operationName
-	sp.startTime = startTime
-	sp.duration = 0
-	sp.references = references
-	sp.firstInProcess = rpcServer || sp.context.parentID == 0
-	if len(tags) > 0 || len(internalTags) > 0 {
-		sp.tags = make([]Tag, len(internalTags), len(tags)+len(internalTags))
-		copy(sp.tags, internalTags)
-		for k, v := range tags {
-			sp.observer.OnSetTag(k, v)
-			if k == string(ext.SamplingPriority) && !setSamplingPriority(sp, v) {
-				continue
-			}
-			sp.setTagNoLocking(k, v)
+// emitNewSpanMetrics generates metrics on the number of started spans and traces.
+// newTrace param: we cannot simply check for parentID==0 because in Zipkin model the
+// server-side RPC span has the exact same trace/span/parent IDs as the
+// calling client-side span, but obviously the server side span is
+// no longer a root span of the trace.
+func (t *Tracer) emitNewSpanMetrics(sp *Span, newTrace bool) {
+	if !sp.isSamplingFinalized() {
+		t.metrics.SpansStartedDelayedSampling.Inc(1)
+		if newTrace {
+			t.metrics.TracesStartedDelayedSampling.Inc(1)
 		}
-	}
-	// emit metrics
-	if sp.context.IsSampled() {
+		// joining a trace is not possible, because sampling decision inherited from upstream is final
+	} else if sp.context.IsSampled() {
 		t.metrics.SpansStartedSampled.Inc(1)
 		if newTrace {
-			// We cannot simply check for parentID==0 because in Zipkin model the
-			// server-side RPC span has the exact same trace/span/parent IDs as the
-			// calling client-side span, but obviously the server side span is
-			// no longer a root span of the trace.
 			t.metrics.TracesStartedSampled.Inc(1)
 		} else if sp.firstInProcess {
 			t.metrics.TracesJoinedSampled.Inc(1)
@@ -430,15 +429,20 @@ func (t *Tracer) startSpanInternal(
 			t.metrics.TracesJoinedNotSampled.Inc(1)
 		}
 	}
-	return sp
 }
 
 func (t *Tracer) reportSpan(sp *Span) {
-	t.metrics.SpansFinished.Inc(1)
+	if !sp.isSamplingFinalized() {
+		t.metrics.SpansFinishedDelayedSampling.Inc(1)
+	} else if sp.context.IsSampled() {
+		t.metrics.SpansFinishedSampled.Inc(1)
+	} else {
+		t.metrics.SpansFinishedNotSampled.Inc(1)
+	}
 
-	// Note: if the reporter is processing Span asynchronously need to Retain() it
-	// otherwise, in the racing condition will be rewritten span data before it will be sent
-	// * To remove object use method span.Release()
+	// Note: if the reporter is processing Span asynchronously then it needs to Retain() the span,
+	// and then Release() it when no longer needed.
+	// Otherwise, the span may be reused for another trace and its data may be overwritten.
 	if sp.context.IsSampled() {
 		t.reporter.Report(sp)
 	}
@@ -466,6 +470,11 @@ func (t *Tracer) isDebugAllowed(operation string) bool {
 	return t.debugThrottler.IsAllowed(operation)
 }
 
+// Sampler returns the sampler given to the tracer at creation.
+func (t *Tracer) Sampler() SamplerV2 {
+	return t.sampler
+}
+
 // SelfRef creates an opentracing compliant SpanReference from a jaeger
 // SpanContext. This is a factory function in order to encapsulate jaeger specific
 // types.
diff --git a/vendor/github.com/uber/jaeger-client-go/utils/rate_limiter.go b/vendor/github.com/uber/jaeger-client-go/utils/rate_limiter.go
index 1b8db9758..bf2f13165 100644
--- a/vendor/github.com/uber/jaeger-client-go/utils/rate_limiter.go
+++ b/vendor/github.com/uber/jaeger-client-go/utils/rate_limiter.go
@@ -20,22 +20,15 @@ import (
 )
 
 // RateLimiter is a filter used to check if a message that is worth itemCost units is within the rate limits.
+//
+// TODO (breaking change) remove this interface in favor of public struct below
+//
+// Deprecated, use ReconfigurableRateLimiter.
 type RateLimiter interface {
 	CheckCredit(itemCost float64) bool
 }
 
-type rateLimiter struct {
-	sync.Mutex
-
-	creditsPerSecond float64
-	balance          float64
-	maxBalance       float64
-	lastTick         time.Time
-
-	timeNow func() time.Time
-}
-
-// NewRateLimiter creates a new rate limiter based on leaky bucket algorithm, formulated in terms of a
+// ReconfigurableRateLimiter is a rate limiter based on leaky bucket algorithm, formulated in terms of a
 // credits balance that is replenished every time CheckCredit() method is called (tick) by the amount proportional
 // to the time elapsed since the last tick, up to max of creditsPerSecond. A call to CheckCredit() takes a cost
 // of an item we want to pay with the balance. If the balance exceeds the cost of the item, the item is "purchased"
@@ -47,31 +40,73 @@ type rateLimiter struct {
 //
 // It can also be used to limit the rate of traffic in bytes, by setting creditsPerSecond to desired throughput
 // as bytes/second, and calling CheckCredit() with the actual message size.
-func NewRateLimiter(creditsPerSecond, maxBalance float64) RateLimiter {
-	return &rateLimiter{
+//
+// TODO (breaking change) rename to RateLimiter once the interface is removed
+type ReconfigurableRateLimiter struct {
+	lock sync.Mutex
+
+	creditsPerSecond float64
+	balance          float64
+	maxBalance       float64
+	lastTick         time.Time
+
+	timeNow func() time.Time
+}
+
+// NewRateLimiter creates a new ReconfigurableRateLimiter.
+func NewRateLimiter(creditsPerSecond, maxBalance float64) *ReconfigurableRateLimiter {
+	return &ReconfigurableRateLimiter{
 		creditsPerSecond: creditsPerSecond,
 		balance:          maxBalance,
 		maxBalance:       maxBalance,
 		lastTick:         time.Now(),
-		timeNow:          time.Now}
+		timeNow:          time.Now,
+	}
 }
 
-func (b *rateLimiter) CheckCredit(itemCost float64) bool {
-	b.Lock()
-	defer b.Unlock()
-	// calculate how much time passed since the last tick, and update current tick
-	currentTime := b.timeNow()
-	elapsedTime := currentTime.Sub(b.lastTick)
-	b.lastTick = currentTime
-	// calculate how much credit have we accumulated since the last tick
-	b.balance += elapsedTime.Seconds() * b.creditsPerSecond
-	if b.balance > b.maxBalance {
-		b.balance = b.maxBalance
-	}
+// CheckCredit tries to reduce the current balance by itemCost provided that the current balance
+// is not lest than itemCost.
+func (rl *ReconfigurableRateLimiter) CheckCredit(itemCost float64) bool {
+	rl.lock.Lock()
+	defer rl.lock.Unlock()
+
 	// if we have enough credits to pay for current item, then reduce balance and allow
-	if b.balance >= itemCost {
-		b.balance -= itemCost
+	if rl.balance >= itemCost {
+		rl.balance -= itemCost
+		return true
+	}
+	// otherwise check if balance can be increased due to time elapsed, and try again
+	rl.updateBalance()
+	if rl.balance >= itemCost {
+		rl.balance -= itemCost
 		return true
 	}
 	return false
 }
+
+// updateBalance recalculates current balance based on time elapsed. Must be called while holding a lock.
+func (rl *ReconfigurableRateLimiter) updateBalance() {
+	// calculate how much time passed since the last tick, and update current tick
+	currentTime := rl.timeNow()
+	elapsedTime := currentTime.Sub(rl.lastTick)
+	rl.lastTick = currentTime
+	// calculate how much credit have we accumulated since the last tick
+	rl.balance += elapsedTime.Seconds() * rl.creditsPerSecond
+	if rl.balance > rl.maxBalance {
+		rl.balance = rl.maxBalance
+	}
+}
+
+// Update changes the main parameters of the rate limiter in-place, while retaining
+// the current accumulated balance (pro-rated to the new maxBalance value). Using this method
+// instead of creating a new rate limiter helps to avoid thundering herd when sampling
+// strategies are updated.
+func (rl *ReconfigurableRateLimiter) Update(creditsPerSecond, maxBalance float64) {
+	rl.lock.Lock()
+	defer rl.lock.Unlock()
+
+	rl.updateBalance() // get up to date balance
+	rl.balance = rl.balance * maxBalance / rl.maxBalance
+	rl.creditsPerSecond = creditsPerSecond
+	rl.maxBalance = maxBalance
+}
diff --git a/vendor/github.com/uber/jaeger-client-go/zipkin.go b/vendor/github.com/uber/jaeger-client-go/zipkin.go
index 636952b7f..98cab4b6e 100644
--- a/vendor/github.com/uber/jaeger-client-go/zipkin.go
+++ b/vendor/github.com/uber/jaeger-client-go/zipkin.go
@@ -55,7 +55,7 @@ func (p *zipkinPropagator) Inject(
 	carrier.SetTraceID(ctx.TraceID().Low) // TODO this cannot work with 128bit IDs
 	carrier.SetSpanID(uint64(ctx.SpanID()))
 	carrier.SetParentID(uint64(ctx.ParentID()))
-	carrier.SetFlags(ctx.flags)
+	carrier.SetFlags(ctx.samplingState.flags())
 	return nil
 }
 
@@ -71,6 +71,7 @@ func (p *zipkinPropagator) Extract(abstractCarrier interface{}) (SpanContext, er
 	ctx.traceID.Low = carrier.TraceID()
 	ctx.spanID = SpanID(carrier.SpanID())
 	ctx.parentID = SpanID(carrier.ParentID())
-	ctx.flags = carrier.Flags()
+	ctx.samplingState = &samplingState{}
+	ctx.samplingState.setFlags(carrier.Flags())
 	return ctx, nil
 }
diff --git a/vendor/go.uber.org/atomic/.codecov.yml b/vendor/go.uber.org/atomic/.codecov.yml
new file mode 100644
index 000000000..6d4d1be7b
--- /dev/null
+++ b/vendor/go.uber.org/atomic/.codecov.yml
@@ -0,0 +1,15 @@
+coverage:
+  range: 80..100
+  round: down
+  precision: 2
+
+  status:
+    project:                   # measuring the overall project coverage
+      default:                 # context, you can create multiple ones with custom titles
+        enabled: yes           # must be yes|true to enable this status
+        target: 100            # specify the target coverage for each commit status
+                               #   option: "auto" (must increase from parent commit or pull request base)
+                               #   option: "X%" a static target percentage to hit
+        if_not_found: success  # if parent is not found report status as success, error, or failure
+        if_ci_failed: error    # if ci fails report status as success, error, or failure
+
diff --git a/vendor/go.uber.org/atomic/.gitignore b/vendor/go.uber.org/atomic/.gitignore
new file mode 100644
index 000000000..0a4504f11
--- /dev/null
+++ b/vendor/go.uber.org/atomic/.gitignore
@@ -0,0 +1,11 @@
+.DS_Store
+/vendor
+/cover
+cover.out
+lint.log
+
+# Binaries
+*.test
+
+# Profiling output
+*.prof
diff --git a/vendor/go.uber.org/atomic/.travis.yml b/vendor/go.uber.org/atomic/.travis.yml
new file mode 100644
index 000000000..0f3769e5f
--- /dev/null
+++ b/vendor/go.uber.org/atomic/.travis.yml
@@ -0,0 +1,27 @@
+sudo: false
+language: go
+go_import_path: go.uber.org/atomic
+
+go:
+  - 1.11.x
+  - 1.12.x
+
+matrix:
+  include:
+  - go: 1.12.x
+    env: NO_TEST=yes LINT=yes
+
+cache:
+  directories:
+    - vendor
+
+install:
+  - make install_ci
+
+script:
+  - test -n "$NO_TEST" || make test_ci
+  - test -n "$NO_TEST" || scripts/test-ubergo.sh
+  - test -z "$LINT" || make install_lint lint
+
+after_success:
+  - bash <(curl -s https://codecov.io/bash)
diff --git a/vendor/go.uber.org/atomic/LICENSE.txt b/vendor/go.uber.org/atomic/LICENSE.txt
new file mode 100644
index 000000000..8765c9fbc
--- /dev/null
+++ b/vendor/go.uber.org/atomic/LICENSE.txt
@@ -0,0 +1,19 @@
+Copyright (c) 2016 Uber Technologies, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/vendor/go.uber.org/atomic/Makefile b/vendor/go.uber.org/atomic/Makefile
new file mode 100644
index 000000000..1ef263075
--- /dev/null
+++ b/vendor/go.uber.org/atomic/Makefile
@@ -0,0 +1,51 @@
+# Many Go tools take file globs or directories as arguments instead of packages.
+PACKAGE_FILES ?= *.go
+
+# For pre go1.6
+export GO15VENDOREXPERIMENT=1
+
+
+.PHONY: build
+build:
+	go build -i ./...
+
+
+.PHONY: install
+install:
+	glide --version || go get github.com/Masterminds/glide
+	glide install
+
+
+.PHONY: test
+test:
+	go test -cover -race ./...
+
+
+.PHONY: install_ci
+install_ci: install
+	go get github.com/wadey/gocovmerge
+	go get github.com/mattn/goveralls
+	go get golang.org/x/tools/cmd/cover
+
+.PHONY: install_lint
+install_lint:
+	go get golang.org/x/lint/golint
+
+
+.PHONY: lint
+lint:
+	@rm -rf lint.log
+	@echo "Checking formatting..."
+	@gofmt -d -s $(PACKAGE_FILES) 2>&1 | tee lint.log
+	@echo "Checking vet..."
+	@go vet ./... 2>&1 | tee -a lint.log;)
+	@echo "Checking lint..."
+	@golint $$(go list ./...) 2>&1 | tee -a lint.log
+	@echo "Checking for unresolved FIXMEs..."
+	@git grep -i fixme | grep -v -e vendor -e Makefile | tee -a lint.log
+	@[ ! -s lint.log ]
+
+
+.PHONY: test_ci
+test_ci: install_ci build
+	./scripts/cover.sh $(shell go list $(PACKAGES))
diff --git a/vendor/go.uber.org/atomic/README.md b/vendor/go.uber.org/atomic/README.md
new file mode 100644
index 000000000..62eb8e576
--- /dev/null
+++ b/vendor/go.uber.org/atomic/README.md
@@ -0,0 +1,36 @@
+# atomic [![GoDoc][doc-img]][doc] [![Build Status][ci-img]][ci] [![Coverage Status][cov-img]][cov] [![Go Report Card][reportcard-img]][reportcard]
+
+Simple wrappers for primitive types to enforce atomic access.
+
+## Installation
+`go get -u go.uber.org/atomic`
+
+## Usage
+The standard library's `sync/atomic` is powerful, but it's easy to forget which
+variables must be accessed atomically. `go.uber.org/atomic` preserves all the
+functionality of the standard library, but wraps the primitive types to
+provide a safer, more convenient API.
+
+```go
+var atom atomic.Uint32
+atom.Store(42)
+atom.Sub(2)
+atom.CAS(40, 11)
+```
+
+See the [documentation][doc] for a complete API specification.
+
+## Development Status
+Stable.
+
+___
+Released under the [MIT License](LICENSE.txt).
+
+[doc-img]: https://godoc.org/github.com/uber-go/atomic?status.svg
+[doc]: https://godoc.org/go.uber.org/atomic
+[ci-img]: https://travis-ci.com/uber-go/atomic.svg?branch=master
+[ci]: https://travis-ci.com/uber-go/atomic
+[cov-img]: https://codecov.io/gh/uber-go/atomic/branch/master/graph/badge.svg
+[cov]: https://codecov.io/gh/uber-go/atomic
+[reportcard-img]: https://goreportcard.com/badge/go.uber.org/atomic
+[reportcard]: https://goreportcard.com/report/go.uber.org/atomic
diff --git a/vendor/go.uber.org/atomic/atomic.go b/vendor/go.uber.org/atomic/atomic.go
new file mode 100644
index 000000000..1db6849fc
--- /dev/null
+++ b/vendor/go.uber.org/atomic/atomic.go
@@ -0,0 +1,351 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package atomic provides simple wrappers around numerics to enforce atomic
+// access.
+package atomic
+
+import (
+	"math"
+	"sync/atomic"
+	"time"
+)
+
+// Int32 is an atomic wrapper around an int32.
+type Int32 struct{ v int32 }
+
+// NewInt32 creates an Int32.
+func NewInt32(i int32) *Int32 {
+	return &Int32{i}
+}
+
+// Load atomically loads the wrapped value.
+func (i *Int32) Load() int32 {
+	return atomic.LoadInt32(&i.v)
+}
+
+// Add atomically adds to the wrapped int32 and returns the new value.
+func (i *Int32) Add(n int32) int32 {
+	return atomic.AddInt32(&i.v, n)
+}
+
+// Sub atomically subtracts from the wrapped int32 and returns the new value.
+func (i *Int32) Sub(n int32) int32 {
+	return atomic.AddInt32(&i.v, -n)
+}
+
+// Inc atomically increments the wrapped int32 and returns the new value.
+func (i *Int32) Inc() int32 {
+	return i.Add(1)
+}
+
+// Dec atomically decrements the wrapped int32 and returns the new value.
+func (i *Int32) Dec() int32 {
+	return i.Sub(1)
+}
+
+// CAS is an atomic compare-and-swap.
+func (i *Int32) CAS(old, new int32) bool {
+	return atomic.CompareAndSwapInt32(&i.v, old, new)
+}
+
+// Store atomically stores the passed value.
+func (i *Int32) Store(n int32) {
+	atomic.StoreInt32(&i.v, n)
+}
+
+// Swap atomically swaps the wrapped int32 and returns the old value.
+func (i *Int32) Swap(n int32) int32 {
+	return atomic.SwapInt32(&i.v, n)
+}
+
+// Int64 is an atomic wrapper around an int64.
+type Int64 struct{ v int64 }
+
+// NewInt64 creates an Int64.
+func NewInt64(i int64) *Int64 {
+	return &Int64{i}
+}
+
+// Load atomically loads the wrapped value.
+func (i *Int64) Load() int64 {
+	return atomic.LoadInt64(&i.v)
+}
+
+// Add atomically adds to the wrapped int64 and returns the new value.
+func (i *Int64) Add(n int64) int64 {
+	return atomic.AddInt64(&i.v, n)
+}
+
+// Sub atomically subtracts from the wrapped int64 and returns the new value.
+func (i *Int64) Sub(n int64) int64 {
+	return atomic.AddInt64(&i.v, -n)
+}
+
+// Inc atomically increments the wrapped int64 and returns the new value.
+func (i *Int64) Inc() int64 {
+	return i.Add(1)
+}
+
+// Dec atomically decrements the wrapped int64 and returns the new value.
+func (i *Int64) Dec() int64 {
+	return i.Sub(1)
+}
+
+// CAS is an atomic compare-and-swap.
+func (i *Int64) CAS(old, new int64) bool {
+	return atomic.CompareAndSwapInt64(&i.v, old, new)
+}
+
+// Store atomically stores the passed value.
+func (i *Int64) Store(n int64) {
+	atomic.StoreInt64(&i.v, n)
+}
+
+// Swap atomically swaps the wrapped int64 and returns the old value.
+func (i *Int64) Swap(n int64) int64 {
+	return atomic.SwapInt64(&i.v, n)
+}
+
+// Uint32 is an atomic wrapper around an uint32.
+type Uint32 struct{ v uint32 }
+
+// NewUint32 creates a Uint32.
+func NewUint32(i uint32) *Uint32 {
+	return &Uint32{i}
+}
+
+// Load atomically loads the wrapped value.
+func (i *Uint32) Load() uint32 {
+	return atomic.LoadUint32(&i.v)
+}
+
+// Add atomically adds to the wrapped uint32 and returns the new value.
+func (i *Uint32) Add(n uint32) uint32 {
+	return atomic.AddUint32(&i.v, n)
+}
+
+// Sub atomically subtracts from the wrapped uint32 and returns the new value.
+func (i *Uint32) Sub(n uint32) uint32 {
+	return atomic.AddUint32(&i.v, ^(n - 1))
+}
+
+// Inc atomically increments the wrapped uint32 and returns the new value.
+func (i *Uint32) Inc() uint32 {
+	return i.Add(1)
+}
+
+// Dec atomically decrements the wrapped int32 and returns the new value.
+func (i *Uint32) Dec() uint32 {
+	return i.Sub(1)
+}
+
+// CAS is an atomic compare-and-swap.
+func (i *Uint32) CAS(old, new uint32) bool {
+	return atomic.CompareAndSwapUint32(&i.v, old, new)
+}
+
+// Store atomically stores the passed value.
+func (i *Uint32) Store(n uint32) {
+	atomic.StoreUint32(&i.v, n)
+}
+
+// Swap atomically swaps the wrapped uint32 and returns the old value.
+func (i *Uint32) Swap(n uint32) uint32 {
+	return atomic.SwapUint32(&i.v, n)
+}
+
+// Uint64 is an atomic wrapper around a uint64.
+type Uint64 struct{ v uint64 }
+
+// NewUint64 creates a Uint64.
+func NewUint64(i uint64) *Uint64 {
+	return &Uint64{i}
+}
+
+// Load atomically loads the wrapped value.
+func (i *Uint64) Load() uint64 {
+	return atomic.LoadUint64(&i.v)
+}
+
+// Add atomically adds to the wrapped uint64 and returns the new value.
+func (i *Uint64) Add(n uint64) uint64 {
+	return atomic.AddUint64(&i.v, n)
+}
+
+// Sub atomically subtracts from the wrapped uint64 and returns the new value.
+func (i *Uint64) Sub(n uint64) uint64 {
+	return atomic.AddUint64(&i.v, ^(n - 1))
+}
+
+// Inc atomically increments the wrapped uint64 and returns the new value.
+func (i *Uint64) Inc() uint64 {
+	return i.Add(1)
+}
+
+// Dec atomically decrements the wrapped uint64 and returns the new value.
+func (i *Uint64) Dec() uint64 {
+	return i.Sub(1)
+}
+
+// CAS is an atomic compare-and-swap.
+func (i *Uint64) CAS(old, new uint64) bool {
+	return atomic.CompareAndSwapUint64(&i.v, old, new)
+}
+
+// Store atomically stores the passed value.
+func (i *Uint64) Store(n uint64) {
+	atomic.StoreUint64(&i.v, n)
+}
+
+// Swap atomically swaps the wrapped uint64 and returns the old value.
+func (i *Uint64) Swap(n uint64) uint64 {
+	return atomic.SwapUint64(&i.v, n)
+}
+
+// Bool is an atomic Boolean.
+type Bool struct{ v uint32 }
+
+// NewBool creates a Bool.
+func NewBool(initial bool) *Bool {
+	return &Bool{boolToInt(initial)}
+}
+
+// Load atomically loads the Boolean.
+func (b *Bool) Load() bool {
+	return truthy(atomic.LoadUint32(&b.v))
+}
+
+// CAS is an atomic compare-and-swap.
+func (b *Bool) CAS(old, new bool) bool {
+	return atomic.CompareAndSwapUint32(&b.v, boolToInt(old), boolToInt(new))
+}
+
+// Store atomically stores the passed value.
+func (b *Bool) Store(new bool) {
+	atomic.StoreUint32(&b.v, boolToInt(new))
+}
+
+// Swap sets the given value and returns the previous value.
+func (b *Bool) Swap(new bool) bool {
+	return truthy(atomic.SwapUint32(&b.v, boolToInt(new)))
+}
+
+// Toggle atomically negates the Boolean and returns the previous value.
+func (b *Bool) Toggle() bool {
+	return truthy(atomic.AddUint32(&b.v, 1) - 1)
+}
+
+func truthy(n uint32) bool {
+	return n&1 == 1
+}
+
+func boolToInt(b bool) uint32 {
+	if b {
+		return 1
+	}
+	return 0
+}
+
+// Float64 is an atomic wrapper around float64.
+type Float64 struct {
+	v uint64
+}
+
+// NewFloat64 creates a Float64.
+func NewFloat64(f float64) *Float64 {
+	return &Float64{math.Float64bits(f)}
+}
+
+// Load atomically loads the wrapped value.
+func (f *Float64) Load() float64 {
+	return math.Float64frombits(atomic.LoadUint64(&f.v))
+}
+
+// Store atomically stores the passed value.
+func (f *Float64) Store(s float64) {
+	atomic.StoreUint64(&f.v, math.Float64bits(s))
+}
+
+// Add atomically adds to the wrapped float64 and returns the new value.
+func (f *Float64) Add(s float64) float64 {
+	for {
+		old := f.Load()
+		new := old + s
+		if f.CAS(old, new) {
+			return new
+		}
+	}
+}
+
+// Sub atomically subtracts from the wrapped float64 and returns the new value.
+func (f *Float64) Sub(s float64) float64 {
+	return f.Add(-s)
+}
+
+// CAS is an atomic compare-and-swap.
+func (f *Float64) CAS(old, new float64) bool {
+	return atomic.CompareAndSwapUint64(&f.v, math.Float64bits(old), math.Float64bits(new))
+}
+
+// Duration is an atomic wrapper around time.Duration
+// https://godoc.org/time#Duration
+type Duration struct {
+	v Int64
+}
+
+// NewDuration creates a Duration.
+func NewDuration(d time.Duration) *Duration {
+	return &Duration{v: *NewInt64(int64(d))}
+}
+
+// Load atomically loads the wrapped value.
+func (d *Duration) Load() time.Duration {
+	return time.Duration(d.v.Load())
+}
+
+// Store atomically stores the passed value.
+func (d *Duration) Store(n time.Duration) {
+	d.v.Store(int64(n))
+}
+
+// Add atomically adds to the wrapped time.Duration and returns the new value.
+func (d *Duration) Add(n time.Duration) time.Duration {
+	return time.Duration(d.v.Add(int64(n)))
+}
+
+// Sub atomically subtracts from the wrapped time.Duration and returns the new value.
+func (d *Duration) Sub(n time.Duration) time.Duration {
+	return time.Duration(d.v.Sub(int64(n)))
+}
+
+// Swap atomically swaps the wrapped time.Duration and returns the old value.
+func (d *Duration) Swap(n time.Duration) time.Duration {
+	return time.Duration(d.v.Swap(int64(n)))
+}
+
+// CAS is an atomic compare-and-swap.
+func (d *Duration) CAS(old, new time.Duration) bool {
+	return d.v.CAS(int64(old), int64(new))
+}
+
+// Value shadows the type of the same name from sync/atomic
+// https://godoc.org/sync/atomic#Value
+type Value struct{ atomic.Value }
diff --git a/vendor/go.uber.org/atomic/error.go b/vendor/go.uber.org/atomic/error.go
new file mode 100644
index 000000000..0489d19ba
--- /dev/null
+++ b/vendor/go.uber.org/atomic/error.go
@@ -0,0 +1,55 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package atomic
+
+// Error is an atomic type-safe wrapper around Value for errors
+type Error struct{ v Value }
+
+// errorHolder is non-nil holder for error object.
+// atomic.Value panics on saving nil object, so err object needs to be
+// wrapped with valid object first.
+type errorHolder struct{ err error }
+
+// NewError creates new atomic error object
+func NewError(err error) *Error {
+	e := &Error{}
+	if err != nil {
+		e.Store(err)
+	}
+	return e
+}
+
+// Load atomically loads the wrapped error
+func (e *Error) Load() error {
+	v := e.v.Load()
+	if v == nil {
+		return nil
+	}
+
+	eh := v.(errorHolder)
+	return eh.err
+}
+
+// Store atomically stores error.
+// NOTE: a holder object is allocated on each Store call.
+func (e *Error) Store(err error) {
+	e.v.Store(errorHolder{err: err})
+}
diff --git a/vendor/go.uber.org/atomic/glide.lock b/vendor/go.uber.org/atomic/glide.lock
new file mode 100644
index 000000000..3c72c5997
--- /dev/null
+++ b/vendor/go.uber.org/atomic/glide.lock
@@ -0,0 +1,17 @@
+hash: f14d51408e3e0e4f73b34e4039484c78059cd7fc5f4996fdd73db20dc8d24f53
+updated: 2016-10-27T00:10:51.16960137-07:00
+imports: []
+testImports:
+- name: github.com/davecgh/go-spew
+  version: 5215b55f46b2b919f50a1df0eaa5886afe4e3b3d
+  subpackages:
+  - spew
+- name: github.com/pmezard/go-difflib
+  version: d8ed2627bdf02c080bf22230dbb337003b7aba2d
+  subpackages:
+  - difflib
+- name: github.com/stretchr/testify
+  version: d77da356e56a7428ad25149ca77381849a6a5232
+  subpackages:
+  - assert
+  - require
diff --git a/vendor/go.uber.org/atomic/glide.yaml b/vendor/go.uber.org/atomic/glide.yaml
new file mode 100644
index 000000000..4cf608ec0
--- /dev/null
+++ b/vendor/go.uber.org/atomic/glide.yaml
@@ -0,0 +1,6 @@
+package: go.uber.org/atomic
+testImport:
+- package: github.com/stretchr/testify
+  subpackages:
+  - assert
+  - require
diff --git a/vendor/go.uber.org/atomic/string.go b/vendor/go.uber.org/atomic/string.go
new file mode 100644
index 000000000..ede8136fa
--- /dev/null
+++ b/vendor/go.uber.org/atomic/string.go
@@ -0,0 +1,49 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package atomic
+
+// String is an atomic type-safe wrapper around Value for strings.
+type String struct{ v Value }
+
+// NewString creates a String.
+func NewString(str string) *String {
+	s := &String{}
+	if str != "" {
+		s.Store(str)
+	}
+	return s
+}
+
+// Load atomically loads the wrapped string.
+func (s *String) Load() string {
+	v := s.v.Load()
+	if v == nil {
+		return ""
+	}
+	return v.(string)
+}
+
+// Store atomically stores the passed string.
+// Note: Converting the string to an interface{} to store in the Value
+// requires an allocation.
+func (s *String) Store(str string) {
+	s.v.Store(str)
+}
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 53239b7cd..3fdb02fbc 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -442,7 +442,7 @@ github.com/stretchr/testify/require
 github.com/syndtr/gocapability/capability
 # github.com/tchap/go-patricia v2.3.0+incompatible
 github.com/tchap/go-patricia/patricia
-# github.com/uber/jaeger-client-go v2.19.0+incompatible
+# github.com/uber/jaeger-client-go v2.20.0+incompatible
 github.com/uber/jaeger-client-go
 github.com/uber/jaeger-client-go/config
 github.com/uber/jaeger-client-go/internal/baggage
@@ -491,6 +491,8 @@ github.com/xeipuuv/gojsonpointer
 github.com/xeipuuv/gojsonreference
 # github.com/xeipuuv/gojsonschema v1.1.0
 github.com/xeipuuv/gojsonschema
+# go.uber.org/atomic v1.4.0
+go.uber.org/atomic
 # golang.org/x/crypto v0.0.0-20190927123631-a832865fa7ad
 golang.org/x/crypto/ssh/terminal
 golang.org/x/crypto/openpgp