diff --git a/vendor.mod b/vendor.mod
index 6a4daac071..ab595481c6 100644
--- a/vendor.mod
+++ b/vendor.mod
@@ -91,7 +91,7 @@ require (
 require (
 	github.com/agext/levenshtein v1.2.3 // indirect
 	github.com/armon/circbuf v0.0.0-20190214190532-5111143e8da2 // indirect
-	github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da // indirect
+	github.com/armon/go-metrics v0.4.1 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/cilium/ebpf v0.7.0 // indirect
diff --git a/vendor.sum b/vendor.sum
index 2167d99a1d..b58a7c2797 100644
--- a/vendor.sum
+++ b/vendor.sum
@@ -70,6 +70,7 @@ github.com/Azure/go-autorest/logger v0.2.1/go.mod h1:T9E3cAhj2VqvPOtCYAvby9aBXkZ
 github.com/Azure/go-autorest/tracing v0.6.0/go.mod h1:+vhtPC754Xsa23ID7GlGsrdKBpUA79WCAKPPZVC2DeU=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
+github.com/DataDog/datadog-go v3.2.0+incompatible/go.mod h1:LButxg5PwREeZtORoXG3tL4fMGNddJ+vMq1mwgfaqoQ=
 github.com/Graylog2/go-gelf v0.0.0-20191017102106-1550ee647df0 h1:cOjLyhBhe91glgZZNbQUg9BJC57l6BiSKov0Ivv7k0U=
 github.com/Graylog2/go-gelf v0.0.0-20191017102106-1550ee647df0/go.mod h1:fBaQWrftOD5CrVCUfoYGHs4X4VViTuGOXA8WloCjTY0=
 github.com/Microsoft/go-winio v0.4.11/go.mod h1:VhR8bwka0BXejwEJY73c50VrPtXAaKcyvVC4A4RozmA=
@@ -126,8 +127,9 @@ github.com/armon/circbuf v0.0.0-20150827004946-bbbad097214e/go.mod h1:3U/XgcO3hC
 github.com/armon/circbuf v0.0.0-20190214190532-5111143e8da2 h1:7Ip0wMmLHLRJdrloDxZfhMm0xrLXZS8+COSu2bXmEQs=
 github.com/armon/circbuf v0.0.0-20190214190532-5111143e8da2/go.mod h1:3U/XgcO3hCbHZ8TKRvWD2dDTCfh9M9ya+I9JpbB7O8o=
 github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
-github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da h1:8GUt8eRujhVEGZFFEjBj46YV4rDjvGrNxb0KMWYkL2I=
 github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da/go.mod h1:Q73ZrmVTwzkszR9V5SSuryQ31EELlFMUz1kKyl939pY=
+github.com/armon/go-metrics v0.4.1 h1:hR91U9KYmb6bLBYLQjyM+3j+rcd/UhE+G78SFnF8gJA=
+github.com/armon/go-metrics v0.4.1/go.mod h1:E6amYzXo6aW1tqzoZGT755KkbgrJsSdpwZ+3JqfkOG4=
 github.com/armon/go-radix v0.0.0-20150105235045-e39d623f12e8 h1:XGHqlQXxwVly7mpcroyCGuEaGv/yvtS6r4PSHryDgxU=
 github.com/armon/go-radix v0.0.0-20150105235045-e39d623f12e8/go.mod h1:ufUuZ+zHj4x4TnLV4JWEpy2hxWSpsRywHrMgIH9cCH8=
 github.com/asaskevich/govalidator v0.0.0-20190424111038-f61b66f89f4a/go.mod h1:lB+ZfQJz7igIIfQNfa7Ml4HSf2uFQQRzpGGRXenZAgY=
@@ -179,6 +181,8 @@ github.com/cilium/ebpf v0.4.0/go.mod h1:4tRaxcgiL706VnOzHOdBlY8IEAIdxINsQBcU4xJJ
 github.com/cilium/ebpf v0.6.2/go.mod h1:4tRaxcgiL706VnOzHOdBlY8IEAIdxINsQBcU4xJJXRs=
 github.com/cilium/ebpf v0.7.0 h1:1k/q3ATgxSXRdrmPfH8d7YK0GfqVsEKZAX9dQZvs56k=
 github.com/cilium/ebpf v0.7.0/go.mod h1:/oI2+1shJiTGAMgl6/RgJr36Eo1jzrRcAWbcXO2usCA=
+github.com/circonus-labs/circonus-gometrics v2.3.1+incompatible/go.mod h1:nmEj6Dob7S7YxXgwXpfOuvO54S+tGdZdw9fuRZt25Ag=
+github.com/circonus-labs/circonusllhist v0.1.3/go.mod h1:kMXHVDlOchFAehlya5ePtbp5jckzBHf4XRpQvBOLI+I=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cloudflare/cfssl v0.0.0-20180323000720-5d63dbd981b5 h1:PqZ3bA4yzwywivzk7PBQWngJp2/PAS0bWRZerKteicY=
 github.com/cloudflare/cfssl v0.0.0-20180323000720-5d63dbd981b5/go.mod h1:yMWuSON2oQp+43nFtAV/uvKQIFpSPerB57DCt9t8sSA=
@@ -608,6 +612,7 @@ github.com/hashicorp/errwrap v0.0.0-20141028054710-7554cd9344ce/go.mod h1:YH+1FK
 github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
 github.com/hashicorp/errwrap v1.1.0 h1:OxrOeh75EUXMY8TBjag2fzXGZ40LB6IKw45YeGUDY2I=
 github.com/hashicorp/errwrap v1.1.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
+github.com/hashicorp/go-cleanhttp v0.5.0/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
 github.com/hashicorp/go-cleanhttp v0.5.1/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
 github.com/hashicorp/go-hclog v0.9.2/go.mod h1:5CU+agLiy3J7N7QjHK5d05KxGsuXiQLrjA0H7acj2lQ=
 github.com/hashicorp/go-immutable-radix v1.0.0/go.mod h1:0y9vanUI8NX6FsYoO3zeMjhV/C5i9g4Q3DwcSNZ4P60=
@@ -623,6 +628,7 @@ github.com/hashicorp/go-multierror v0.0.0-20161216184304-ed905158d874/go.mod h1:
 github.com/hashicorp/go-multierror v1.0.0/go.mod h1:dHtQlpGsu+cZNNAkkCN/P3hoUDHhCYQXV3UM06sGGrk=
 github.com/hashicorp/go-multierror v1.1.1 h1:H5DkEtf6CXdFp0N0Em5UCwQpXMWke8IA0+lD48awMYo=
 github.com/hashicorp/go-multierror v1.1.1/go.mod h1:iw975J/qwKPdAO1clOe2L8331t/9/fmwbPZ6JB6eMoM=
+github.com/hashicorp/go-retryablehttp v0.5.3/go.mod h1:9B5zBasrRhHXnJnui7y6sL7es7NDiJgTc6Er0maI1Xs=
 github.com/hashicorp/go-retryablehttp v0.7.0/go.mod h1:vAew36LZh98gCBJNLH42IQ1ER/9wtLZZ8meHqQvEYWY=
 github.com/hashicorp/go-rootcerts v1.0.0/go.mod h1:K6zTfqpRlCUIjkwsN4Z+hiSfzSTQa6eBIzfwKfwNnHU=
 github.com/hashicorp/go-sockaddr v1.0.0/go.mod h1:7Xibr9yA9JjQq1JpNB2Vw7kxv8xerXegt+ozgdvDeDU=
@@ -679,6 +685,7 @@ github.com/jsimonetti/rtnetlink v0.0.0-20201009170750-9c6f07d100c1/go.mod h1:hqo
 github.com/jsimonetti/rtnetlink v0.0.0-20201110080708-d2c240429e6c/go.mod h1:huN4d1phzjhlOsNIjFsw2SVRbwIHj3fJDMEU2SDPTmg=
 github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
 github.com/json-iterator/go v1.1.7/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
+github.com/json-iterator/go v1.1.9/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
 github.com/json-iterator/go v1.1.10/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
 github.com/json-iterator/go v1.1.11/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
@@ -866,8 +873,9 @@ github.com/opencontainers/selinux v1.10.0/go.mod h1:2i0OySw99QjzBBQByd1Gr9gSjvuh
 github.com/opencontainers/selinux v1.10.1 h1:09LIPVRP3uuZGQvgR+SgMSNBd1Eb3vlRbGqQpoHsF8w=
 github.com/opencontainers/selinux v1.10.1/go.mod h1:2i0OySw99QjzBBQByd1Gr9gSjvuho1lHsJxIJ3gGbJI=
 github.com/opentracing/opentracing-go v1.1.0/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
-github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c h1:Lgl0gzECD8GnQ5QCWA8o6BtfL6mDH5rQgM4/fX3avOs=
 github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
+github.com/pascaldekloe/goe v0.1.0 h1:cBOtyMzM9HTpWjXfbbunk26uA6nG3a8n06Wieeh0MwY=
+github.com/pascaldekloe/goe v0.1.0/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
 github.com/pelletier/go-toml v1.8.1/go.mod h1:T2/BmBdy8dvIRq1a/8aqjN41wvWlN4lrapLU/GW4pbc=
 github.com/pelletier/go-toml v1.9.3/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c=
@@ -892,6 +900,7 @@ github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXP
 github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDft0ttaMvbicHlPoso=
 github.com/prometheus/client_golang v1.0.0/go.mod h1:db9x61etRT2tGnBNRi70OPL5FsnadC4Ky3P0J6CfImo=
 github.com/prometheus/client_golang v1.1.0/go.mod h1:I1FGZT9+L76gKKOs5djB6ezCbFQP1xR9D75/vuwEF3g=
+github.com/prometheus/client_golang v1.4.0/go.mod h1:e9GMxYsXl05ICDXkRhurwBS4Q3OK1iX/F2sw+iXX5zU=
 github.com/prometheus/client_golang v1.7.1/go.mod h1:PY5Wy2awLA44sXw4AOSfFBetzPP4j5+D6mVACh+pe2M=
 github.com/prometheus/client_golang v1.11.0/go.mod h1:Z6t4BnS23TR94PD6BsDNk8yVqroYurpAkEiz0P2BEV0=
 github.com/prometheus/client_golang v1.12.1 h1:ZiaPsmm9uiBeaSMRznKsCDNtPCS0T3JVDGF+06gjBzk=
@@ -907,6 +916,7 @@ github.com/prometheus/common v0.0.0-20181113130724-41aa239b4cce/go.mod h1:daVV7q
 github.com/prometheus/common v0.4.0/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
 github.com/prometheus/common v0.4.1/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
 github.com/prometheus/common v0.6.0/go.mod h1:eBmuwkDJBwy6iBfxCBob6t6dR6ENT/y+J+Zk0j9GMYc=
+github.com/prometheus/common v0.9.1/go.mod h1:yhUN8i9wzaXS3w1O07YhxHEBxD+W35wd8bs7vj7HSQ4=
 github.com/prometheus/common v0.10.0/go.mod h1:Tlit/dnDKsSWFlCLTWaA1cyBgKHSMdTB80sz/V91rCo=
 github.com/prometheus/common v0.26.0/go.mod h1:M7rCNAaPfAosfx8veZJCuw84e35h3Cfd9VFqTh1DIvc=
 github.com/prometheus/common v0.30.0/go.mod h1:vu+V0TpY+O6vW9J44gczi3Ap/oXXR10b+M/gUGO4Hls=
@@ -1014,6 +1024,7 @@ github.com/tonistiigi/go-archvariant v1.0.0 h1:5LC1eDWiBNflnTF1prCiX09yfNHIxDC/a
 github.com/tonistiigi/go-archvariant v1.0.0/go.mod h1:TxFmO5VS6vMq2kvs3ht04iPXtu2rUT/erOnGFYfk5Ho=
 github.com/tonistiigi/units v0.0.0-20180711220420-6950e57a87ea h1:SXhTLE6pb6eld/v/cCndK0AMpt1wiVFb/YYmqB3/QG0=
 github.com/tonistiigi/units v0.0.0-20180711220420-6950e57a87ea/go.mod h1:WPnis/6cRcDZSUvVmezrxJPkiO87ThFYsoUiMwWNDJk=
+github.com/tv42/httpunix v0.0.0-20150427012821-b75d8614f926/go.mod h1:9ESjWnEqriFuLhtthL60Sar/7RFoluCcXsuvEwTV5KM=
 github.com/tv42/httpunix v0.0.0-20191220191345-2ba4b9c3382c/go.mod h1:hzIxponao9Kjc7aWznkXaL4U4TWaDSs8zcsY4Ka08nM=
 github.com/u-root/uio v0.0.0-20210528114334-82958018845c/go.mod h1:LpEX5FO/cB+WF4TYGY1V5qktpaZLkKkSegbr0V4eYXA=
 github.com/ugorji/go v1.1.4/go.mod h1:uQMGLiO92mf5W77hV/PUCpI3pbzQx3CRekS0kk+RGrc=
diff --git a/vendor/github.com/armon/go-metrics/.gitignore b/vendor/github.com/armon/go-metrics/.gitignore
index 8c03ec112a..e5750f5720 100644
--- a/vendor/github.com/armon/go-metrics/.gitignore
+++ b/vendor/github.com/armon/go-metrics/.gitignore
@@ -22,3 +22,5 @@ _testmain.go
 *.exe
 
 /metrics.out
+
+.idea
diff --git a/vendor/github.com/armon/go-metrics/.travis.yml b/vendor/github.com/armon/go-metrics/.travis.yml
new file mode 100644
index 0000000000..87d230c8d7
--- /dev/null
+++ b/vendor/github.com/armon/go-metrics/.travis.yml
@@ -0,0 +1,13 @@
+language: go
+
+go:
+  - "1.x"
+
+env:
+  - GO111MODULE=on
+
+install:
+  - go get ./...
+
+script:
+  - go test ./...
diff --git a/vendor/github.com/armon/go-metrics/inmem.go b/vendor/github.com/armon/go-metrics/inmem.go
index 4e2d6a709e..7c427aca97 100644
--- a/vendor/github.com/armon/go-metrics/inmem.go
+++ b/vendor/github.com/armon/go-metrics/inmem.go
@@ -10,6 +10,8 @@ import (
 	"time"
 )
 
+var spaceReplacer = strings.NewReplacer(" ", "_")
+
 // InmemSink provides a MetricSink that does in-memory aggregation
 // without sending metrics over a network. It can be embedded within
 // an application to provide profiling information.
@@ -53,6 +55,10 @@ type IntervalMetrics struct {
 	// Samples maps the key to an AggregateSample,
 	// which has the rolled up view of a sample
 	Samples map[string]SampledValue
+
+	// done is closed when this interval has ended, and a new IntervalMetrics
+	// has been created to receive any future metrics.
+	done chan struct{}
 }
 
 // NewIntervalMetrics creates a new IntervalMetrics for a given interval
@@ -63,6 +69,7 @@ func NewIntervalMetrics(intv time.Time) *IntervalMetrics {
 		Points:   make(map[string][]float32),
 		Counters: make(map[string]SampledValue),
 		Samples:  make(map[string]SampledValue),
+		done:     make(chan struct{}),
 	}
 }
 
@@ -243,6 +250,8 @@ func (i *InmemSink) Data() []*IntervalMetrics {
 	copyCurrent := intervals[n-1]
 	current.RLock()
 	*copyCurrent = *current
+	// RWMutex is not safe to copy, so create a new instance on the copy
+	copyCurrent.RWMutex = sync.RWMutex{}
 
 	copyCurrent.Gauges = make(map[string]GaugeValue, len(current.Gauges))
 	for k, v := range current.Gauges {
@@ -255,44 +264,50 @@ func (i *InmemSink) Data() []*IntervalMetrics {
 	}
 	copyCurrent.Counters = make(map[string]SampledValue, len(current.Counters))
 	for k, v := range current.Counters {
-		copyCurrent.Counters[k] = v
+		copyCurrent.Counters[k] = v.deepCopy()
 	}
 	copyCurrent.Samples = make(map[string]SampledValue, len(current.Samples))
 	for k, v := range current.Samples {
-		copyCurrent.Samples[k] = v
+		copyCurrent.Samples[k] = v.deepCopy()
 	}
 	current.RUnlock()
 
 	return intervals
 }
 
-func (i *InmemSink) getExistingInterval(intv time.Time) *IntervalMetrics {
-	i.intervalLock.RLock()
-	defer i.intervalLock.RUnlock()
+// getInterval returns the current interval. A new interval is created if no
+// previous interval exists, or if the current time is beyond the window for the
+// current interval.
+func (i *InmemSink) getInterval() *IntervalMetrics {
+	intv := time.Now().Truncate(i.interval)
 
+	// Attempt to return the existing interval first, because it only requires
+	// a read lock.
+	i.intervalLock.RLock()
 	n := len(i.intervals)
 	if n > 0 && i.intervals[n-1].Interval == intv {
+		defer i.intervalLock.RUnlock()
 		return i.intervals[n-1]
 	}
-	return nil
-}
+	i.intervalLock.RUnlock()
 
-func (i *InmemSink) createInterval(intv time.Time) *IntervalMetrics {
 	i.intervalLock.Lock()
 	defer i.intervalLock.Unlock()
 
-	// Check for an existing interval
-	n := len(i.intervals)
+	// Re-check for an existing interval now that the lock is re-acquired.
+	n = len(i.intervals)
 	if n > 0 && i.intervals[n-1].Interval == intv {
 		return i.intervals[n-1]
 	}
 
-	// Add the current interval
 	current := NewIntervalMetrics(intv)
 	i.intervals = append(i.intervals, current)
-	n++
+	if n > 0 {
+		close(i.intervals[n-1].done)
+	}
 
-	// Truncate the intervals if they are too long
+	n++
+	// Prune old intervals if the count exceeds the max.
 	if n >= i.maxIntervals {
 		copy(i.intervals[0:], i.intervals[n-i.maxIntervals:])
 		i.intervals = i.intervals[:i.maxIntervals]
@@ -300,48 +315,24 @@ func (i *InmemSink) createInterval(intv time.Time) *IntervalMetrics {
 	return current
 }
 
-// getInterval returns the current interval to write to
-func (i *InmemSink) getInterval() *IntervalMetrics {
-	intv := time.Now().Truncate(i.interval)
-	if m := i.getExistingInterval(intv); m != nil {
-		return m
-	}
-	return i.createInterval(intv)
-}
-
 // Flattens the key for formatting, removes spaces
 func (i *InmemSink) flattenKey(parts []string) string {
 	buf := &bytes.Buffer{}
-	replacer := strings.NewReplacer(" ", "_")
 
-	if len(parts) > 0 {
-		replacer.WriteString(buf, parts[0])
-	}
-	for _, part := range parts[1:] {
-		replacer.WriteString(buf, ".")
-		replacer.WriteString(buf, part)
-	}
+	joined := strings.Join(parts, ".")
+
+	spaceReplacer.WriteString(buf, joined)
 
 	return buf.String()
 }
 
 // Flattens the key for formatting along with its labels, removes spaces
 func (i *InmemSink) flattenKeyLabels(parts []string, labels []Label) (string, string) {
-	buf := &bytes.Buffer{}
-	replacer := strings.NewReplacer(" ", "_")
-
-	if len(parts) > 0 {
-		replacer.WriteString(buf, parts[0])
-	}
-	for _, part := range parts[1:] {
-		replacer.WriteString(buf, ".")
-		replacer.WriteString(buf, part)
-	}
-
-	key := buf.String()
+	key := i.flattenKey(parts)
+	buf := bytes.NewBufferString(key)
 
 	for _, label := range labels {
-		replacer.WriteString(buf, fmt.Sprintf(";%s=%s", label.Name, label.Value))
+		spaceReplacer.WriteString(buf, fmt.Sprintf(";%s=%s", label.Name, label.Value))
 	}
 
 	return buf.String(), key
diff --git a/vendor/github.com/armon/go-metrics/inmem_endpoint.go b/vendor/github.com/armon/go-metrics/inmem_endpoint.go
index 504f1b3748..24eefa9638 100644
--- a/vendor/github.com/armon/go-metrics/inmem_endpoint.go
+++ b/vendor/github.com/armon/go-metrics/inmem_endpoint.go
@@ -1,6 +1,7 @@
 package metrics
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 	"sort"
@@ -41,6 +42,16 @@ type SampledValue struct {
 	DisplayLabels map[string]string `json:"Labels"`
 }
 
+// deepCopy allocates a new instance of AggregateSample
+func (source *SampledValue) deepCopy() SampledValue {
+	dest := *source
+	if source.AggregateSample != nil {
+		dest.AggregateSample = &AggregateSample{}
+		*dest.AggregateSample = *source.AggregateSample
+	}
+	return dest
+}
+
 // DisplayMetrics returns a summary of the metrics from the most recent finished interval.
 func (i *InmemSink) DisplayMetrics(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
 	data := i.Data()
@@ -52,12 +63,19 @@ func (i *InmemSink) DisplayMetrics(resp http.ResponseWriter, req *http.Request)
 		return nil, fmt.Errorf("no metric intervals have been initialized yet")
 	case n == 1:
 		// Show the current interval if it's all we have
-		interval = i.intervals[0]
+		interval = data[0]
 	default:
 		// Show the most recent finished interval if we have one
-		interval = i.intervals[n-2]
+		interval = data[n-2]
 	}
 
+	return newMetricSummaryFromInterval(interval), nil
+}
+
+func newMetricSummaryFromInterval(interval *IntervalMetrics) MetricsSummary {
+	interval.RLock()
+	defer interval.RUnlock()
+
 	summary := MetricsSummary{
 		Timestamp: interval.Interval.Round(time.Second).UTC().String(),
 		Gauges:    make([]GaugeValue, 0, len(interval.Gauges)),
@@ -90,7 +108,7 @@ func (i *InmemSink) DisplayMetrics(resp http.ResponseWriter, req *http.Request)
 	summary.Counters = formatSamples(interval.Counters)
 	summary.Samples = formatSamples(interval.Samples)
 
-	return summary, nil
+	return summary
 }
 
 func formatSamples(source map[string]SampledValue) []SampledValue {
@@ -116,3 +134,29 @@ func formatSamples(source map[string]SampledValue) []SampledValue {
 
 	return output
 }
+
+type Encoder interface {
+	Encode(interface{}) error
+}
+
+// Stream writes metrics using encoder.Encode each time an interval ends. Runs
+// until the request context is cancelled, or the encoder returns an error.
+// The caller is responsible for logging any errors from encoder.
+func (i *InmemSink) Stream(ctx context.Context, encoder Encoder) {
+	interval := i.getInterval()
+
+	for {
+		select {
+		case <-interval.done:
+			summary := newMetricSummaryFromInterval(interval)
+			if err := encoder.Encode(summary); err != nil {
+				return
+			}
+
+			// update interval to the next one
+			interval = i.getInterval()
+		case <-ctx.Done():
+			return
+		}
+	}
+}
diff --git a/vendor/github.com/armon/go-metrics/metrics.go b/vendor/github.com/armon/go-metrics/metrics.go
index cf9def748e..36642a4293 100644
--- a/vendor/github.com/armon/go-metrics/metrics.go
+++ b/vendor/github.com/armon/go-metrics/metrics.go
@@ -5,7 +5,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/hashicorp/go-immutable-radix"
+	iradix "github.com/hashicorp/go-immutable-radix"
 )
 
 type Label struct {
@@ -172,6 +172,12 @@ func (m *Metrics) UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabe
 	}
 }
 
+func (m *Metrics) Shutdown() {
+	if ss, ok := m.sink.(ShutdownSink); ok {
+		ss.Shutdown()
+	}
+}
+
 // labelIsAllowed return true if a should be included in metric
 // the caller should lock m.filterLock while calling this method
 func (m *Metrics) labelIsAllowed(label *Label) bool {
@@ -197,7 +203,7 @@ func (m *Metrics) filterLabels(labels []Label) []Label {
 	if labels == nil {
 		return nil
 	}
-	toReturn := labels[:0]
+	toReturn := []Label{}
 	for _, label := range labels {
 		if m.labelIsAllowed(&label) {
 			toReturn = append(toReturn, label)
@@ -228,12 +234,12 @@ func (m *Metrics) allowMetric(key []string, labels []Label) (bool, []Label) {
 func (m *Metrics) collectStats() {
 	for {
 		time.Sleep(m.ProfileInterval)
-		m.emitRuntimeStats()
+		m.EmitRuntimeStats()
 	}
 }
 
 // Emits various runtime statsitics
-func (m *Metrics) emitRuntimeStats() {
+func (m *Metrics) EmitRuntimeStats() {
 	// Export number of Goroutines
 	numRoutines := runtime.NumGoroutine()
 	m.SetGauge([]string{"runtime", "num_goroutines"}, float32(numRoutines))
@@ -269,10 +275,25 @@ func (m *Metrics) emitRuntimeStats() {
 	m.lastNumGC = num
 }
 
-// Inserts a string value at an index into the slice
+// Creates a new slice with the provided string value as the first element
+// and the provided slice values as the remaining values.
+// Ordering of the values in the provided input slice is kept in tact in the output slice.
 func insert(i int, v string, s []string) []string {
-	s = append(s, "")
-	copy(s[i+1:], s[i:])
-	s[i] = v
-	return s
+	// Allocate new slice to avoid modifying the input slice
+	newS := make([]string, len(s)+1)
+
+	// Copy s[0, i-1] into newS
+	for j := 0; j < i; j++ {
+		newS[j] = s[j]
+	}
+
+	// Insert provided element at index i
+	newS[i] = v
+
+	// Copy s[i, len(s)-1] into newS starting at newS[i+1]
+	for j := i; j < len(s); j++ {
+		newS[j+1] = s[j]
+	}
+
+	return newS
 }
diff --git a/vendor/github.com/armon/go-metrics/sink.go b/vendor/github.com/armon/go-metrics/sink.go
index 0b7d6e4be4..6f4108ff40 100644
--- a/vendor/github.com/armon/go-metrics/sink.go
+++ b/vendor/github.com/armon/go-metrics/sink.go
@@ -24,6 +24,15 @@ type MetricSink interface {
 	AddSampleWithLabels(key []string, val float32, labels []Label)
 }
 
+type ShutdownSink interface {
+	MetricSink
+
+	// Shutdown the metric sink, flush metrics to storage, and cleanup resources.
+	// Called immediately prior to application exit. Implementations must block
+	// until metrics are flushed to storage.
+	Shutdown()
+}
+
 // BlackholeSink is used to just blackhole messages
 type BlackholeSink struct{}
 
@@ -74,6 +83,14 @@ func (fh FanoutSink) AddSampleWithLabels(key []string, val float32, labels []Lab
 	}
 }
 
+func (fh FanoutSink) Shutdown() {
+	for _, s := range fh {
+		if ss, ok := s.(ShutdownSink); ok {
+			ss.Shutdown()
+		}
+	}
+}
+
 // sinkURLFactoryFunc is an generic interface around the *SinkFromURL() function provided
 // by each sink type
 type sinkURLFactoryFunc func(*url.URL) (MetricSink, error)
diff --git a/vendor/github.com/armon/go-metrics/start.go b/vendor/github.com/armon/go-metrics/start.go
index 32a28c4837..38976f8dc9 100644
--- a/vendor/github.com/armon/go-metrics/start.go
+++ b/vendor/github.com/armon/go-metrics/start.go
@@ -6,7 +6,7 @@ import (
 	"sync/atomic"
 	"time"
 
-	"github.com/hashicorp/go-immutable-radix"
+	iradix "github.com/hashicorp/go-immutable-radix"
 )
 
 // Config is used to configure metrics settings
@@ -48,6 +48,11 @@ func init() {
 	globalMetrics.Store(&Metrics{sink: &BlackholeSink{}})
 }
 
+// Default returns the shared global metrics instance.
+func Default() *Metrics {
+	return globalMetrics.Load().(*Metrics)
+}
+
 // DefaultConfig provides a sane default configuration
 func DefaultConfig(serviceName string) *Config {
 	c := &Config{
@@ -139,3 +144,15 @@ func UpdateFilter(allow, block []string) {
 func UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels []string) {
 	globalMetrics.Load().(*Metrics).UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels)
 }
+
+// Shutdown disables metric collection, then blocks while attempting to flush metrics to storage.
+// WARNING: Not all MetricSink backends support this functionality, and calling this will cause them to leak resources.
+// This is intended for use immediately prior to application exit.
+func Shutdown() {
+	m := globalMetrics.Load().(*Metrics)
+	// Swap whatever MetricSink is currently active with a BlackholeSink. Callers must not have a
+	// reason to expect that calls to the library will successfully collect metrics after Shutdown
+	// has been called.
+	globalMetrics.Store(&Metrics{sink: &BlackholeSink{}})
+	m.Shutdown()
+}
diff --git a/vendor/modules.txt b/vendor/modules.txt
index fe1e09e7c8..f0d638a892 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -62,8 +62,8 @@ github.com/agext/levenshtein
 # github.com/armon/circbuf v0.0.0-20190214190532-5111143e8da2
 ## explicit
 github.com/armon/circbuf
-# github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da
-## explicit
+# github.com/armon/go-metrics v0.4.1
+## explicit; go 1.12
 github.com/armon/go-metrics
 # github.com/armon/go-radix v0.0.0-20180808171621-7fddfc383310 => github.com/armon/go-radix v0.0.0-20150105235045-e39d623f12e8
 ## explicit