diff --git a/pkg/endpoints/handlers/proxy.go b/pkg/endpoints/handlers/proxy.go
index f8c1a60e9..c774e38bd 100644
--- a/pkg/endpoints/handlers/proxy.go
+++ b/pkg/endpoints/handlers/proxy.go
@@ -53,18 +53,22 @@ type ProxyHandler struct {
 }
 
 func (r *ProxyHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	reqStart := time.Now()
 	proxyHandlerTraceID := rand.Int63()
 
-	var verb string
-	var apiResource, subresource string
+	var verb, apiResource, subresource, scope string
 	var httpCode int
-	reqStart := time.Now()
+
 	defer func() {
+		responseLength := 0
+		if rw, ok := w.(*metrics.ResponseWriterDelegator); ok {
+			responseLength = rw.ContentLength()
+		}
 		metrics.Monitor(
-			verb, apiResource, subresource,
+			verb, apiResource, subresource, scope,
 			net.GetHTTPClient(req),
 			w.Header().Get("Content-Type"),
-			httpCode, reqStart,
+			httpCode, responseLength, reqStart,
 		)
 	}()
 
@@ -88,6 +92,10 @@ func (r *ProxyHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	}
 	verb = requestInfo.Verb
 	namespace, resource, subresource, parts := requestInfo.Namespace, requestInfo.Resource, requestInfo.Subresource, requestInfo.Parts
+	scope = "cluster"
+	if namespace != "" {
+		scope = "namespace"
+	}
 
 	ctx = request.WithNamespace(ctx, namespace)
 	if len(parts) < 2 {
diff --git a/pkg/endpoints/installer.go b/pkg/endpoints/installer.go
index d740336f0..b8f6a0386 100644
--- a/pkg/endpoints/installer.go
+++ b/pkg/endpoints/installer.go
@@ -567,6 +567,12 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 			namespaced = ""
 		}
 
+		// This variable is calculated for the purpose of instrumentation.
+		namespaceScope := "cluster"
+		if namespaced != "" {
+			namespaceScope = "namespace"
+		}
+
 		if kubeVerb, found := toDiscoveryKubeVerb[action.Verb]; found {
 			if len(kubeVerb) != 0 {
 				kubeVerbs[kubeVerb] = struct{}{}
@@ -593,7 +599,7 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 			} else {
 				handler = restfulGetResource(getter, exporter, reqScope)
 			}
-			handler = metrics.InstrumentRouteFunc(action.Verb, resource, subresource, handler)
+			handler = metrics.InstrumentRouteFunc(action.Verb, resource, subresource, namespaceScope, handler)
 			if a.enableAPIResponseCompression {
 				handler = genericfilters.RestfulWithCompression(handler, a.group.Context)
 			}
@@ -625,7 +631,7 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 			if hasSubresource {
 				doc = "list " + subresource + " of objects of kind " + kind
 			}
-			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, restfulListResource(lister, watcher, reqScope, false, a.minRequestTimeout))
+			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, namespaceScope, restfulListResource(lister, watcher, reqScope, false, a.minRequestTimeout))
 			if a.enableAPIResponseCompression {
 				handler = genericfilters.RestfulWithCompression(handler, a.group.Context)
 			}
@@ -660,7 +666,7 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 			if hasSubresource {
 				doc = "replace " + subresource + " of the specified " + kind
 			}
-			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, restfulUpdateResource(updater, reqScope, a.group.Typer, admit))
+			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, namespaceScope, restfulUpdateResource(updater, reqScope, a.group.Typer, admit))
 			route := ws.PUT(action.Path).To(handler).
 				Doc(doc).
 				Param(ws.QueryParameter("pretty", "If 'true', then the output is pretty printed.")).
@@ -676,7 +682,7 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 			if hasSubresource {
 				doc = "partially update " + subresource + " of the specified " + kind
 			}
-			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, restfulPatchResource(patcher, reqScope, admit, mapping.ObjectConvertor))
+			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, namespaceScope, restfulPatchResource(patcher, reqScope, admit, mapping.ObjectConvertor))
 			route := ws.PATCH(action.Path).To(handler).
 				Doc(doc).
 				Param(ws.QueryParameter("pretty", "If 'true', then the output is pretty printed.")).
@@ -695,7 +701,7 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 			} else {
 				handler = restfulCreateResource(creater, reqScope, a.group.Typer, admit)
 			}
-			handler = metrics.InstrumentRouteFunc(action.Verb, resource, subresource, handler)
+			handler = metrics.InstrumentRouteFunc(action.Verb, resource, subresource, namespaceScope, handler)
 			article := getArticleForNoun(kind, " ")
 			doc := "create" + article + kind
 			if hasSubresource {
@@ -717,7 +723,7 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 			if hasSubresource {
 				doc = "delete " + subresource + " of" + article + kind
 			}
-			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, restfulDeleteResource(gracefulDeleter, isGracefulDeleter, reqScope, admit))
+			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, namespaceScope, restfulDeleteResource(gracefulDeleter, isGracefulDeleter, reqScope, admit))
 			route := ws.DELETE(action.Path).To(handler).
 				Doc(doc).
 				Param(ws.QueryParameter("pretty", "If 'true', then the output is pretty printed.")).
@@ -738,7 +744,7 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 			if hasSubresource {
 				doc = "delete collection of " + subresource + " of a " + kind
 			}
-			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, restfulDeleteCollection(collectionDeleter, isCollectionDeleter, reqScope, admit))
+			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, namespaceScope, restfulDeleteCollection(collectionDeleter, isCollectionDeleter, reqScope, admit))
 			route := ws.DELETE(action.Path).To(handler).
 				Doc(doc).
 				Param(ws.QueryParameter("pretty", "If 'true', then the output is pretty printed.")).
@@ -757,7 +763,7 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 			if hasSubresource {
 				doc = "watch changes to " + subresource + " of an object of kind " + kind
 			}
-			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, restfulListResource(lister, watcher, reqScope, true, a.minRequestTimeout))
+			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, namespaceScope, restfulListResource(lister, watcher, reqScope, true, a.minRequestTimeout))
 			route := ws.GET(action.Path).To(handler).
 				Doc(doc).
 				Param(ws.QueryParameter("pretty", "If 'true', then the output is pretty printed.")).
@@ -776,7 +782,7 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 			if hasSubresource {
 				doc = "watch individual changes to a list of " + subresource + " of " + kind
 			}
-			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, restfulListResource(lister, watcher, reqScope, true, a.minRequestTimeout))
+			handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, namespaceScope, restfulListResource(lister, watcher, reqScope, true, a.minRequestTimeout))
 			route := ws.GET(action.Path).To(handler).
 				Doc(doc).
 				Param(ws.QueryParameter("pretty", "If 'true', then the output is pretty printed.")).
@@ -794,20 +800,20 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 		// TODO: DEPRECATED in v1.2.
 		case "PROXY": // Proxy requests to a resource.
 			// Accept all methods as per http://issue.k8s.io/3996
-			routes = append(routes, buildProxyRoute(ws, "GET", a.prefix, action.Path, proxyHandler, namespaced, kind, resource, subresource, hasSubresource, action.Params, operationSuffix))
-			routes = append(routes, buildProxyRoute(ws, "PUT", a.prefix, action.Path, proxyHandler, namespaced, kind, resource, subresource, hasSubresource, action.Params, operationSuffix))
-			routes = append(routes, buildProxyRoute(ws, "POST", a.prefix, action.Path, proxyHandler, namespaced, kind, resource, subresource, hasSubresource, action.Params, operationSuffix))
-			routes = append(routes, buildProxyRoute(ws, "PATCH", a.prefix, action.Path, proxyHandler, namespaced, kind, resource, subresource, hasSubresource, action.Params, operationSuffix))
-			routes = append(routes, buildProxyRoute(ws, "DELETE", a.prefix, action.Path, proxyHandler, namespaced, kind, resource, subresource, hasSubresource, action.Params, operationSuffix))
-			routes = append(routes, buildProxyRoute(ws, "HEAD", a.prefix, action.Path, proxyHandler, namespaced, kind, resource, subresource, hasSubresource, action.Params, operationSuffix))
-			routes = append(routes, buildProxyRoute(ws, "OPTIONS", a.prefix, action.Path, proxyHandler, namespaced, kind, resource, subresource, hasSubresource, action.Params, operationSuffix))
+			routes = append(routes, buildProxyRoute(ws, "GET", a.prefix, action.Path, kind, resource, subresource, namespaced, namespaceScope, hasSubresource, action.Params, proxyHandler, operationSuffix))
+			routes = append(routes, buildProxyRoute(ws, "PUT", a.prefix, action.Path, kind, resource, subresource, namespaced, namespaceScope, hasSubresource, action.Params, proxyHandler, operationSuffix))
+			routes = append(routes, buildProxyRoute(ws, "POST", a.prefix, action.Path, kind, resource, subresource, namespaced, namespaceScope, hasSubresource, action.Params, proxyHandler, operationSuffix))
+			routes = append(routes, buildProxyRoute(ws, "PATCH", a.prefix, action.Path, kind, resource, subresource, namespaced, namespaceScope, hasSubresource, action.Params, proxyHandler, operationSuffix))
+			routes = append(routes, buildProxyRoute(ws, "DELETE", a.prefix, action.Path, kind, resource, subresource, namespaced, namespaceScope, hasSubresource, action.Params, proxyHandler, operationSuffix))
+			routes = append(routes, buildProxyRoute(ws, "HEAD", a.prefix, action.Path, kind, resource, subresource, namespaced, namespaceScope, hasSubresource, action.Params, proxyHandler, operationSuffix))
+			routes = append(routes, buildProxyRoute(ws, "OPTIONS", a.prefix, action.Path, kind, resource, subresource, namespaced, namespaceScope, hasSubresource, action.Params, proxyHandler, operationSuffix))
 		case "CONNECT":
 			for _, method := range connecter.ConnectMethods() {
 				doc := "connect " + method + " requests to " + kind
 				if hasSubresource {
 					doc = "connect " + method + " requests to " + subresource + " of " + kind
 				}
-				handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, restfulConnectResource(connecter, reqScope, admit, path, hasSubresource))
+				handler := metrics.InstrumentRouteFunc(action.Verb, resource, subresource, namespaceScope, restfulConnectResource(connecter, reqScope, admit, path, hasSubresource))
 				route := ws.Method(method).Path(action.Path).
 					To(handler).
 					Doc(doc).
@@ -868,12 +874,17 @@ func routeFunction(handler http.Handler) restful.RouteFunction {
 	}
 }
 
-func buildProxyRoute(ws *restful.WebService, method string, prefix string, path string, proxyHandler http.Handler, namespaced, kind, resource, subresource string, hasSubresource bool, params []*restful.Parameter, operationSuffix string) *restful.RouteBuilder {
+func buildProxyRoute(ws *restful.WebService,
+	method, prefix, path, kind, resource, subresource, namespaced, namespaceScope string,
+	hasSubresource bool,
+	params []*restful.Parameter,
+	proxyHandler http.Handler,
+	operationSuffix string) *restful.RouteBuilder {
 	doc := "proxy " + method + " requests to " + kind
 	if hasSubresource {
 		doc = "proxy " + method + " requests to " + subresource + " of " + kind
 	}
-	handler := metrics.InstrumentRouteFunc("PROXY", resource, subresource, routeFunction(proxyHandler))
+	handler := metrics.InstrumentRouteFunc("PROXY", resource, subresource, namespaceScope, routeFunction(proxyHandler))
 	proxyRoute := ws.Method(method).Path(path).To(handler).
 		Doc(doc).
 		Operation("proxy" + strings.Title(method) + namespaced + kind + strings.Title(subresource) + operationSuffix).
diff --git a/pkg/endpoints/metrics/metrics.go b/pkg/endpoints/metrics/metrics.go
index d26d94d24..a6bf6a862 100644
--- a/pkg/endpoints/metrics/metrics.go
+++ b/pkg/endpoints/metrics/metrics.go
@@ -18,6 +18,7 @@ package metrics
 
 import (
 	"bufio"
+	//"fmt"
 	"net"
 	"net/http"
 	"regexp"
@@ -26,6 +27,7 @@ import (
 	"time"
 
 	utilnet "k8s.io/apimachinery/pkg/util/net"
+	//utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 
 	"github.com/emicklei/go-restful"
 	"github.com/prometheus/client_golang/prometheus"
@@ -44,7 +46,7 @@ var (
 	requestLatencies = prometheus.NewHistogramVec(
 		prometheus.HistogramOpts{
 			Name: "apiserver_request_latencies",
-			Help: "Response latency distribution in microseconds for each verb, resource and client.",
+			Help: "Response latency distribution in microseconds for each verb, resource and subresource.",
 			// Use buckets ranging from 125 ms to 8 seconds.
 			Buckets: prometheus.ExponentialBuckets(125000, 2.0, 7),
 		},
@@ -53,12 +55,21 @@ var (
 	requestLatenciesSummary = prometheus.NewSummaryVec(
 		prometheus.SummaryOpts{
 			Name: "apiserver_request_latencies_summary",
-			Help: "Response latency summary in microseconds for each verb and resource.",
+			Help: "Response latency summary in microseconds for each verb, resource and subresource.",
 			// Make the sliding window of 1h.
 			MaxAge: time.Hour,
 		},
 		[]string{"verb", "resource", "subresource"},
 	)
+	responseSizes = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name: "apiserver_response_sizes",
+			Help: "Response size distribution in bytes for each verb, resource, subresource and scope (namespace/cluster).",
+			// Use buckets ranging from 1000 bytes (1KB) to 10^9 bytes (1GB).
+			Buckets: prometheus.ExponentialBuckets(1000, 10.0, 7),
+		},
+		[]string{"verb", "resource", "subresource", "scope"},
+	)
 	kubectlExeRegexp = regexp.MustCompile(`^.*((?i:kubectl\.exe))`)
 )
 
@@ -67,20 +78,25 @@ func Register() {
 	prometheus.MustRegister(requestCounter)
 	prometheus.MustRegister(requestLatencies)
 	prometheus.MustRegister(requestLatenciesSummary)
+	prometheus.MustRegister(responseSizes)
 }
 
 // Monitor records a request to the apiserver endpoints that follow the Kubernetes API conventions.  verb must be
 // uppercase to be backwards compatible with existing monitoring tooling.
-func Monitor(verb, resource, subresource, client, contentType string, httpCode int, reqStart time.Time) {
+func Monitor(verb, resource, subresource, scope, client, contentType string, httpCode, respSize int, reqStart time.Time) {
 	elapsed := float64((time.Since(reqStart)) / time.Microsecond)
 	requestCounter.WithLabelValues(verb, resource, subresource, client, contentType, codeToString(httpCode)).Inc()
 	requestLatencies.WithLabelValues(verb, resource, subresource).Observe(elapsed)
 	requestLatenciesSummary.WithLabelValues(verb, resource, subresource).Observe(elapsed)
+	// We are only interested in response sizes of read requests.
+	if verb == "GET" || verb == "LIST" {
+		responseSizes.WithLabelValues(verb, resource, subresource, scope).Observe(float64(respSize))
+	}
 }
 
 // MonitorRequest handles standard transformations for client and the reported verb and then invokes Monitor to record
 // a request. verb must be uppercase to be backwards compatible with existing monitoring tooling.
-func MonitorRequest(request *http.Request, verb, resource, subresource, contentType string, httpCode int, reqStart time.Time) {
+func MonitorRequest(request *http.Request, verb, resource, subresource, scope, contentType string, httpCode, respSize int, reqStart time.Time) {
 	reportedVerb := verb
 	if verb == "LIST" {
 		// see apimachinery/pkg/runtime/conversion.go Convert_Slice_string_To_bool
@@ -90,23 +106,25 @@ func MonitorRequest(request *http.Request, verb, resource, subresource, contentT
 			}
 		}
 	}
+
 	client := cleanUserAgent(utilnet.GetHTTPClient(request))
-	Monitor(reportedVerb, resource, subresource, client, contentType, httpCode, reqStart)
+	Monitor(reportedVerb, resource, subresource, scope, client, contentType, httpCode, respSize, reqStart)
 }
 
 func Reset() {
 	requestCounter.Reset()
 	requestLatencies.Reset()
 	requestLatenciesSummary.Reset()
+	responseSizes.Reset()
 }
 
 // InstrumentRouteFunc works like Prometheus' InstrumentHandlerFunc but wraps
 // the go-restful RouteFunction instead of a HandlerFunc
-func InstrumentRouteFunc(verb, resource, subresource string, routeFunc restful.RouteFunction) restful.RouteFunction {
+func InstrumentRouteFunc(verb, resource, subresource, scope string, routeFunc restful.RouteFunction) restful.RouteFunction {
 	return restful.RouteFunction(func(request *restful.Request, response *restful.Response) {
 		now := time.Now()
 
-		delegate := &responseWriterDelegator{ResponseWriter: response.ResponseWriter}
+		delegate := &ResponseWriterDelegator{ResponseWriter: response.ResponseWriter}
 
 		_, cn := response.ResponseWriter.(http.CloseNotifier)
 		_, fl := response.ResponseWriter.(http.Flusher)
@@ -121,7 +139,7 @@ func InstrumentRouteFunc(verb, resource, subresource string, routeFunc restful.R
 
 		routeFunc(request, response)
 
-		MonitorRequest(request.Request, verb, resource, subresource, rw.Header().Get("Content-Type"), delegate.status, now)
+		MonitorRequest(request.Request, verb, resource, subresource, scope, delegate.Header().Get("Content-Type"), delegate.Status(), delegate.ContentLength(), now)
 	})
 }
 
@@ -135,7 +153,8 @@ func cleanUserAgent(ua string) string {
 	return ua
 }
 
-type responseWriterDelegator struct {
+// ResponseWriterDelegator interface wraps http.ResponseWriter to additionally record content-length, status-code, etc.
+type ResponseWriterDelegator struct {
 	http.ResponseWriter
 
 	status      int
@@ -143,13 +162,13 @@ type responseWriterDelegator struct {
 	wroteHeader bool
 }
 
-func (r *responseWriterDelegator) WriteHeader(code int) {
+func (r *ResponseWriterDelegator) WriteHeader(code int) {
 	r.status = code
 	r.wroteHeader = true
 	r.ResponseWriter.WriteHeader(code)
 }
 
-func (r *responseWriterDelegator) Write(b []byte) (int, error) {
+func (r *ResponseWriterDelegator) Write(b []byte) (int, error) {
 	if !r.wroteHeader {
 		r.WriteHeader(http.StatusOK)
 	}
@@ -158,8 +177,16 @@ func (r *responseWriterDelegator) Write(b []byte) (int, error) {
 	return n, err
 }
 
+func (r *ResponseWriterDelegator) Status() int {
+	return r.status
+}
+
+func (r *ResponseWriterDelegator) ContentLength() int {
+	return int(r.written)
+}
+
 type fancyResponseWriterDelegator struct {
-	*responseWriterDelegator
+	*ResponseWriterDelegator
 }
 
 func (f *fancyResponseWriterDelegator) CloseNotify() <-chan bool {
diff --git a/pkg/server/filters/maxinflight.go b/pkg/server/filters/maxinflight.go
index 960d400d7..3e159c21f 100644
--- a/pkg/server/filters/maxinflight.go
+++ b/pkg/server/filters/maxinflight.go
@@ -109,7 +109,11 @@ func WithMaxInFlightLimit(
 						}
 					}
 				}
-				metrics.MonitorRequest(r, strings.ToUpper(requestInfo.Verb), requestInfo.Resource, requestInfo.Subresource, "", errors.StatusTooManyRequests, time.Now())
+				scope := "cluster"
+				if requestInfo.Namespace != "" {
+					scope = "namespace"
+				}
+				metrics.MonitorRequest(r, strings.ToUpper(requestInfo.Verb), requestInfo.Resource, requestInfo.Subresource, "", scope, errors.StatusTooManyRequests, 0, time.Now())
 				tooManyRequests(r, w)
 			}
 		}
diff --git a/pkg/server/filters/timeout.go b/pkg/server/filters/timeout.go
index 341670bc9..e3e21a5f0 100644
--- a/pkg/server/filters/timeout.go
+++ b/pkg/server/filters/timeout.go
@@ -60,7 +60,11 @@ func WithTimeoutForNonLongRunningRequests(handler http.Handler, requestContextMa
 		}
 		now := time.Now()
 		metricFn := func() {
-			metrics.MonitorRequest(req, strings.ToUpper(requestInfo.Verb), requestInfo.Resource, requestInfo.Subresource, "", http.StatusInternalServerError, now)
+			scope := "cluster"
+			if requestInfo.Namespace != "" {
+				scope = "namespace"
+			}
+			metrics.MonitorRequest(req, strings.ToUpper(requestInfo.Verb), requestInfo.Resource, requestInfo.Subresource, "", scope, http.StatusInternalServerError, 0, now)
 		}
 		return time.After(globalTimeout), metricFn, apierrors.NewServerTimeout(schema.GroupResource{Group: requestInfo.APIGroup, Resource: requestInfo.Resource}, requestInfo.Verb, 0)
 	}