diff --git a/test/e2e/framework.go b/test/e2e/framework.go
index a68c9f23a4d..976496b7808 100644
--- a/test/e2e/framework.go
+++ b/test/e2e/framework.go
@@ -152,7 +152,7 @@ func (f *Framework) afterEach() {
 
 	summaries := make([]TestDataSummary, 0)
 	if testContext.GatherKubeSystemResourceUsageData {
-		summaries = append(summaries, f.gatherer.stopAndSummarize([]int{50, 90, 99, 100}, f.addonResourceConstraints))
+		summaries = append(summaries, f.gatherer.stopAndSummarize([]int{90, 99}, f.addonResourceConstraints))
 	}
 
 	if testContext.GatherLogsSizes {
diff --git a/test/e2e/log_size_monitoring.go b/test/e2e/log_size_monitoring.go
index 7f251106cc5..5f1eef7663a 100644
--- a/test/e2e/log_size_monitoring.go
+++ b/test/e2e/log_size_monitoring.go
@@ -75,8 +75,15 @@ type LogsSizeVerifier struct {
 	workers       []*LogSizeGatherer
 }
 
+type SingleLogSummary struct {
+	AverageGenerationRate int
+	NumberOfProbes        int
+}
+
+type LogSizeDataTimeseries map[string]map[string][]TimestampedSize
+
 // node -> file -> data
-type LogsSizeDataSummary map[string]map[string][]TimestampedSize
+type LogsSizeDataSummary map[string]map[string]SingleLogSummary
 
 // TODO: make sure that we don't need locking here
 func (s *LogsSizeDataSummary) PrintHumanReadable() string {
@@ -86,12 +93,7 @@ func (s *LogsSizeDataSummary) PrintHumanReadable() string {
 	for k, v := range *s {
 		fmt.Fprintf(w, "%v\t\t\t\n", k)
 		for path, data := range v {
-			if len(data) > 1 {
-				last := data[len(data)-1]
-				first := data[0]
-				rate := (last.size - first.size) / int(last.timestamp.Sub(first.timestamp)/time.Second)
-				fmt.Fprintf(w, "\t%v\t%v\t%v\n", path, rate, len(data))
-			}
+			fmt.Fprintf(w, "\t%v\t%v\t%v\n", path, data.AverageGenerationRate, data.NumberOfProbes)
 		}
 	}
 	w.Flush()
@@ -99,11 +101,11 @@ func (s *LogsSizeDataSummary) PrintHumanReadable() string {
 }
 
 func (s *LogsSizeDataSummary) PrintJSON() string {
-	return "JSON printer not implemented for LogsSizeDataSummary"
+	return prettyPrintJSON(*s)
 }
 
 type LogsSizeData struct {
-	data LogsSizeDataSummary
+	data LogSizeDataTimeseries
 	lock sync.Mutex
 }
 
@@ -116,7 +118,7 @@ type WorkItem struct {
 }
 
 func prepareData(masterAddress string, nodeAddresses []string) LogsSizeData {
-	data := make(LogsSizeDataSummary)
+	data := make(LogSizeDataTimeseries)
 	ips := append(nodeAddresses, masterAddress)
 	for _, ip := range ips {
 		data[ip] = make(map[string][]TimestampedSize)
@@ -170,9 +172,24 @@ func NewLogsVerifier(c *client.Client, stopChannel chan bool) *LogsSizeVerifier
 	return verifier
 }
 
-// PrintData returns a string with formated results
-func (v *LogsSizeVerifier) GetSummary() *LogsSizeDataSummary {
-	return &v.data.data
+// GetSummary returns a summary (average generation rate and number of probes) of the data gathered by LogSizeVerifier
+func (s *LogsSizeVerifier) GetSummary() *LogsSizeDataSummary {
+	result := make(LogsSizeDataSummary)
+	for k, v := range s.data.data {
+		result[k] = make(map[string]SingleLogSummary)
+		for path, data := range v {
+			if len(data) > 1 {
+				last := data[len(data)-1]
+				first := data[0]
+				rate := (last.size - first.size) / int(last.timestamp.Sub(first.timestamp)/time.Second)
+				result[k][path] = SingleLogSummary{
+					AverageGenerationRate: rate,
+					NumberOfProbes:        len(data),
+				}
+			}
+		}
+	}
+	return &result
 }
 
 // Run starts log size gathering. It starts a gorouting for every worker and then blocks until stopChannel is closed
diff --git a/test/e2e/metrics_util.go b/test/e2e/metrics_util.go
index faf99f97743..456f3becd8f 100644
--- a/test/e2e/metrics_util.go
+++ b/test/e2e/metrics_util.go
@@ -70,7 +70,7 @@ func (m *metricsForE2E) PrintHumanReadable() string {
 }
 
 func (m *metricsForE2E) PrintJSON() string {
-	return "JSON printer not implemented for Metrics"
+	return prettyPrintJSON(*m)
 }
 
 var InterestingApiServerMetrics = []string{
@@ -402,10 +402,12 @@ func VerifySchedulerLatency(c *client.Client) error {
 func prettyPrintJSON(metrics interface{}) string {
 	output := &bytes.Buffer{}
 	if err := json.NewEncoder(output).Encode(metrics); err != nil {
+		Logf("Error building encoder: %v", err)
 		return ""
 	}
 	formatted := &bytes.Buffer{}
 	if err := json.Indent(formatted, output.Bytes(), "", "  "); err != nil {
+		Logf("Error indenting: %v", err)
 		return ""
 	}
 	return string(formatted.Bytes())
diff --git a/test/e2e/resource_usage_gatherer.go b/test/e2e/resource_usage_gatherer.go
index 563c65079d6..e2b1cb5c6ec 100644
--- a/test/e2e/resource_usage_gatherer.go
+++ b/test/e2e/resource_usage_gatherer.go
@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"math"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 	"text/tabwriter"
@@ -48,12 +49,13 @@ type containerResourceGatherer struct {
 }
 
 type singleContainerSummary struct {
-	name string
-	cpu  float64
-	mem  int64
+	Name string
+	Cpu  float64
+	Mem  int64
 }
 
-type ResourceUsageSummary map[int][]singleContainerSummary
+// we can't have int here, as JSON does not accept integer keys.
+type ResourceUsageSummary map[string][]singleContainerSummary
 
 func (s *ResourceUsageSummary) PrintHumanReadable() string {
 	buf := &bytes.Buffer{}
@@ -62,7 +64,7 @@ func (s *ResourceUsageSummary) PrintHumanReadable() string {
 		buf.WriteString(fmt.Sprintf("%v percentile:\n", perc))
 		fmt.Fprintf(w, "container\tcpu(cores)\tmemory(MB)\n")
 		for _, summary := range summaries {
-			fmt.Fprintf(w, "%q\t%.3f\t%.2f\n", summary.name, summary.cpu, float64(summary.mem)/(1024*1024))
+			fmt.Fprintf(w, "%q\t%.3f\t%.2f\n", summary.Name, summary.Cpu, float64(summary.Mem)/(1024*1024))
 		}
 		w.Flush()
 	}
@@ -70,7 +72,7 @@ func (s *ResourceUsageSummary) PrintHumanReadable() string {
 }
 
 func (s *ResourceUsageSummary) PrintJSON() string {
-	return "JSON printer not implemented for ResourceUsageSummary"
+	return prettyPrintJSON(*s)
 }
 
 func (g *containerResourceGatherer) startGatheringData(c *client.Client, period time.Duration) {
@@ -115,10 +117,10 @@ func (g *containerResourceGatherer) stopAndSummarize(percentiles []int, constrai
 	for _, perc := range percentiles {
 		for _, name := range sortedKeys {
 			usage := stats[perc][name]
-			summary[perc] = append(summary[perc], singleContainerSummary{
-				name: name,
-				cpu:  usage.CPUUsageInCores,
-				mem:  usage.MemoryWorkingSetInBytes,
+			summary[strconv.Itoa(perc)] = append(summary[strconv.Itoa(perc)], singleContainerSummary{
+				Name: name,
+				Cpu:  usage.CPUUsageInCores,
+				Mem:  usage.MemoryWorkingSetInBytes,
 			})
 			// Verifying 99th percentile of resource usage
 			if perc == 99 {