diff --git a/pkg/kubelet/server/stats/types.go b/pkg/kubelet/server/stats/types.go
index f46aee11c2b..a75880d047e 100644
--- a/pkg/kubelet/server/stats/types.go
+++ b/pkg/kubelet/server/stats/types.go
@@ -17,7 +17,6 @@ limitations under the License.
 package stats
 
 import (
-	"k8s.io/kubernetes/pkg/api/resource"
 	"k8s.io/kubernetes/pkg/api/unversioned"
 )
 
@@ -39,6 +38,8 @@ type NodeStats struct {
 	// Stats of system daemons tracked as raw containers.
 	// The system containers are named according to the SystemContainer* constants.
 	SystemContainers []ContainerStats `json:"systemContainers,omitempty" patchStrategy:"merge" patchMergeKey:"name"`
+	// The time at which data collection for the node-scoped (i.e. aggregate) stats was (re)started.
+	StartTime unversioned.Time `json:"startTime"`
 	// Stats pertaining to CPU resources.
 	CPU *CPUStats `json:"cpu,omitempty"`
 	// Stats pertaining to memory (RAM) resources.
@@ -62,7 +63,9 @@ const (
 // PodStats holds pod-level unprocessed sample stats.
 type PodStats struct {
 	// Reference to the measured Pod.
-	PodRef NonLocalObjectReference `json:"podRef"`
+	PodRef PodReference `json:"podRef"`
+	// The time at which data collection for the pod-scoped (e.g. network) stats was (re)started.
+	StartTime unversioned.Time `json:"startTime"`
 	// Stats of containers in the measured pod.
 	Containers []ContainerStats `json:"containers" patchStrategy:"merge" patchMergeKey:"name"`
 	// Stats pertaining to network resources.
@@ -76,6 +79,8 @@ type PodStats struct {
 type ContainerStats struct {
 	// Reference to the measured container.
 	Name string `json:"name"`
+	// The time at which data collection for this container was (re)started.
+	StartTime unversioned.Time `json:"startTime"`
 	// Stats pertaining to CPU resources.
 	CPU *CPUStats `json:"cpu,omitempty"`
 	// Stats pertaining to memory (RAM) resources.
@@ -86,46 +91,49 @@ type ContainerStats struct {
 	// Stats pertaining to container logs usage of filesystem resources.
 	// Logs.UsedBytes is the number of bytes used for the container logs.
 	Logs *FsStats `json:"logs,omitempty"`
+	// User defined metrics are arbitrary metrics exposed by containers in pods.
+	UserDefinedMetrics []UserDefinedMetric `json:"userDefinedMetrics,omitmepty" patchStrategy:"merge" patchMergeKey:"name"`
 }
 
-// NonLocalObjectReference contains enough information to locate the referenced object.
-type NonLocalObjectReference struct {
+// PodReference contains enough information to locate the referenced pod.
+type PodReference struct {
 	Name      string `json:"name"`
 	Namespace string `json:"namespace"`
+	UID       string `json:"uid"`
 }
 
 // NetworkStats contains data about network resources.
 type NetworkStats struct {
 	// Cumulative count of bytes received.
-	RxBytes *resource.Quantity `json:"rxBytes,omitempty"`
+	RxBytes *uint64 `json:"rxBytes,omitempty"`
 	// Cumulative count of receive errors encountered.
-	RxErrors *int64 `json:"rxErrors,omitempty"`
+	RxErrors *uint64 `json:"rxErrors,omitempty"`
 	// Cumulative count of bytes transmitted.
-	TxBytes *resource.Quantity `json:"txBytes,omitempty"`
+	TxBytes *uint64 `json:"txBytes,omitempty"`
 	// Cumulative count of transmit errors encountered.
-	TxErrors *int64 `json:"txErrors,omitempty"`
+	TxErrors *uint64 `json:"txErrors,omitempty"`
 }
 
 // CPUStats contains data about CPU usage.
 type CPUStats struct {
 	// Total CPU usage (sum of all cores) averaged over the sample window.
-	// The "core" unit can be interpreted as CPU core-seconds per second.
-	UsageCores *resource.Quantity `json:"usageCores,omitempty"`
+	// The "core" unit can be interpreted as CPU core-nanoseconds per second.
+	UsageNanoCores *uint64 `json:"usageNanoCores,omitempty"`
 	// Cumulative CPU usage (sum of all cores) since object creation.
-	UsageCoreSeconds *resource.Quantity `json:"usageCoreSeconds,omitempty"`
+	UsageCoreNanoSeconds *uint64 `json:"usageCoreNanoSeconds,omitempty"`
 }
 
 // MemoryStats contains data about memory usage.
 type MemoryStats struct {
 	// Total memory in use. This includes all memory regardless of when it was accessed.
-	UsageBytes *resource.Quantity `json:"usageBytes,omitempty"`
+	UsageBytes *uint64 `json:"usageBytes,omitempty"`
 	// The amount of working set memory. This includes recently accessed memory,
 	// dirty memory, and kernel memory. UsageBytes is <= TotalBytes.
-	WorkingSetBytes *resource.Quantity `json:"workingSetBytes,omitempty"`
+	WorkingSetBytes *uint64 `json:"workingSetBytes,omitempty"`
 	// Cumulative number of minor page faults.
-	PageFaults *int64 `json:"pageFaults,omitempty"`
+	PageFaults *uint64 `json:"pageFaults,omitempty"`
 	// Cumulative number of major page faults.
-	MajorPageFaults *int64 `json:"majorPageFaults,omitempty"`
+	MajorPageFaults *uint64 `json:"majorPageFaults,omitempty"`
 }
 
 // VolumeStats contains data about Volume filesystem usage.
@@ -139,11 +147,48 @@ type VolumeStats struct {
 // FsStats contains data about filesystem usage.
 type FsStats struct {
 	// AvailableBytes represents the storage space available (bytes) for the filesystem.
-	AvailableBytes *resource.Quantity `json:"availableBytes,omitempty"`
+	AvailableBytes *uint64 `json:"availableBytes,omitempty"`
 	// CapacityBytes represents the total capacity (bytes) of the filesystems underlying storage.
-	CapacityBytes *resource.Quantity `json:"capacityBytes,omitempty"`
+	CapacityBytes *uint64 `json:"capacityBytes,omitempty"`
 	// UsedBytes represents the bytes used for a specific task on the filesystem.
 	// This may differ from the total bytes used on the filesystem and may not equal CapacityBytes - AvailableBytes.
 	// e.g. For ContainerStats.Rootfs this is the bytes used by the container rootfs on the filesystem.
-	UsedBytes *resource.Quantity `json:"usedBytes,omitempty"`
+	UsedBytes *uint64 `json:"usedBytes,omitempty"`
+}
+
+// UserDefinedMetricType defines how the metric should be interpreted by the user.
+type UserDefinedMetricType string
+
+const (
+	// Instantaneous value. May increase or decrease.
+	MetricGauge UserDefinedMetricType = "gauge"
+
+	// A counter-like value that is only expected to increase.
+	MetricCumulative UserDefinedMetricType = "cumulative"
+
+	// Rate over a time period.
+	MetricDelta UserDefinedMetricType = "delta"
+)
+
+// UserDefinedMetricDescriptor contains metadata that describes a user defined metric.
+type UserDefinedMetricDescriptor struct {
+	// The name of the metric.
+	Name string `json:"name"`
+
+	// Type of the metric.
+	Type UserDefinedMetricType `json:"type"`
+
+	// Display Units for the stats.
+	Units string `json:"units"`
+
+	// Metadata labels associated with this metric.
+	Labels map[string]string `json:"labels,omitempty"`
+}
+
+// UserDefinedMetric represents a metric defined and generate by users.
+type UserDefinedMetric struct {
+	UserDefinedMetricDescriptor `json:",inline"`
+	// Value of the metric. Float64s have 53 bit precision.
+	// We do not forsee any metrics exceeding that value.
+	Value float64 `json:"value"`
 }