Refactor on metrics so that names for all the views are tracked

Author: Xuewei Zhang

pkg/problemmetrics/problem_metrics.go

@@ -49,7 +49,8 @@ func NewProblemMetricsManagerOrDie() *ProblemMetricsManager {
 
 	var err error
 	pmm.problemCounter, err = metrics.NewInt64Metric(
-		"problem_counter",
+		metrics.ProblemCounterID,
+		string(metrics.ProblemCounterID),
 		"Number of times a specific type of problem have occurred.",
 		"1",
 		metrics.Sum,
@@ -59,7 +60,8 @@ func NewProblemMetricsManagerOrDie() *ProblemMetricsManager {
 	}
 
 	pmm.problemGauge, err = metrics.NewInt64Metric(
-		"problem_gauge",
+		metrics.ProblemGaugeID,
+		string(metrics.ProblemGaugeID),
 		"Whether a specific type of problem is affecting the node or not.",
 		"1",
 		metrics.LastValue,

pkg/systemstatsmonitor/disk_collector.go

@@ -49,7 +49,8 @@ func NewDiskCollectorOrDie(diskConfig *ssmtypes.DiskStatsConfig) *diskCollector
 
 	// Use metrics.Sum aggregation method to ensure the metric is a counter/cumulative metric.
 	dc.mIOTime, err = metrics.NewInt64Metric(
-		diskConfig.MetricsConfigs["disk/io_time"].DisplayName,
+		metrics.DiskIOTimeID,
+		diskConfig.MetricsConfigs[string(metrics.DiskIOTimeID)].DisplayName,
 		"The IO time spent on the disk",
 		"second",
 		metrics.Sum,
@@ -60,7 +61,8 @@ func NewDiskCollectorOrDie(diskConfig *ssmtypes.DiskStatsConfig) *diskCollector
 
 	// Use metrics.Sum aggregation method to ensure the metric is a counter/cumulative metric.
 	dc.mWeightedIO, err = metrics.NewInt64Metric(
-		diskConfig.MetricsConfigs["disk/weighted_io"].DisplayName,
+		metrics.DiskWeightedIOID,
+		diskConfig.MetricsConfigs[string(metrics.DiskWeightedIOID)].DisplayName,
 		"The weighted IO on the disk",
 		"second",
 		metrics.Sum,
@@ -70,7 +72,8 @@ func NewDiskCollectorOrDie(diskConfig *ssmtypes.DiskStatsConfig) *diskCollector
 	}
 
 	dc.mAvgQueueLen, err = metrics.NewFloat64Metric(
-		diskConfig.MetricsConfigs["disk/avg_queue_len"].DisplayName,
+		metrics.DiskAvgQueueLenID,
+		diskConfig.MetricsConfigs[string(metrics.DiskAvgQueueLenID)].DisplayName,
 		"The average queue length on the disk",
 		"second",
 		metrics.LastValue,

pkg/systemstatsmonitor/host_collector.go

@@ -26,12 +26,12 @@ import (
 )
 
 type hostCollector struct {
-	tags       map[string]string
-	uptime     *metrics.Int64Metric
+	tags   map[string]string
+	uptime *metrics.Int64Metric
 }
 
 func NewHostCollectorOrDie(hostConfig *ssmtypes.HostStatsConfig) *hostCollector {
-	hc := hostCollector{map[string]string{}, nil, 0}
+	hc := hostCollector{map[string]string{}, nil}
 
 	kernelVersion, err := host.KernelVersion()
 	if err != nil {
@@ -48,7 +48,8 @@ func NewHostCollectorOrDie(hostConfig *ssmtypes.HostStatsConfig) *hostCollector
 	// Use metrics.Sum aggregation method to ensure the metric is a counter/cumulative metric.
 	if hostConfig.MetricsConfigs["host/uptime"].DisplayName != "" {
 		hc.uptime, err = metrics.NewInt64Metric(
-			hostConfig.MetricsConfigs["host/uptime"].DisplayName,
+			metrics.HostUptimeID,
+			hostConfig.MetricsConfigs[string(metrics.HostUptimeID)].DisplayName,
 			"The uptime of the operating system",
 			"second",
 			metrics.LastValue,
@@ -75,4 +76,4 @@ func (hc *hostCollector) collect() {
 	if hc.uptime != nil {
 		hc.uptime.Record(hc.tags, int64(uptime))
 	}
-}
+}

pkg/types/types.go

@@ -131,3 +131,19 @@ type ProblemDaemonHandler struct {
 	// CmdOptionDescription explains how to configure the problem daemon from command line arguments.
 	CmdOptionDescription string
 }
+
+// ExporterType is the type of the exporter.
+type ExporterType string
+
+// ExporterConfigPathMap represents configurations on all types of exporters:
+// 1) Each key represents a type of exporter.
+// 2) Each value represents the config file path for the exporter.
+type ExporterConfigPathMap map[ExporterType]*string
+
+// ExporterHandler represents the initialization handler for a type of exporter.
+type ExporterHandler struct {
+	// CreateExporterOrDie initializes an exporter, panic if error occurs.
+	CreateExporterOrDie func(string) Exporter
+	// CmdOptionDescription explains how to configure the exporter from command line arguments.
+	CmdOptionDescription string
+}

pkg/util/metrics/helpers.go

@@ -16,15 +16,12 @@ limitations under the License.
 package metrics
 
 import (
-	"context"
 	"fmt"
 	"strings"
 	"sync"
 
 	pcm "github.com/prometheus/client_model/go"
 	"github.com/prometheus/common/expfmt"
-	"go.opencensus.io/stats"
-	"go.opencensus.io/stats/view"
 	"go.opencensus.io/tag"
 )
 
@@ -47,152 +44,6 @@ const (
 	Sum Aggregation = "Sum"
 )
 
-// Int64MetricRepresentation represents a snapshot of an int64 metrics.
-// This is used for inspecting metric internals.
-type Int64MetricRepresentation struct {
-	// Name is the metric name.
-	Name string
-	// Labels contains all metric labels in key-value pair format.
-	Labels map[string]string
-	// Value is the value of the metric.
-	Value int64
-}
-
-// Int64Metric represents an int64 metric.
-type Int64Metric struct {
-	name    string
-	measure *stats.Int64Measure
-}
-
-// NewInt64Metric create a Int64Metric metric, returns nil when name is empty.
-func NewInt64Metric(name string, description string, unit string, aggregation Aggregation, tagNames []string) (*Int64Metric, error) {
-	if name == "" {
-		return nil, nil
-	}
-
-	tagKeys, err := getTagKeysFromNames(tagNames)
-	if err != nil {
-		return nil, fmt.Errorf("failed to create metric %q because of tag creation failure: %v", name, err)
-	}
-
-	var aggregationMethod *view.Aggregation
-	switch aggregation {
-	case LastValue:
-		aggregationMethod = view.LastValue()
-	case Sum:
-		aggregationMethod = view.Sum()
-	default:
-		return nil, fmt.Errorf("unknown aggregation option %q", aggregation)
-	}
-
-	measure := stats.Int64(name, description, unit)
-	newView := &view.View{
-		Name:        name,
-		Measure:     measure,
-		Description: description,
-		Aggregation: aggregationMethod,
-		TagKeys:     tagKeys,
-	}
-	view.Register(newView)
-
-	metric := Int64Metric{name, measure}
-	return &metric, nil
-}
-
-// Record records a measurement for the metric, with provided tags as metric labels.
-func (metric *Int64Metric) Record(tags map[string]string, measurement int64) error {
-	var mutators []tag.Mutator
-
-	tagMapMutex.RLock()
-	defer tagMapMutex.RUnlock()
-
-	for tagName, tagValue := range tags {
-		tagKey, ok := tagMap[tagName]
-		if !ok {
-			return fmt.Errorf("referencing none existing tag %q in metric %q", tagName, metric.name)
-		}
-		mutators = append(mutators, tag.Upsert(tagKey, tagValue))
-	}
-
-	return stats.RecordWithTags(
-		context.Background(),
-		mutators,
-		metric.measure.M(measurement))
-}
-
-// Float64MetricRepresentation represents a snapshot of a float64 metrics.
-// This is used for inspecting metric internals.
-type Float64MetricRepresentation struct {
-	// Name is the metric name.
-	Name string
-	// Labels contains all metric labels in key-value pair format.
-	Labels map[string]string
-	// Value is the value of the metric.
-	Value float64
-}
-
-// Float64Metric represents an float64 metric.
-type Float64Metric struct {
-	name    string
-	measure *stats.Float64Measure
-}
-
-// NewFloat64Metric create a Float64Metric metrics, returns nil when name is empty.
-func NewFloat64Metric(name string, description string, unit string, aggregation Aggregation, tagNames []string) (*Float64Metric, error) {
-	if name == "" {
-		return nil, nil
-	}
-
-	tagKeys, err := getTagKeysFromNames(tagNames)
-	if err != nil {
-		return nil, fmt.Errorf("failed to create metric %q because of tag creation failure: %v", name, err)
-	}
-
-	var aggregationMethod *view.Aggregation
-	switch aggregation {
-	case LastValue:
-		aggregationMethod = view.LastValue()
-	case Sum:
-		aggregationMethod = view.Sum()
-	default:
-		return nil, fmt.Errorf("unknown aggregation option %q", aggregation)
-	}
-
-	measure := stats.Float64(name, description, unit)
-	newView := &view.View{
-		Name:        name,
-		Measure:     measure,
-		Description: description,
-		Aggregation: aggregationMethod,
-		TagKeys:     tagKeys,
-	}
-	view.Register(newView)
-
-	metric := Float64Metric{name, measure}
-	return &metric, nil
-}
-
-// Record records a measurement for the metric, with provided tags as metric labels.
-func (metric *Float64Metric) Record(tags map[string]string, measurement float64) error {
-	var mutators []tag.Mutator
-
-	tagMapMutex.RLock()
-	defer tagMapMutex.RUnlock()
-
-	for tagName, tagValue := range tags {
-		tagKey, ok := tagMap[tagName]
-		if !ok {
-			return fmt.Errorf("referencing none existing tag %q in metric %q", tagName, metric.name)
-		}
-		mutators = append(mutators, tag.Upsert(tagKey, tagValue))
-	}
-
-	return stats.RecordWithTags(
-		context.Background(),
-		mutators,
-		metric.measure.M(measurement))
-}
-
 func getTagKeysFromNames(tagNames []string) ([]tag.Key, error) {
 	tagMapMutex.Lock()
 	defer tagMapMutex.Unlock()

pkg/util/metrics/metric.go

@@ -0,0 +1,60 @@
+/*
+Copyright 2019 The Kubernetes Authors All rights reserved.
+
+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 metrics
+
+import (
+	"sync"
+)
+
+const (
+	ProblemCounterID  MetricID = "problem_counter"
+	ProblemGaugeID    MetricID = "problem_gauge"
+	DiskIOTimeID      MetricID = "disk/io_time"
+	DiskWeightedIOID  MetricID = "disk/weighted_io"
+	DiskAvgQueueLenID MetricID = "disk/avg_queue_len"
+	HostUptimeID      MetricID = "host/uptime"
+)
+
+var MetricMap MetricMapping
+
+func init() {
+	MetricMap.mapMutex.Lock()
+	defer MetricMap.mapMutex.Unlock()
+
+	MetricMap.viewNameToMetricIDMap = make(map[string]MetricID)
+}
+
+type MetricID string
+
+type MetricMapping struct {
+	viewNameToMetricIDMap map[string]MetricID
+	mapMutex              sync.RWMutex
+}
+
+func (mm *MetricMapping) AddMapping(metricID MetricID, viewName string) {
+	mm.mapMutex.Lock()
+	defer mm.mapMutex.Unlock()
+
+	mm.viewNameToMetricIDMap[viewName] = metricID
+}
+
+func (mm *MetricMapping) ViewNameToMetricID(viewName string) (MetricID, bool) {
+	mm.mapMutex.RLock()
+	defer mm.mapMutex.RUnlock()
+
+	id, ok := mm.viewNameToMetricIDMap[viewName]
+	return id, ok
+}