Updates to /targets and /rules (scrape duration, last evaluation time) (#4722)

* Add evaluationTimestamp (Last Evaluation) column to display on /rules
Signed-off-by: Will Hegedus <wbhegedus@liberty.edu>

* Add lastScrapeDuration ("Scrape Duration") to display on /targets
Signed-off-by: Will Hegedus <wbhegedus@liberty.edu>

* Updates based on Julius' feedback

Signed-off-by: Will Hegedus <wbhegedus@liberty.edu>

* Update to set timestamp to when eval started (after eval completes)

Signed-off-by: Will Hegedus <wbhegedus@liberty.edu>

* Update /rules to display time since last evaluation

Signed-off-by: Will Hegedus <wbhegedus@liberty.edu>

* Re-order Last Eval/Eval Time to be consistent with targets page

Signed-off-by: Will Hegedus <wbhegedus@liberty.edu>

rules/alerting.go

@@ -118,13 +118,15 @@ type AlertingRule struct {
 	labels labels.Labels
 	// Non-identifying key/value pairs.
 	annotations labels.Labels
-	// Time in seconds taken to evaluate rule.
-	evaluationDuration time.Duration
 	// true if old state has been restored. We start persisting samples for ALERT_FOR_STATE
 	// only after the restoration.
 	restored bool
 	// Protects the below.
 	mtx sync.Mutex
+	// Time in seconds taken to evaluate rule.
+	evaluationDuration time.Duration
+	// Timestamp of last evaluation of rule.
+	evaluationTimestamp time.Time
 	// The health of the alerting rule.
 	health RuleHealth
 	// The last error seen by the alerting rule.
@@ -258,6 +260,20 @@ func (r *AlertingRule) GetEvaluationDuration() time.Duration {
 	return r.evaluationDuration
 }
 
+// SetEvaluationTimestamp updates evaluationTimestamp to the timestamp of when the rule was last evaluated.
+func (r *AlertingRule) SetEvaluationTimestamp(ts time.Time) {
+	r.mtx.Lock()
+	defer r.mtx.Unlock()
+	r.evaluationTimestamp = ts
+}
+
+// GetEvaluationTimestamp returns the time the evaluation took place.
+func (r *AlertingRule) GetEvaluationTimestamp() time.Time {
+	r.mtx.Lock()
+	defer r.mtx.Unlock()
+	return r.evaluationTimestamp
+}
+
 // SetRestored updates the restoration state of the alerting rule.
 func (r *AlertingRule) SetRestored(restored bool) {
 	r.restored = restored

rules/manager.go

@@ -160,6 +160,8 @@ type Rule interface {
 	Health() RuleHealth
 	SetEvaluationDuration(time.Duration)
 	GetEvaluationDuration() time.Duration
+	SetEvaluationTimestamp(time.Time)
+	GetEvaluationTimestamp() time.Time
 	// HTMLSnippet returns a human-readable string representation of the rule,
 	// decorated with HTML elements for use the web frontend.
 	HTMLSnippet(pathPrefix string) html_template.HTML
@@ -173,8 +175,9 @@ type Group struct {
 	rules                []Rule
 	seriesInPreviousEval []map[string]labels.Labels // One per Rule.
 	opts                 *ManagerOptions
-	evaluationDuration   time.Duration
 	mtx                  sync.Mutex
+	evaluationDuration   time.Duration
+	evaluationTimestamp  time.Time
 
 	shouldRestore bool
 
@@ -232,6 +235,7 @@ func (g *Group) run(ctx context.Context) {
 
 		iterationDuration.Observe(timeSinceStart.Seconds())
 		g.SetEvaluationDuration(timeSinceStart)
+		g.SetEvaluationTimestamp(start)
 	}
 
 	// The assumption here is that since the ticker was started after having
@@ -311,6 +315,20 @@ func (g *Group) SetEvaluationDuration(dur time.Duration) {
 	g.evaluationDuration = dur
 }
 
+// SetEvaluationTimestamp updates evaluationTimestamp to the timestamp of when the rule group was last evaluated.
+func (g *Group) SetEvaluationTimestamp(ts time.Time) {
+	g.mtx.Lock()
+	defer g.mtx.Unlock()
+	g.evaluationTimestamp = ts
+}
+
+// GetEvaluationTimestamp returns the time the last evaluation of the rule group took place.
+func (g *Group) GetEvaluationTimestamp() time.Time {
+	g.mtx.Lock()
+	defer g.mtx.Unlock()
+	return g.evaluationTimestamp
+}
+
 // evalTimestamp returns the immediately preceding consistently slotted evaluation time.
 func (g *Group) evalTimestamp() time.Time {
 	var (
@@ -377,6 +395,7 @@ func (g *Group) Eval(ctx context.Context, ts time.Time) {
 				sp.Finish()
 				evalDuration.Observe(time.Since(t).Seconds())
 				rule.SetEvaluationDuration(time.Since(t))
+				rule.SetEvaluationTimestamp(t)
 			}(time.Now())
 
 			evalTotal.Inc()

rules/recording.go

@@ -38,8 +38,11 @@ type RecordingRule struct {
 	mtx sync.Mutex
 	// The health of the recording rule.
 	health RuleHealth
+	// Timestamp of last evaluation of the recording rule.
+	evaluationTimestamp time.Time
 	// The last error seen by the recording rule.
 	lastError error
+	// Duration of how long it took to evaluate the recording rule.
 	evaluationDuration time.Duration
 }
 
@@ -156,6 +159,20 @@ func (rule *RecordingRule) GetEvaluationDuration() time.Duration {
 	return rule.evaluationDuration
 }
 
+// SetEvaluationTimestamp updates evaluationTimestamp to the timestamp of when the rule was last evaluated.
+func (rule *RecordingRule) SetEvaluationTimestamp(ts time.Time) {
+	rule.mtx.Lock()
+	defer rule.mtx.Unlock()
+	rule.evaluationTimestamp = ts
+}
+
+// GetEvaluationTimestamp returns the time the evaluation took place.
+func (rule *RecordingRule) GetEvaluationTimestamp() time.Time {
+	rule.mtx.Lock()
+	defer rule.mtx.Unlock()
+	return rule.evaluationTimestamp
+}
+
 // HTMLSnippet returns an HTML snippet representing this rule.
 func (rule *RecordingRule) HTMLSnippet(pathPrefix string) template.HTML {
 	ruleExpr := rule.vector.String()

scrape/target.go

@@ -56,6 +56,7 @@ type Target struct {
 	mtx                sync.RWMutex
 	lastError          error
 	lastScrape         time.Time
+	lastScrapeDuration time.Duration
 	health             TargetHealth
 	metadata           metricMetadataStore
 }
@@ -206,6 +207,7 @@ func (t *Target) report(start time.Time, dur time.Duration, err error) {
 
 	t.lastError = err
 	t.lastScrape = start
+	t.lastScrapeDuration = dur
 }
 
 // LastError returns the error encountered during the last scrape.
@@ -224,6 +226,14 @@ func (t *Target) LastScrape() time.Time {
 	return t.lastScrape
 }
 
+// LastScrapeDuration returns how long the last scrape of the target took.
+func (t *Target) LastScrapeDuration() time.Duration {
+	t.mtx.RLock()
+	defer t.mtx.RUnlock()
+
+	return t.lastScrapeDuration
+}
+
 // Health returns the last known health state of the target.
 func (t *Target) Health() TargetHealth {
 	t.mtx.RLock()

web/ui/templates/rules.html

@@ -10,6 +10,7 @@
         <thead>
           <tr>
             <td colspan="3"><h2><a href="#{{reReplaceAll "([^a-zA-Z0-9])" "$1" .Name}}" name="{{reReplaceAll "([^a-zA-Z0-9])" "$1" .Name}}">{{.Name}}</h2></td>
+            <td><h2>{{if .GetEvaluationTimestamp.IsZero}}Never{{else}}{{since .GetEvaluationTimestamp}} ago{{end}}</h2></td>
             <td><h2>{{humanizeDuration .GetEvaluationDuration.Seconds}}</h2></td>
           </tr>
         </thead>
@@ -18,6 +19,7 @@
             <td style="font-weight:bold">Rule</td>
             <td style="font-weight:bold">State</td>
             <td style="font-weight:bold">Error</td>
+            <td style="font-weight:bold">Last Evaluation</td>
             <td style="font-weight:bold">Evaluation Time</td>
           </tr>
           {{range .Rules}}
@@ -33,6 +35,9 @@
               <span class="alert alert-danger state_indicator">{{.LastError}}</span>
               {{end}}
             </td>
+            <td>
+              {{if .GetEvaluationTimestamp.IsZero}}Never{{else}}{{since .GetEvaluationTimestamp}} ago{{end}}
+            </td>
             <td>{{humanizeDuration .GetEvaluationDuration.Seconds}}</td>
           </tr>
           {{end}}

web/ui/templates/targets.html

@@ -32,6 +32,7 @@
             <th>State</th>
             <th>Labels</th>
             <th>Last Scrape</th>
+            <th>Scrape Duration</th>
             <th>Error</th>
           </tr>
         </thead>
@@ -64,6 +65,9 @@
             <td class="last-scrape">
               {{if .LastScrape.IsZero}}Never{{else}}{{since .LastScrape}} ago{{end}}
             </td>
+            <td class="scrape-duration">
+              {{humanizeDuration .LastScrapeDuration.Seconds}}
+            </td>
             <td class="errors">
               {{if .LastError}}
               <span class="alert alert-danger state_indicator">{{.LastError}}</span>