Include curator status in web heads-up-display.

appstate/appstate.go

@@ -29,4 +29,5 @@ type ApplicationState struct {
 	Storage       metric.Storage
 	TargetManager retrieval.TargetManager
 	BuildInfo     map[string]string
+	CurationState chan metric.CurationState
 }

main.go

@@ -15,7 +15,6 @@ package main
 
 import (
 	"flag"
-	"fmt"
 	"github.com/prometheus/prometheus/appstate"
 	"github.com/prometheus/prometheus/config"
 	"github.com/prometheus/prometheus/retrieval"
@@ -32,8 +31,6 @@ import (
 
 // Commandline flags.
 var (
-	_ = fmt.Sprintf("")
-
 	printVersion                 = flag.Bool("version", false, "print version information")
 	configFile                   = flag.String("configFile", "prometheus.conf", "Prometheus configuration file name.")
 	metricsStoragePath           = flag.String("metricsStoragePath", "/tmp/metrics", "Base path for metrics storage.")
@@ -117,11 +114,12 @@ func main() {
 	}
 
 	appState := &appstate.ApplicationState{
+		BuildInfo:     BuildInfo,
 		Config:        conf,
+		CurationState: make(chan metric.CurationState),
 		RuleManager:   ruleManager,
 		Storage:       ts,
 		TargetManager: targetManager,
-		BuildInfo:     BuildInfo,
 	}
 
 	web.StartServing(appState)

storage/metric/curator.go

@@ -26,6 +26,15 @@ import (
 	"time"
 )
 
+// CurationState contains high-level curation state information for the
+// heads-up-display.
+type CurationState struct {
+	Active      bool
+	Name        string
+	Limit       time.Duration
+	Fingerprint model.Fingerprint
+}
+
 // watermarkFilter determines whether to include or exclude candidate
 // values from the curation process by virtue of how old the high watermark is.
 type watermarkFilter struct {
@@ -43,6 +52,8 @@ type watermarkFilter struct {
 	stop chan bool
 	// stopAt is used to determine the elegibility of series for compaction.
 	stopAt time.Time
+	// status is the outbound channel for notifying the status page of its state.
+	status chan CurationState
 }
 
 // curator is responsible for effectuating a given curation policy across the
@@ -97,7 +108,7 @@ func newCurator() curator {
 // curated.
 // curationState is the on-disk store where the curation remarks are made for
 // how much progress has been made.
-func (c curator) run(ignoreYoungerThan time.Duration, instant time.Time, processor processor, curationState, samples, watermarks *leveldb.LevelDBPersistence) (err error) {
+func (c curator) run(ignoreYoungerThan time.Duration, instant time.Time, processor processor, curationState, samples, watermarks *leveldb.LevelDBPersistence, status chan CurationState) (err error) {
 	defer func(t time.Time) {
 		duration := float64(time.Since(t))
 
@@ -113,6 +124,11 @@ func (c curator) run(ignoreYoungerThan time.Duration, instant time.Time, process
 		curationDuration.IncrementBy(labels, duration)
 		curationDurations.Add(labels, duration)
 	}(time.Now())
+	defer func() {
+		status <- CurationState{
+			Active: false,
+		}
+	}()
 
 	iterator := samples.NewIterator(true)
 	defer iterator.Close()
@@ -130,8 +146,9 @@ func (c curator) run(ignoreYoungerThan time.Duration, instant time.Time, process
 
 	filter := watermarkFilter{
 		curationState:     curationState,
-		processor:         processor,
 		ignoreYoungerThan: ignoreYoungerThan,
+		processor:         processor,
+		status:            status,
 		stop:              c.stop,
 		stopAt:            instant.Add(-1 * ignoreYoungerThan),
 	}
@@ -235,6 +252,8 @@ func getCurationRemark(states raw.Persistence, processor processor, ignoreYounge
 }
 
 func (w watermarkFilter) Filter(key, value interface{}) (r storage.FilterResult) {
+	fingerprint := key.(model.Fingerprint)
+
 	defer func() {
 		labels := map[string]string{
 			cutOff:        fmt.Sprint(w.ignoreYoungerThan),
@@ -245,11 +264,19 @@ func (w watermarkFilter) Filter(key, value interface{}) (r storage.FilterResult)
 		curationFilterOperations.Increment(labels)
 	}()
 
+	defer func() {
+		w.status <- CurationState{
+			Active:      true,
+			Name:        w.processor.Name(),
+			Limit:       w.ignoreYoungerThan,
+			Fingerprint: fingerprint,
+		}
+	}()
+
 	if w.shouldStop() {
 		return storage.STOP
 	}
 
-	fingerprint := key.(model.Fingerprint)
 	curationRemark, err := getCurationRemark(w.curationState, w.processor, w.ignoreYoungerThan, fingerprint)
 	if err != nil {
 		return

storage/metric/processor_test.go

@@ -845,8 +845,11 @@ func TestCuratorCompactionProcessor(t *testing.T) {
 		}
 		defer samples.Close()
 
+		updates := make(chan CurationState, 100)
+		defer close(updates)
+
 		c := newCurator()
-		err = c.run(scenario.in.ignoreYoungerThan, testInstant, scenario.in.processor, curatorStates, samples, watermarkStates)
+		err = c.run(scenario.in.ignoreYoungerThan, testInstant, scenario.in.processor, curatorStates, samples, watermarkStates, updates)
 		if err != nil {
 			t.Fatal(err)
 		}

web/status.go

@@ -17,6 +17,7 @@ import (
 	"flag"
 	"github.com/prometheus/prometheus/appstate"
 	"github.com/prometheus/prometheus/retrieval"
+	"github.com/prometheus/prometheus/storage/metric"
 	"net/http"
 )
 
@@ -27,20 +28,22 @@ type PrometheusStatus struct {
 	TargetPools map[string]*retrieval.TargetPool
 	BuildInfo   map[string]string
 	Flags       map[string]string
+	Curation    metric.CurationState
 }
 
 type StatusHandler struct {
-	appState *appstate.ApplicationState
+	appState         *appstate.ApplicationState
+	PrometheusStatus *PrometheusStatus
 }
 
-func (h *StatusHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+func (h *StatusHandler) Run() {
 	flags := map[string]string{}
 
 	flag.VisitAll(func(f *flag.Flag) {
 		flags[f.Name] = f.Value.String()
 	})
 
-	status := &PrometheusStatus{
+	h.PrometheusStatus = &PrometheusStatus{
 		Config:      h.appState.Config.ToString(0),
 		Rules:       "TODO: list rules here",
 		Status:      "TODO: add status information here",
@@ -48,5 +51,13 @@ func (h *StatusHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		BuildInfo:   h.appState.BuildInfo,
 		Flags:       flags,
 	}
-	executeTemplate(w, "status", status)
+
+	// Law of Demeter :-(
+	for state := range h.appState.CurationState {
+		h.PrometheusStatus.Curation = state
+	}
+}
+
+func (h StatusHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	executeTemplate(w, "status", h.PrometheusStatus)
 }

web/templates/status.html

@@ -35,6 +35,30 @@
       </ul>
     </div>
 
+    <h2>Curation</h2>
+    <div class="grouping_box">
+      <table>
+        <tr>
+          <th>Active</th>
+          <td>{{.Curation.Active}}</td>
+        </tr>
+        <tr>
+          <th>Processor Name</th>
+          <td>{{.Curation.Name}}</td>
+        </tr>
+        <tr>
+          <th>Recency Limit</th>
+          <td>{{.Curation.Limit}}</td>
+        </tr>
+        {{if .Curation.Fingerprint}}
+        <tr>
+          <th>Current Fingerprint</th>
+          <td>{{.Curation.Fingerprint}}</td>
+        </tr>
+        {{end}}
+      </table>
+    </div>
+
     <h2>Build Info</h2>
     <div class="grouping_box">
       <table>

web/web.go

@@ -44,7 +44,10 @@ func StartServing(appState *appstate.ApplicationState) {
 	exp.Handle("/debug/pprof/profile", http.HandlerFunc(pprof.Profile))
 	exp.Handle("/debug/pprof/symbol", http.HandlerFunc(pprof.Symbol))
 
-	exp.Handle("/", &StatusHandler{appState: appState})
+	statusHandler := &StatusHandler{appState: appState}
+	go statusHandler.Run()
+
+	exp.Handle("/", statusHandler)
 	exp.HandleFunc("/graph", graphHandler)
 	exp.HandleFunc("/console", consoleHandler)
 
@@ -90,5 +93,8 @@ func executeTemplate(w http.ResponseWriter, name string, data interface{}) {
 		log.Printf("Error preparing layout template: %s", err)
 		return
 	}
-	tpl.Execute(w, data)
+	err = tpl.Execute(w, data)
+	if err != nil {
+		log.Printf("Error executing template: %s", err)
+	}
 }