refactor(backend): refactoring management of go routines in backend

pkg/cmd/grafana-server/main.go

@@ -19,14 +19,20 @@ import (
 	"github.com/grafana/grafana/pkg/login"
 	"github.com/grafana/grafana/pkg/metrics"
 	"github.com/grafana/grafana/pkg/plugins"
-	alertingInit "github.com/grafana/grafana/pkg/services/alerting/init"
-	"github.com/grafana/grafana/pkg/services/backgroundtasks"
+	"github.com/grafana/grafana/pkg/services/cleanup"
 	"github.com/grafana/grafana/pkg/services/eventpublisher"
 	"github.com/grafana/grafana/pkg/services/notifications"
 	"github.com/grafana/grafana/pkg/services/search"
 	"github.com/grafana/grafana/pkg/services/sqlstore"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/social"
+
+	"github.com/grafana/grafana/pkg/services/alerting"
+	_ "github.com/grafana/grafana/pkg/services/alerting/conditions"
+	_ "github.com/grafana/grafana/pkg/services/alerting/notifiers"
+	_ "github.com/grafana/grafana/pkg/tsdb/graphite"
+	_ "github.com/grafana/grafana/pkg/tsdb/prometheus"
+	_ "github.com/grafana/grafana/pkg/tsdb/testdata"
 )
 
 var version = "3.1.0"
@@ -67,6 +73,7 @@ func main() {
 
 	flag.Parse()
 	writePIDFile()
+
 	initRuntime()
 	initSql()
 	metrics.Init()
@@ -76,8 +83,15 @@ func main() {
 	eventpublisher.Init()
 	plugins.Init()
 
-	grafanaGroup.Go(func() error { return alertingInit.Init(appContext) })
-	grafanaGroup.Go(func() error { return backgroundtasks.Init(appContext) })
+	// init alerting
+	if setting.AlertingEnabled {
+		engine := alerting.NewEngine()
+		grafanaGroup.Go(func() error { return engine.Run(appContext) })
+	}
+
+	// cleanup service
+	cleanUpService := cleanup.NewCleanUpService()
+	grafanaGroup.Go(func() error { return cleanUpService.Run(appContext) })
 
 	if err := notifications.Init(); err != nil {
 		log.Fatal(3, "Notification service failed to initialize", err)

pkg/models/dashboard_snapshot.go

@@ -63,6 +63,9 @@ type DeleteDashboardSnapshotCommand struct {
 	DeleteKey string `json:"-"`
 }
 
+type DeleteExpiredSnapshotsCommand struct {
+}
+
 type GetDashboardSnapshotQuery struct {
 	Key string
 

pkg/models/timer.go

@@ -1,7 +0,0 @@
-package models
-
-import "time"
-
-type HourCommand struct {
-	Time time.Time
-}

pkg/services/alerting/engine.go

@@ -36,16 +36,19 @@ func NewEngine() *Engine {
 	return e
 }
 
-func (e *Engine) Start(grafanaCtx context.Context) error {
-	e.log.Info("Starting Alerting Engine")
+func (e *Engine) Run(ctx context.Context) error {
+	e.log.Info("Initializing Alerting")
 
-	g, grafanaCtx := errgroup.WithContext(grafanaCtx)
+	g, ctx := errgroup.WithContext(ctx)
 
-	g.Go(func() error { return e.alertingTicker(grafanaCtx) })
-	g.Go(func() error { return e.execDispatcher(grafanaCtx) })
-	g.Go(func() error { return e.resultDispatcher(grafanaCtx) })
+	g.Go(func() error { return e.alertingTicker(ctx) })
+	g.Go(func() error { return e.execDispatcher(ctx) })
+	g.Go(func() error { return e.resultDispatcher(ctx) })
 
-	return g.Wait()
+	err := g.Wait()
+
+	e.log.Info("Stopped Alerting", "reason", err)
+	return err
 }
 
 func (e *Engine) Stop() {

pkg/services/alerting/init/init.go

@@ -12,8 +12,6 @@ import (
 	_ "github.com/grafana/grafana/pkg/tsdb/testdata"
 )
 
-var engine *alerting.Engine
-
 func Init(ctx context.Context) error {
 	if !setting.AlertingEnabled {
 		return nil

pkg/services/backgroundtasks/background_tasks.go

@@ -1,47 +0,0 @@
-//"I want to be a cleaner, just like you," said Mathilda
-//"Okay," replied Leon
-
-package backgroundtasks
-
-import (
-	"context"
-	"time"
-
-	"golang.org/x/sync/errgroup"
-
-	"github.com/grafana/grafana/pkg/bus"
-	"github.com/grafana/grafana/pkg/log"
-	"github.com/grafana/grafana/pkg/models"
-)
-
-var (
-	tlog log.Logger = log.New("ticker")
-)
-
-func Init(ctx context.Context) error {
-	g, _ := errgroup.WithContext(ctx)
-	g.Go(func() error { return start(ctx) })
-
-	return g.Wait()
-}
-
-func start(ctx context.Context) error {
-	go cleanup(time.Now())
-
-	ticker := time.NewTicker(time.Hour * 1)
-	for {
-		select {
-		case tick := <-ticker.C:
-			go cleanup(tick)
-		case <-ctx.Done():
-			return ctx.Err()
-		}
-	}
-}
-
-func cleanup(now time.Time) {
-	err := bus.Publish(&models.HourCommand{Time: now})
-	if err != nil {
-		tlog.Error("Cleanup job failed", "error", err)
-	}
-}

pkg/services/backgroundtasks/remove_tmp_images.go

@@ -1,38 +0,0 @@
-package backgroundtasks
-
-import (
-	"io/ioutil"
-	"os"
-	"path"
-
-	"github.com/grafana/grafana/pkg/bus"
-	"github.com/grafana/grafana/pkg/models"
-	"github.com/grafana/grafana/pkg/setting"
-)
-
-func init() {
-	bus.AddEventListener(CleanTmpFiles)
-}
-
-func CleanTmpFiles(cmd *models.HourCommand) error {
-	files, err := ioutil.ReadDir(setting.ImagesDir)
-
-	var toDelete []os.FileInfo
-	for _, file := range files {
-		if file.ModTime().AddDate(0, 0, setting.RenderedImageTTLDays).Before(cmd.Time) {
-			toDelete = append(toDelete, file)
-		}
-	}
-
-	for _, file := range toDelete {
-		fullPath := path.Join(setting.ImagesDir, file.Name())
-		err := os.Remove(fullPath)
-		if err != nil {
-			return err
-		}
-	}
-
-	tlog.Debug("Found old rendered image to delete", "deleted", len(toDelete), "keept", len(files))
-
-	return err
-}

pkg/services/cleanup/cleanup.go

@@ -0,0 +1,81 @@
+package cleanup
+
+import (
+	"context"
+	"io/ioutil"
+	"os"
+	"path"
+	"time"
+
+	"golang.org/x/sync/errgroup"
+
+	"github.com/grafana/grafana/pkg/bus"
+	"github.com/grafana/grafana/pkg/log"
+	m "github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/setting"
+)
+
+type CleanUpService struct {
+	log log.Logger
+}
+
+func NewCleanUpService() *CleanUpService {
+	return &CleanUpService{
+		log: log.New("cleanup"),
+	}
+}
+
+func (service *CleanUpService) Run(ctx context.Context) error {
+	service.log.Info("Initializing CleanUpService")
+
+	g, _ := errgroup.WithContext(ctx)
+	g.Go(func() error { return service.start(ctx) })
+
+	err := g.Wait()
+	service.log.Info("Stopped CleanUpService", "reason", err)
+	return err
+}
+
+func (service *CleanUpService) start(ctx context.Context) error {
+	service.cleanUpTmpFiles()
+
+	ticker := time.NewTicker(time.Hour * 1)
+	for {
+		select {
+		case <-ticker.C:
+			service.cleanUpTmpFiles()
+			service.deleteExpiredSnapshots()
+		case <-ctx.Done():
+			return ctx.Err()
+		}
+	}
+}
+
+func (service *CleanUpService) cleanUpTmpFiles() {
+	files, err := ioutil.ReadDir(setting.ImagesDir)
+	if err != nil {
+		service.log.Error("Problem reading image dir", "error", err)
+		return
+	}
+
+	var toDelete []os.FileInfo
+	for _, file := range files {
+		if file.ModTime().AddDate(0, 0, 1).Before(time.Now()) {
+			toDelete = append(toDelete, file)
+		}
+	}
+
+	for _, file := range toDelete {
+		fullPath := path.Join(setting.ImagesDir, file.Name())
+		err := os.Remove(fullPath)
+		if err != nil {
+			service.log.Error("Failed to delete temp file", "file", file.Name(), "error", err)
+		}
+	}
+
+	service.log.Debug("Found old rendered image to delete", "deleted", len(toDelete), "keept", len(files))
+}
+
+func (service *CleanUpService) deleteExpiredSnapshots() {
+	bus.Dispatch(&m.DeleteExpiredSnapshotsCommand{})
+}

pkg/services/sqlstore/dashboard_snapshot.go

@@ -5,7 +5,6 @@ import (
 
 	"github.com/go-xorm/xorm"
 	"github.com/grafana/grafana/pkg/bus"
-	"github.com/grafana/grafana/pkg/log"
 	m "github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/setting"
 )
@@ -15,30 +14,24 @@ func init() {
 	bus.AddHandler("sql", GetDashboardSnapshot)
 	bus.AddHandler("sql", DeleteDashboardSnapshot)
 	bus.AddHandler("sql", SearchDashboardSnapshots)
-	bus.AddEventListener(DeleteExpiredSnapshots)
+	bus.AddHandler("sql", DeleteExpiredSnapshots)
 }
 
-func DeleteExpiredSnapshots(cmd *m.HourCommand) error {
+func DeleteExpiredSnapshots(cmd *m.DeleteExpiredSnapshotsCommand) error {
 	return inTransaction(func(sess *xorm.Session) error {
 		var expiredCount int64 = 0
-		var oldCount int64 = 0
 
 		if setting.SnapShotRemoveExpired {
 			deleteExpiredSql := "DELETE FROM dashboard_snapshot WHERE expires < ?"
-			expiredResponse, err := x.Exec(deleteExpiredSql, cmd.Time)
+			expiredResponse, err := x.Exec(deleteExpiredSql, time.Now)
 			if err != nil {
 				return err
 			}
 			expiredCount, _ = expiredResponse.RowsAffected()
 		}
 
-		oldSnapshotsSql := "DELETE FROM dashboard_snapshot WHERE created < ?"
-		oldResponse, err := x.Exec(oldSnapshotsSql, cmd.Time.AddDate(0, 0, setting.SnapShotTTLDays*-1))
-		oldCount, _ = oldResponse.RowsAffected()
-
-		log.Debug2("Deleted old/expired snaphots", "to old", oldCount, "expired", expiredCount)
-
-		return err
+		sqlog.Debug("Deleted old/expired snaphots", "expired", expiredCount)
+		return nil
 	})
 }
 

pkg/setting/setting.go

@@ -120,9 +120,8 @@ var (
 	IsWindows    bool
 
 	// PhantomJs Rendering
-	ImagesDir            string
-	PhantomDir           string
-	RenderedImageTTLDays int
+	ImagesDir  string
+	PhantomDir string
 
 	// for logging purposes
 	configFiles                  []string
@@ -540,9 +539,6 @@ func NewConfigContext(args *CommandLineArgs) error {
 	ImagesDir = filepath.Join(DataPath, "png")
 	PhantomDir = filepath.Join(HomePath, "vendor/phantomjs")
 
-	tmpFilesSection := Cfg.Section("tmp.files")
-	RenderedImageTTLDays = tmpFilesSection.Key("rendered_image_ttl_days").MustInt(14)
-
 	analytics := Cfg.Section("analytics")
 	ReportingEnabled = analytics.Key("reporting_enabled").MustBool(true)
 	CheckForUpdates = analytics.Key("check_for_updates").MustBool(true)