Merge pull request #3186 from prometheus/startweb

web: start web handler while TSDB is starting up

cmd/prometheus/main.go

@@ -215,35 +215,17 @@ func main() {
 	level.Info(logger).Log("build_context", version.BuildContext())
 	level.Info(logger).Log("host_details", Uname())
 
-	var (
-		// sampleAppender = storage.Fanout{}
-		reloadables []Reloadable
-	)
-
 	// Make sure that sighup handler is registered with a redirect to the channel before the potentially
 	// long and synchronous tsdb init.
 	hup := make(chan os.Signal)
 	hupReady := make(chan bool)
 	signal.Notify(hup, syscall.SIGHUP)
 
-	level.Info(logger).Log("msg", "Starting TSDB")
+	var (
-
+		localStorage  = &tsdb.ReadyStorage{}
-	localStorage, err := tsdb.Open(
+		remoteStorage = remote.NewStorage(log.With(logger, "component", "remote"))
-		cfg.localStoragePath,
+		fanoutStorage = storage.NewFanout(logger, localStorage, remoteStorage)
-		log.With(logger, "component", "tsdb"),
-		prometheus.DefaultRegisterer,
-		&cfg.tsdb,
 	)
-	if err != nil {
-		level.Error(logger).Log("msg", "Opening TSDB failed", "err", err)
-		os.Exit(1)
-	}
-
-	level.Info(logger).Log("msg", "TSDB succesfully started")
-
-	remoteStorage := remote.NewStorage(log.With(logger, "component", "remote"))
-	reloadables = append(reloadables, remoteStorage)
-	fanoutStorage := storage.NewFanout(logger, tsdb.Adapter(localStorage), remoteStorage)
 
 	cfg.queryEngine.Logger = log.With(logger, "component", "query engine")
 	var (
@@ -263,7 +245,8 @@ func main() {
 	})
 
 	cfg.web.Context = ctx
-	cfg.web.Storage = localStorage
+	cfg.web.TSDB = localStorage.Get
+	cfg.web.Storage = fanoutStorage
 	cfg.web.QueryEngine = queryEngine
 	cfg.web.TargetManager = targetManager
 	cfg.web.RuleManager = ruleManager
@@ -285,11 +268,12 @@ func main() {
 
 	webHandler := web.New(log.With(logger, "component", "web"), &cfg.web)
 
-	reloadables = append(reloadables, targetManager, ruleManager, webHandler, notifier)
+	reloadables := []Reloadable{
-
+		remoteStorage,
-	if err := reloadConfig(cfg.configFile, logger, reloadables...); err != nil {
+		targetManager,
-		level.Error(logger).Log("msg", "Error loading config", "err", err)
+		ruleManager,
-		os.Exit(1)
+		webHandler,
+		notifier,
 	}
 
 	// Wait for reload or termination signals. Start the handler for SIGHUP as
@@ -314,14 +298,29 @@ func main() {
 		}
 	}()
 
-	// Start all components. The order is NOT arbitrary.
+	// Start all components while we wait for TSDB to open but only load
-	defer func() {
+	// initial config and mark ourselves as ready after it completed.
-		if err := fanoutStorage.Close(); err != nil {
+	dbOpen := make(chan struct{})
-			level.Error(logger).Log("msg", "Closing storage(s) failed", "err", err)
-		}
-	}()
 
-	// defer remoteStorage.Stop()
+	go func() {
+		defer close(dbOpen)
+
+		level.Info(logger).Log("msg", "Starting TSDB")
+
+		db, err := tsdb.Open(
+			cfg.localStoragePath,
+			log.With(logger, "component", "tsdb"),
+			prometheus.DefaultRegisterer,
+			&cfg.tsdb,
+		)
+		if err != nil {
+			level.Error(logger).Log("msg", "Opening storage failed", "err", err)
+			os.Exit(1)
+		}
+		level.Info(logger).Log("msg", "TSDB started")
+
+		localStorage.Set(db)
+	}()
 
 	prometheus.MustRegister(configSuccess)
 	prometheus.MustRegister(configSuccessTime)
@@ -344,6 +343,19 @@ func main() {
 	errc := make(chan error)
 	go func() { errc <- webHandler.Run(ctx) }()
 
+	<-dbOpen
+
+	if err := reloadConfig(cfg.configFile, logger, reloadables...); err != nil {
+		level.Error(logger).Log("msg", "Error loading config", "err", err)
+		os.Exit(1)
+	}
+
+	defer func() {
+		if err := fanoutStorage.Close(); err != nil {
+			level.Error(logger).Log("msg", "Error stopping storage", "err", err)
+		}
+	}()
+
 	// Wait for reload or termination signals.
 	close(hupReady) // Unblock SIGHUP handler.
 

retrieval/scrape.go

@@ -882,6 +882,7 @@ loop:
 				added++
 				continue
 			default:
+				level.Debug(sl.l).Log("msg", "unexpected error", "series", string(met), "err", err)
 				break loop
 			}
 			if tp == nil {

storage/tsdb/tsdb.go

@@ -14,6 +14,7 @@
 package tsdb
 
 import (
+	"sync"
 	"time"
 	"unsafe"
 
@@ -27,6 +28,63 @@ import (
 	tsdbLabels "github.com/prometheus/tsdb/labels"
 )
 
+// ErrNotReady is returned if the underlying storage is not ready yet.
+var ErrNotReady = errors.New("TSDB not ready")
+
+// ReadyStorage implements the Storage interface while allowing to set the actual
+// storage at a later point in time.
+type ReadyStorage struct {
+	mtx sync.RWMutex
+	a   *adapter
+}
+
+// Set the storage.
+func (s *ReadyStorage) Set(db *tsdb.DB) {
+	s.mtx.Lock()
+	defer s.mtx.Unlock()
+
+	s.a = &adapter{db: db}
+}
+
+// Get the storage.
+func (s *ReadyStorage) Get() *tsdb.DB {
+	if x := s.get(); x != nil {
+		return x.db
+	}
+	return nil
+}
+
+func (s *ReadyStorage) get() *adapter {
+	s.mtx.RLock()
+	x := s.a
+	s.mtx.RUnlock()
+	return x
+}
+
+// Querier implements the Storage interface.
+func (s *ReadyStorage) Querier(mint, maxt int64) (storage.Querier, error) {
+	if x := s.get(); x != nil {
+		return x.Querier(mint, maxt)
+	}
+	return nil, ErrNotReady
+}
+
+// Appender implements the Storage interface.
+func (s *ReadyStorage) Appender() (storage.Appender, error) {
+	if x := s.get(); x != nil {
+		return x.Appender()
+	}
+	return nil, ErrNotReady
+}
+
+// Close implements the Storage interface.
+func (s *ReadyStorage) Close() error {
+	if x := s.Get(); x != nil {
+		return x.Close()
+	}
+	return nil
+}
+
 func Adapter(db *tsdb.DB) storage.Storage {
 	return &adapter{db: db}
 }

web/api/v2/api.go

@@ -46,8 +46,8 @@ import (
 type API struct {
 	enableAdmin   bool
 	now           func() time.Time
-	db            *tsdb.DB
+	db            func() *tsdb.DB
-	q             func(mint, maxt int64) storage.Querier
+	q             func(mint, maxt int64) (storage.Querier, error)
 	targets       func() []*retrieval.Target
 	alertmanagers func() []*url.URL
 }
@@ -55,9 +55,9 @@ type API struct {
 // New returns a new API object.
 func New(
 	now func() time.Time,
-	db *tsdb.DB,
+	db func() *tsdb.DB,
 	qe *promql.Engine,
-	q func(mint, maxt int64) storage.Querier,
+	q func(mint, maxt int64) (storage.Querier, error),
 	targets func() []*retrieval.Target,
 	alertmanagers func() []*url.URL,
 	enableAdmin bool,
@@ -149,28 +149,31 @@ func (s *adminDisabled) DeleteSeries(_ context.Context, r *pb.SeriesDeleteReques
 
 // Admin provides an administration interface to Prometheus.
 type Admin struct {
-	db      *tsdb.DB
+	db func() *tsdb.DB
-	snapdir string
 }
 
 // NewAdmin returns a Admin server.
-func NewAdmin(db *tsdb.DB) *Admin {
+func NewAdmin(db func() *tsdb.DB) *Admin {
 	return &Admin{
-		db:      db,
+		db: db,
-		snapdir: filepath.Join(db.Dir(), "snapshots"),
 	}
 }
 
 // TSDBSnapshot implements pb.AdminServer.
 func (s *Admin) TSDBSnapshot(_ context.Context, _ *pb.TSDBSnapshotRequest) (*pb.TSDBSnapshotResponse, error) {
+	db := s.db()
+	if db == nil {
+		return nil, status.Errorf(codes.Unavailable, "TSDB not ready")
+	}
 	var (
-		name = fmt.Sprintf("%s-%x", time.Now().UTC().Format(time.RFC3339), rand.Int())
+		snapdir = filepath.Join(db.Dir(), "snapshots")
-		dir  = filepath.Join(s.snapdir, name)
+		name    = fmt.Sprintf("%s-%x", time.Now().UTC().Format(time.RFC3339), rand.Int())
+		dir     = filepath.Join(snapdir, name)
 	)
 	if err := os.MkdirAll(dir, 0777); err != nil {
 		return nil, status.Errorf(codes.Internal, "created snapshot directory: %s", err)
 	}
-	if err := s.db.Snapshot(dir); err != nil {
+	if err := db.Snapshot(dir); err != nil {
 		return nil, status.Errorf(codes.Internal, "create snapshot: %s", err)
 	}
 	return &pb.TSDBSnapshotResponse{Name: name}, nil
@@ -210,7 +213,11 @@ func (s *Admin) DeleteSeries(_ context.Context, r *pb.SeriesDeleteRequest) (*pb.
 
 		matchers = append(matchers, lm)
 	}
-	if err := s.db.Delete(timestamp.FromTime(mint), timestamp.FromTime(maxt), matchers...); err != nil {
+	db := s.db()
+	if db == nil {
+		return nil, status.Errorf(codes.Unavailable, "TSDB not ready")
+	}
+	if err := db.Delete(timestamp.FromTime(mint), timestamp.FromTime(maxt), matchers...); err != nil {
 		return nil, status.Error(codes.Internal, err.Error())
 	}
 	return &pb.SeriesDeleteResponse{}, nil

web/web.go

@@ -47,7 +47,6 @@ import (
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/common/route"
 	"github.com/prometheus/prometheus/storage"
-	ptsdb "github.com/prometheus/prometheus/storage/tsdb"
 	"github.com/prometheus/tsdb"
 	"golang.org/x/net/context"
 	"golang.org/x/net/netutil"
@@ -75,7 +74,7 @@ type Handler struct {
 	ruleManager   *rules.Manager
 	queryEngine   *promql.Engine
 	context       context.Context
-	tsdb          *tsdb.DB
+	tsdb          func() *tsdb.DB
 	storage       storage.Storage
 	notifier      *notifier.Notifier
 
@@ -122,7 +121,8 @@ type PrometheusVersion struct {
 // Options for the web Handler.
 type Options struct {
 	Context       context.Context
-	Storage       *tsdb.DB
+	TSDB          func() *tsdb.DB
+	Storage       storage.Storage
 	QueryEngine   *promql.Engine
 	TargetManager *retrieval.TargetManager
 	RuleManager   *rules.Manager
@@ -171,8 +171,8 @@ func New(logger log.Logger, o *Options) *Handler {
 		targetManager: o.TargetManager,
 		ruleManager:   o.RuleManager,
 		queryEngine:   o.QueryEngine,
-		tsdb:          o.Storage,
+		tsdb:          o.TSDB,
-		storage:       ptsdb.Adapter(o.Storage),
+		storage:       o.Storage,
 		notifier:      o.Notifier,
 
 		now: model.Now,
@@ -213,7 +213,7 @@ func New(logger log.Logger, o *Options) *Handler {
 	router.Get("/targets", readyf(instrf("targets", h.targets)))
 	router.Get("/version", readyf(instrf("version", h.version)))
 
-	router.Get("/heap", readyf(instrf("heap", h.dumpHeap)))
+	router.Get("/heap", instrf("heap", h.dumpHeap))
 
 	router.Get("/metrics", prometheus.Handler().ServeHTTP)
 
@@ -223,24 +223,24 @@ func New(logger log.Logger, o *Options) *Handler {
 
 	router.Get("/consoles/*filepath", readyf(instrf("consoles", h.consoles)))
 
-	router.Get("/static/*filepath", readyf(instrf("static", h.serveStaticAsset)))
+	router.Get("/static/*filepath", instrf("static", h.serveStaticAsset))
 
 	if o.UserAssetsPath != "" {
-		router.Get("/user/*filepath", readyf(instrf("user", route.FileServe(o.UserAssetsPath))))
+		router.Get("/user/*filepath", instrf("user", route.FileServe(o.UserAssetsPath)))
 	}
 
 	if o.EnableLifecycle {
 		router.Post("/-/quit", h.quit)
 		router.Post("/-/reload", h.reload)
 	} else {
-		router.Post("/-/quit", readyf(func(w http.ResponseWriter, _ *http.Request) {
+		router.Post("/-/quit", func(w http.ResponseWriter, _ *http.Request) {
 			w.WriteHeader(http.StatusForbidden)
 			w.Write([]byte("Lifecycle APIs are not enabled"))
-		}))
+		})
-		router.Post("/-/reload", readyf(func(w http.ResponseWriter, _ *http.Request) {
+		router.Post("/-/reload", func(w http.ResponseWriter, _ *http.Request) {
 			w.WriteHeader(http.StatusForbidden)
 			w.Write([]byte("Lifecycle APIs are not enabled"))
-		}))
+		})
 	}
 	router.Get("/-/quit", func(w http.ResponseWriter, _ *http.Request) {
 		w.WriteHeader(http.StatusMethodNotAllowed)
@@ -251,8 +251,8 @@ func New(logger log.Logger, o *Options) *Handler {
 		w.Write([]byte("Only POST requests allowed"))
 	})
 
-	router.Get("/debug/*subpath", readyf(serveDebug))
+	router.Get("/debug/*subpath", serveDebug)
-	router.Post("/debug/*subpath", readyf(serveDebug))
+	router.Post("/debug/*subpath", serveDebug)
 
 	router.Get("/-/healthy", func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)
@@ -380,15 +380,9 @@ func (h *Handler) Run(ctx context.Context) error {
 	)
 	av2 := api_v2.New(
 		time.Now,
-		h.options.Storage,
+		h.options.TSDB,
 		h.options.QueryEngine,
-		func(mint, maxt int64) storage.Querier {
+		h.options.Storage.Querier,
-			q, err := ptsdb.Adapter(h.options.Storage).Querier(mint, maxt)
-			if err != nil {
-				panic(err)
-			}
-			return q
-		},
 		func() []*retrieval.Target {
 			return h.options.TargetManager.Targets()
 		},

web/web_test.go

@@ -19,6 +19,8 @@ import (
 	"net/url"
 	"testing"
 	"time"
+
+	"github.com/prometheus/prometheus/storage/tsdb"
 )
 
 func TestGlobalURL(t *testing.T) {
@@ -78,7 +80,7 @@ func TestReadyAndHealthy(t *testing.T) {
 		ReadTimeout:    30 * time.Second,
 		MaxConnections: 512,
 		Context:        nil,
-		Storage:        nil,
+		Storage:        &tsdb.ReadyStorage{},
 		QueryEngine:    nil,
 		TargetManager:  nil,
 		RuleManager:    nil,
@@ -155,7 +157,7 @@ func TestRoutePrefix(t *testing.T) {
 		ReadTimeout:    30 * time.Second,
 		MaxConnections: 512,
 		Context:        nil,
-		Storage:        nil,
+		Storage:        &tsdb.ReadyStorage{},
 		QueryEngine:    nil,
 		TargetManager:  nil,
 		RuleManager:    nil,