Adding pprof flag to support better tracing & rewriting file watching

cfg/config.go

@@ -118,6 +118,7 @@ var SaveSnapshotFlag = flag.Bool("save-snapshot", false, "Only take snapshot and
 var ClusterAddrFlag = flag.String("cluster-addr", "", "Cluster listening address")
 var ClusterPeersFlag = flag.String("cluster-peers", "", "Comma separated list of clusters")
 var LeafServerFlag = flag.String("leaf-servers", "", "Comma separated list of leaf servers")
+var ProfServer = flag.String("pprof", "", "PProf listening address")
 
 var DataRootDir = os.TempDir()
 var Config = &Configuration{

db/change_log.go

@@ -253,34 +253,54 @@ func (conn *SqliteStreamDB) initTriggers(tableName string) error {
 	return nil
 }
 
+func (conn *SqliteStreamDB) filterChangesTo(changed chan fsnotify.Event, watcher *fsnotify.Watcher) {
+	for {
+		select {
+		case ev, ok := <-watcher.Events:
+			if !ok {
+				close(changed)
+				return
+			}
+
+			if ev.Op == fsnotify.Chmod {
+				continue
+			}
+
+			changed <- ev
+		}
+	}
+}
+
 func (conn *SqliteStreamDB) watchChanges(watcher *fsnotify.Watcher, path string) {
 	shmPath := path + "-shm"
 	walPath := path + "-wal"
 
 	errDB := watcher.Add(path)
 	errShm := watcher.Add(shmPath)
 	errWal := watcher.Add(walPath)
+	dbChanged := make(chan fsnotify.Event)
 
 	tickerDur := time.Duration(cfg.Config.PollingInterval) * time.Millisecond
 	changeLogTicker := utils.NewTimeoutPublisher(tickerDur)
 
 	// Publish change logs for any residual change logs before starting watcher
 	conn.publishChangeLog()
+	go conn.filterChangesTo(dbChanged, watcher)
 
 	for {
 		changeLogTicker.Reset()
 
 		err := conn.WithReadTx(func(_tx *sql.Tx) error {
 			select {
-			case ev, ok := <-watcher.Events:
+			case ev, ok := <-dbChanged:
 				if !ok {
 					return ErrEndOfWatch
 				}
 
-				if ev.Op != fsnotify.Chmod {
-					conn.publishChangeLog()
-				}
+				log.Debug().Int("change", int(ev.Op)).Msg("Change detected")
+				conn.publishChangeLog()
 			case <-changeLogTicker.Channel():
+				log.Debug().Dur("timeout", tickerDur).Msg("Change polling timeout")
 				conn.publishChangeLog()
 			}
 

marmot.go

@@ -4,6 +4,9 @@ import (
 	"context"
 	"flag"
 	"io"
+	"net/http"
+	"net/http/pprof"
+	_ "net/http/pprof"
 	"os"
 	"time"
 
@@ -22,7 +25,6 @@ import (
 
 func main() {
 	flag.Parse()
-
 	err := cfg.Load(*cfg.ConfigPathFlag)
 	if err != nil {
 		panic(err)
@@ -44,6 +46,22 @@ func main() {
 		log.Logger = gLog.Level(zerolog.InfoLevel)
 	}
 
+	if *cfg.ProfServer != "" {
+		go func() {
+			mux := http.NewServeMux()
+			mux.HandleFunc("/debug/pprof/", pprof.Index)
+			mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
+			mux.HandleFunc("/debug/pprof/profile", pprof.Profile)
+			mux.HandleFunc("/debug/pprof/symbol", pprof.Symbol)
+			mux.HandleFunc("/debug/pprof/trace", pprof.Trace)
+
+			err := http.ListenAndServe(*cfg.ProfServer, mux)
+			if err != nil {
+				log.Error().Err(err).Msg("unable to bind profiler server")
+			}
+		}()
+	}
+
 	log.Debug().Msg("Initializing telemetry")
 	telemetry.InitializeTelemetry()