Merge pull request #46 from github/operational-perks

operational perks

Author: Shlomi Noach

build.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 #
 #
-RELEASE_VERSION="0.7.17"
+RELEASE_VERSION="0.8.2"
 
 buildpath=/tmp/gh-ost
 target=gh-ost

go/cmd/gh-ost/main.go

@@ -9,6 +9,8 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"os/signal"
+	"syscall"
 
 	"github.com/github/gh-ost/go/base"
 	"github.com/github/gh-ost/go/logic"
@@ -17,6 +19,26 @@ import (
 
 var AppVersion string
 
+// acceptSignals registers for OS signals
+func acceptSignals(migrationContext *base.MigrationContext) {
+	c := make(chan os.Signal, 1)
+
+	signal.Notify(c, syscall.SIGHUP)
+	go func() {
+		for sig := range c {
+			switch sig {
+			case syscall.SIGHUP:
+				log.Infof("Received SIGHUP. Reloading configuration")
+				if err := migrationContext.ReadConfigFile(); err != nil {
+					log.Errore(err)
+				} else {
+					migrationContext.MarkPointOfInterest()
+				}
+			}
+		}
+	}()
+}
+
 // main is the application's entry point. It will either spawn a CLI or HTTP itnerfaces.
 func main() {
 	migrationContext := base.GetMigrationContext()
@@ -122,6 +144,7 @@ func main() {
 	migrationContext.ApplyCredentials()
 
 	log.Infof("starting gh-ost %+v", AppVersion)
+	acceptSignals(migrationContext)
 
 	migrator := logic.NewMigrator()
 	err := migrator.Migrate()

go/logic/migrator.go

@@ -578,8 +578,21 @@ func (this *Migrator) printStatus() {
 	if rowsEstimate > 0 {
 		progressPct = 100.0 * float64(totalRowsCopied) / float64(rowsEstimate)
 	}
-	var etaSeconds float64 = math.MaxFloat64
 
+	// Before status, let's see if we should print a nice reminder for what exactly we're doing here.
+	shouldPrintCourtesyReminder := (elapsedSeconds%600 == 0)
+	if shouldPrintCourtesyReminder {
+		courtesyReminder := fmt.Sprintf("# Migrating %s.%s; Ghost table is %s.%s; migration started at %+v",
+			sql.EscapeName(this.migrationContext.DatabaseName),
+			sql.EscapeName(this.migrationContext.OriginalTableName),
+			sql.EscapeName(this.migrationContext.DatabaseName),
+			sql.EscapeName(this.migrationContext.GetGhostTableName()),
+			this.migrationContext.StartTime.Format(time.RubyDate),
+		)
+		fmt.Println(courtesyReminder)
+	}
+
+	var etaSeconds float64 = math.MaxFloat64
 	eta := "N/A"
 	if isThrottled, throttleReason := this.migrationContext.IsThrottled(); isThrottled {
 		eta = fmt.Sprintf("throttled, %s", throttleReason)
@@ -606,7 +619,7 @@ func (this *Migrator) printStatus() {
 		shouldPrintStatus = (elapsedSeconds%5 == 0)
 	} else if elapsedSeconds <= 180 {
 		shouldPrintStatus = (elapsedSeconds%5 == 0)
-	} else if this.migrationContext.TimeSincePointOfInterest() <= 60 {
+	} else if this.migrationContext.TimeSincePointOfInterest().Seconds() <= 60 {
 		shouldPrintStatus = (elapsedSeconds%5 == 0)
 	} else {
 		shouldPrintStatus = (elapsedSeconds%30 == 0)

go/logic/streamer.go

@@ -189,6 +189,7 @@ func (this *EventsStreamer) StreamEvents(canStopStreaming func() bool) error {
 	for {
 		if err := this.binlogReader.StreamEvents(canStopStreaming, this.eventsChannel); err != nil {
 			log.Infof("StreamEvents encountered unexpected error: %+v", err)
+			this.migrationContext.MarkPointOfInterest()
 			time.Sleep(ReconnectStreamerSleepSeconds * time.Second)
 
 			// Reposition at same binlog file. Single attempt (TODO: make multiple attempts?)