Merge pull request #1 from xtrimf/support_for_triggers

Support for triggers

Author: eldadts

go/base/context.go

@@ -21,7 +21,6 @@ import (
 	"github.com/github/gh-ost/go/mysql"
 	"github.com/github/gh-ost/go/sql"
 	"github.com/openark/golib/log"
-	"github.com/openark/golib/sqlutils"
 
 	"github.com/go-ini/ini"
 )
@@ -229,7 +228,7 @@ type MigrationContext struct {
 	IncludeTriggers     bool
 	RemoveTriggerSuffix bool
 	TriggerSuffix       string
-	Triggers            []*sqlutils.RowMap
+	Triggers            []mysql.Trigger
 
 	recentBinlogCoordinates mysql.BinlogCoordinates
 
@@ -864,22 +863,21 @@ func (this *MigrationContext) ReadConfigFile() error {
 // getGhostTriggerName generates the name of a ghost trigger, based on original trigger name
 // or a given trigger name
 func (this *MigrationContext) GetGhostTriggerName(triggerName string) string {
-	// var triggerName string
-	if this.RemoveTriggerSuffix && strings.HasSuffix(triggerName, this.TriggerSuffix) {
+	if this.RemoveTriggerSuffix {
 		return strings.TrimSuffix(triggerName, this.TriggerSuffix)
 	}
 
 	return triggerName + this.TriggerSuffix
 }
 
 // validateGhostTriggerLength check if the ghost trigger name length is not more than 64 characters
-func (this *MigrationContext) ValidateGhostTriggerLengthBelow65chars(triggerName string) bool {
+func (this *MigrationContext) ValidateGhostTriggerLengthBelowMaxLength(triggerName string) bool {
 	var ghostTriggerName string
-	if this.RemoveTriggerSuffix && strings.HasSuffix(triggerName, this.TriggerSuffix) {
+	if this.RemoveTriggerSuffix {
 		ghostTriggerName = strings.TrimSuffix(triggerName, this.TriggerSuffix)
 	} else {
 		ghostTriggerName = triggerName + this.TriggerSuffix
 	}
 
-	return utf8.RuneCountInString(ghostTriggerName) < 65
+	return utf8.RuneCountInString(ghostTriggerName) <= mysql.MaxTableNameLength
 }

go/base/context_test.go

@@ -87,39 +87,39 @@ func TestGetTriggerNames(t *testing.T) {
 	}
 
 }
-func TestValidateGhostTriggerLengthBelow65chars(t *testing.T) {
+func TestValidateGhostTriggerLengthBelowMaxLength(t *testing.T) {
 	{
 		context := NewMigrationContext()
 		context.TriggerSuffix = "_gho"
-		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelow65chars("my_trigger"), true)
+		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelowMaxLength("my_trigger"), true)
 	}
 	{
 		context := NewMigrationContext()
 		context.TriggerSuffix = "_ghost"
-		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelow65chars(strings.Repeat("my_trigger_ghost", 4)), false) // 64 characters + "_ghost"
+		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelowMaxLength(strings.Repeat("my_trigger_ghost", 4)), false) // 64 characters + "_ghost"
 	}
 	{
 		context := NewMigrationContext()
 		context.TriggerSuffix = "_ghost"
-		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelow65chars(strings.Repeat("my_trigger_ghost", 3)), true) // 48 characters + "_ghost"
+		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelowMaxLength(strings.Repeat("my_trigger_ghost", 3)), true) // 48 characters + "_ghost"
 	}
 	{
 		context := NewMigrationContext()
 		context.TriggerSuffix = "_ghost"
 		context.RemoveTriggerSuffix = true
-		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelow65chars(strings.Repeat("my_trigger_ghost", 4)), true) // 64 characters + "_ghost" removed
+		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelowMaxLength(strings.Repeat("my_trigger_ghost", 4)), true) // 64 characters + "_ghost" removed
 	}
 	{
 		context := NewMigrationContext()
 		context.TriggerSuffix = "_ghost"
 		context.RemoveTriggerSuffix = true
-		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelow65chars(strings.Repeat("my_trigger_ghost", 4)+"X"), false) // 65 characters + "_ghost" not removed
+		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelowMaxLength(strings.Repeat("my_trigger_ghost", 4)+"X"), false) // 65 characters + "_ghost" not removed
 	}
 	{
 		context := NewMigrationContext()
 		context.TriggerSuffix = "_ghost"
 		context.RemoveTriggerSuffix = true
-		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelow65chars(strings.Repeat("my_trigger_ghost", 4)+"_ghost"), true) // 70 characters + last "_ghost"  removed
+		test.S(t).ExpectEquals(context.ValidateGhostTriggerLengthBelowMaxLength(strings.Repeat("my_trigger_ghost", 4)+"_ghost"), true) // 70 characters + last "_ghost"  removed
 	}
 }
 

go/cmd/gh-ost/main.go

@@ -129,8 +129,8 @@ func main() {
 	flag.UintVar(&migrationContext.ReplicaServerId, "replica-server-id", 99999, "server id used by gh-ost process. Default: 99999")
 
 	flag.BoolVar(&migrationContext.IncludeTriggers, "include-triggers", false, "When true, the triggers (if exist) will be created on the new table")
-	flag.StringVar(&migrationContext.TriggerSuffix, "trigger-suffix", "", "have to be used with '--include-triggers'")
-	flag.BoolVar(&migrationContext.RemoveTriggerSuffix, "remove-trigger-suffix-if-exists", false, "Removal (instead of addition) of trigger suffix if it exists at the end of the original triger name. Have to be used with '--include-triggers' and '--TriggerSuffix'")
+	flag.StringVar(&migrationContext.TriggerSuffix, "trigger-suffix", "", "Add a suffix to the trigger name (i.e '_v2'). Requires '--include-triggers'")
+	flag.BoolVar(&migrationContext.RemoveTriggerSuffix, "remove-trigger-suffix-if-exists", false, "Remove given suffix from name of trigger. Requires '--include-triggers' and '--trigger-suffix'")
 
 	maxLoad := flag.String("max-load", "", "Comma delimited status-name=threshold. e.g: 'Threads_running=100,Threads_connected=500'. When status exceeds threshold, app throttles writes")
 	criticalLoad := flag.String("critical-load", "", "Comma delimited status-name=threshold, same format as --max-load. When status exceeds threshold, app panics and quits")
@@ -247,9 +247,9 @@ func main() {
 		migrationContext.Log.Fatalf("--trigger-suffix cannot be be used without --include-triggers")
 	}
 	if migrationContext.TriggerSuffix != "" {
-		regex, err := regexp.Compile(`^[\da-zA-Z_]+$`)
+		regex := regexp.MustCompile(`^[\da-zA-Z_]+$`)
 
-		if err != nil || !regex.Match([]byte(migrationContext.TriggerSuffix)) {
+		if !regex.Match([]byte(migrationContext.TriggerSuffix)) {
 			migrationContext.Log.Fatalf("--trigger-suffix must contain only alpha numeric characters and underscore (0-9,a-z,A-Z,_)")
 		}
 	}

go/logic/applier.go

@@ -276,7 +276,7 @@ func (this *Applier) dropTable(tableName string) error {
 func (this *Applier) DropTriggersFromGhost() error {
 	if len(this.migrationContext.Triggers) > 0 {
 		for _, trigger := range this.migrationContext.Triggers {
-			triggerName := this.migrationContext.GetGhostTriggerName((*trigger).GetString("name"))
+			triggerName := this.migrationContext.GetGhostTriggerName(trigger.Name)
 			query := fmt.Sprintf("drop trigger if exists %s", sql.EscapeName(triggerName))
 			_, err := sqlutils.ExecNoPrepare(this.db, query)
 			if err != nil {
@@ -292,15 +292,15 @@ func (this *Applier) DropTriggersFromGhost() error {
 func (this *Applier) createTriggers(tableName string) error {
 	if len(this.migrationContext.Triggers) > 0 {
 		for _, trigger := range this.migrationContext.Triggers {
-			triggerName := this.migrationContext.GetGhostTriggerName((*trigger).GetString("name"))
+			triggerName := this.migrationContext.GetGhostTriggerName(trigger.Name)
 			query := fmt.Sprintf(`create /* gh-ost */ trigger %s %s %s on %s.%s for each row
 		%s`,
 				sql.EscapeName(triggerName),
-				(*trigger).GetString("timing"),
-				(*trigger).GetString("event"),
+				trigger.Timing,
+				trigger.Event,
 				sql.EscapeName(this.migrationContext.DatabaseName),
 				sql.EscapeName(tableName),
-				(*trigger).GetString("statement"),
+				trigger.Statement,
 			)
 			this.migrationContext.Log.Infof("Createing trigger %s on %s.%s",
 				sql.EscapeName(triggerName),
@@ -316,14 +316,7 @@ func (this *Applier) createTriggers(tableName string) error {
 	return nil
 }
 
-// ReCreateTriggers creates the original triggers on applier host
-func (this *Applier) CreateTriggersOnGhostAtomic(tableLocked chan<- error) error {
-	err := this.createTriggers(this.migrationContext.GetGhostTableName())
-	tableLocked <- err
-	return err
-}
-
-// ReCreateTriggers creates the original triggers on applier host
+// CreateTriggers creates the original triggers on applier host
 func (this *Applier) CreateTriggersOnGhost() error {
 	err := this.createTriggers(this.migrationContext.GetGhostTableName())
 	return err

go/logic/inspect.go

@@ -531,7 +531,7 @@ func (this *Inspector) validateGhostTriggersDontExist() error {
 	if len(this.migrationContext.Triggers) > 0 {
 		var foundTriggers []string
 		for _, trigger := range this.migrationContext.Triggers {
-			triggerName := this.migrationContext.GetGhostTriggerName((*trigger).GetString("name"))
+			triggerName := this.migrationContext.GetGhostTriggerName(trigger.Name)
 			query := "select 1 from information_schema.triggers where trigger_name = ? and trigger_schema = ?"
 			err := sqlutils.QueryRowsMap(this.db, query, func(rowMap sqlutils.RowMap) error {
 				triggerExists := rowMap.GetInt("1")
@@ -559,14 +559,14 @@ func (this *Inspector) validateGhostTriggersLength() error {
 	if len(this.migrationContext.Triggers) > 0 {
 		var foundTriggers []string
 		for _, trigger := range this.migrationContext.Triggers {
-			triggerName := this.migrationContext.GetGhostTriggerName((*trigger).GetString("name"))
-			if ok := this.migrationContext.ValidateGhostTriggerLengthBelow65chars(triggerName); !ok {
+			triggerName := this.migrationContext.GetGhostTriggerName(trigger.Name)
+			if ok := this.migrationContext.ValidateGhostTriggerLengthBelowMaxLength(triggerName); !ok {
 				foundTriggers = append(foundTriggers, triggerName)
 			}
 
 		}
 		if len(foundTriggers) > 0 {
-			return this.migrationContext.Log.Errorf("Gh-ost triggers (%s) length > 64 characters. Bailing out", strings.Join(foundTriggers, ","))
+			return this.migrationContext.Log.Errorf("Gh-ost triggers (%s) length > %d characters. Bailing out", strings.Join(foundTriggers, ","),mysql.MaxTableNameLength)
 		}
 	}
 

go/logic/migrator.go

@@ -671,14 +671,8 @@ func (this *Migrator) atomicCutOver() (err error) {
 
 	// If we need to create triggers we need to do it here (only create part)
 	if this.migrationContext.IncludeTriggers && len(this.migrationContext.Triggers) > 0 {
-		triggersCreated := make(chan error, 2)
-		go func() {
-			if err := this.applier.CreateTriggersOnGhostAtomic(triggersCreated); err != nil {
-				this.migrationContext.Log.Errore(err)
-			}
-		}()
-		if err := <-triggersCreated; err != nil {
-			return this.migrationContext.Log.Errore(err)
+		if err := this.applier.CreateTriggersOnGhost(); err != nil {
+			this.migrationContext.Log.Errore(err)
 		}
 	}
 

go/mysql/utils.go

@@ -30,6 +30,13 @@ type ReplicationLagResult struct {
 	Err error
 }
 
+type Trigger struct {
+	Name      string
+	Event     string
+	Statement string
+	Timing    string
+}
+
 func NewNoReplicationLagResult() *ReplicationLagResult {
 	return &ReplicationLagResult{Lag: 0, Err: nil}
 }
@@ -207,13 +214,18 @@ func GetTableColumns(db *gosql.DB, databaseName, tableName string) (*sql.ColumnL
 }
 
 // GetTriggers reads trigger list from given table
-func GetTriggers(db *gosql.DB, databaseName, tableName string) (triggers []*sqlutils.RowMap, err error) {
+func GetTriggers(db *gosql.DB, databaseName, tableName string) (triggers []Trigger, err error) {
 	query := fmt.Sprintf(`select trigger_name as name, event_manipulation as event, action_statement as statement, action_timing as timing
 	from information_schema.triggers 
 	where trigger_schema = '%s' and event_object_table = '%s'`, databaseName, tableName)
-	
+
 	err = sqlutils.QueryRowsMap(db, query, func(rowMap sqlutils.RowMap) error {
-		triggers = append(triggers, &rowMap)
+		triggers = append(triggers, Trigger{
+			Name:      rowMap.GetString("name"),
+			Event:     rowMap.GetString("event"),
+			Statement: rowMap.GetString("statement"),
+			Timing:    rowMap.GetString("timing"),
+		})
 		return nil
 	})
 	if err != nil {