From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
Subject: [PATCH] daed: reload dae outside the database transaction
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配置生效前先提交读事务，reload 完再用短事务写运行状态。

原来整个 reload 都在事务里，最长可占着数据库锁一百多秒；写状态时按 ID 重查仍存在的分组，避免把 reload 期间被删的分组重新插回去。
---
 graphql/service/config/mutation_utils.go | 77 ++++++++++++++++--------
 1 file changed, 53 insertions(+), 24 deletions(-)

diff --git a/graphql/service/config/mutation_utils.go b/graphql/service/config/mutation_utils.go
index feb94d3..59f0ebd 100644
--- a/graphql/service/config/mutation_utils.go
+++ b/graphql/service/config/mutation_utils.go
@@ -270,28 +270,12 @@ func restartAfterReloadTimeout() {
 	}()
 }
 
-func runTransaction(ctx context.Context, noLoad bool) (n int32, err error) {
-	tx := db.BeginTx(ctx)
-	if tx.Error != nil {
-		return 0, tx.Error
-	}
-	n, err = runLocked(tx, noLoad)
-	if err != nil {
-		tx.Rollback()
-		return 0, err
-	}
-	if err = tx.Commit().Error; err != nil {
-		return 0, err
-	}
-	return n, nil
-}
-
 func Run(ctx context.Context, noLoad bool) (n int32, err error) {
 	if ok := runLock.TryLock(); !ok {
 		return 0, fmt.Errorf("the last request didn't complete; make a cup of tea and take a break")
 	}
 	defer runLock.Unlock()
-	return runTransaction(ctx, noLoad)
+	return runLocked(ctx, noLoad)
 }
 
 func ApplyIfRunning(ctx context.Context) error {
@@ -307,11 +291,11 @@ func ApplyIfRunning(ctx context.Context) error {
 	if err != nil || !modified {
 		return err
 	}
-	_, err = runTransaction(ctx, false)
+	_, err = runLocked(ctx, false)
 	return err
 }
 
-func runLocked(d *gorm.DB, noLoad bool) (n int32, err error) {
+func runLocked(ctx context.Context, noLoad bool) (n int32, err error) {
 	//// Dry run.
 	if noLoad {
 		ch := make(chan error)
@@ -336,18 +320,38 @@ func runLocked(d *gorm.DB, noLoad bool) (n int32, err error) {
 		}
 
 		// Running -> false
+		tx := db.BeginTx(ctx)
+		if tx.Error != nil {
+			return 0, tx.Error
+		}
 		var sys db.System
-		if err = d.Model(&db.System{}).FirstOrCreate(&sys).Error; err != nil {
+		if err = tx.Model(&db.System{}).FirstOrCreate(&sys).Error; err != nil {
+			tx.Rollback()
 			return 0, err
 		}
-		if err = d.Model(&sys).Updates(map[string]interface{}{
+		if err = tx.Model(&sys).Updates(map[string]interface{}{
 			"running": false,
 		}).Error; err != nil {
+			tx.Rollback()
+			return 0, err
+		}
+		if err = tx.Commit().Error; err != nil {
 			return 0, err
 		}
 		return 1, nil
 	}
 
+	d := db.BeginTx(ctx)
+	if d.Error != nil {
+		return 0, d.Error
+	}
+	readTx := d
+	defer func() {
+		if readTx != nil {
+			readTx.Rollback()
+		}
+	}()
+
 	//// Run selected global+dns+routing.
 	/// Get them from database and parse them to daeConfig.
 	var mConfig db.Config
@@ -513,6 +517,11 @@ func runLocked(d *gorm.DB, noLoad bool) (n int32, err error) {
 		c.Node = append(c.Node, daeConfig.KeyableString(fmt.Sprintf("%v:%v", node.uniqueName, node.dbNode.Link)))
 	}
 
+	if err = readTx.Commit().Error; err != nil {
+		return 0, err
+	}
+	readTx = nil
+
 	/// Reload with current config.
 	chReloadCallback := make(chan error)
 	reloadMsg := &dae.ReloadMessage{
@@ -536,20 +545,37 @@ func runLocked(d *gorm.DB, noLoad bool) (n int32, err error) {
 	}
 
 	// Save running status
+	tx := db.BeginTx(context.WithoutCancel(ctx))
+	if tx.Error != nil {
+		return 0, tx.Error
+	}
+	defer func() {
+		if err != nil {
+			tx.Rollback()
+		}
+	}()
 	var sys db.System
-	if err = d.Model(&db.System{}).FirstOrCreate(&sys).Error; err != nil {
+	if err = tx.Model(&db.System{}).FirstOrCreate(&sys).Error; err != nil {
 		return 0, err
 	}
 	var gvs uint
 	var gids []string
+	groupIds := make([]uint, 0, len(groups))
 	for _, g := range groups {
 		gvs += g.Version
 		gids = append(gids, fmt.Sprintf("%x", g.ID))
+		groupIds = append(groupIds, g.ID)
+	}
+	liveGroups := make([]db.Group, 0, len(groupIds))
+	if len(groupIds) > 0 {
+		if err = tx.Where("id IN ?", groupIds).Find(&liveGroups).Error; err != nil {
+			return 0, err
+		}
 	}
 	sort.Slice(gids, func(i, j int) bool {
 		return gids[i] < gids[j]
 	})
-	if err = d.Model(&sys).Updates(map[string]interface{}{
+	if err = tx.Model(&sys).Updates(map[string]interface{}{
 		"running":                   true,
 		"running_config_id":         mConfig.ID,
 		"running_config_version":    mConfig.Version,
@@ -562,7 +588,10 @@ func runLocked(d *gorm.DB, noLoad bool) (n int32, err error) {
 	}).Error; err != nil {
 		return 0, err
 	}
-	if err = d.Model(&sys).Association("RunningGroups").Replace(groups); err != nil {
+	if err = tx.Model(&sys).Association("RunningGroups").Replace(liveGroups); err != nil {
+		return 0, err
+	}
+	if err = tx.Commit().Error; err != nil {
 		return 0, err
 	}