Added config for database max connections

docs/config.md

@@ -45,6 +45,9 @@ database:
   Path: "./vikunja.db"
   # Whether to show mysql queries or not. Useful for debugging.
   showqueries: "false"
+  # Sets the max open connections to the database. Only used when using mysql.
+  openconnections: 100
+
 
 cache:
   # If cache is enabled or not

models/config.go

@@ -27,6 +27,7 @@ func InitConfig() (err error) {
 	viper.SetDefault("database.database", "vikunja")
 	viper.SetDefault("database.path", "./vikunja.db")
 	viper.SetDefault("database.showqueries", false)
+	viper.SetDefault("database.openconnections", 100)
 	// Cacher
 	viper.SetDefault("cache.enabled", false)
 	viper.SetDefault("cache.type", "memory")

models/models.go

@@ -27,7 +27,9 @@ func getEngine() (*xorm.Engine, error) {
 			viper.GetString("database.password"),
 			viper.GetString("database.host"),
 			viper.GetString("database.database"))
-		return xorm.NewEngine("mysql", connStr)
+		e, err := xorm.NewEngine("mysql", connStr)
+		e.SetMaxOpenConns(viper.GetInt("database.openconnections"))
+		return e, err
 	}
 
 	// Otherwise use sqlite