From ad4324bb66db411fa697918d1f0008b28f79a9c9 Mon Sep 17 00:00:00 2001
From: andig <andi@evcc.io>
Date: Fri, 10 Jul 2026 07:57:26 +0200
Subject: [PATCH] sqlite: serialize access on a single connection (#30902)

---
 server/db/db.go | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/server/db/db.go b/server/db/db.go
index 1a21b7c52..6e613e1c7 100644
--- a/server/db/db.go
+++ b/server/db/db.go
@@ -73,9 +73,20 @@ func New(driver, dsn string) (*gorm.DB, error) {
 		return nil, fmt.Errorf("invalid database type: %s not in [sqlite]", driver)
 	}
 
-	return gorm.Open(dialect, &gorm.Config{
+	db, err := gorm.Open(dialect, &gorm.Config{
 		Logger: &Logger{util.NewLogger("db")},
 	})
+	if err != nil {
+		return nil, err
+	}
+
+	// sqlite allows a single writer; serialize on one connection so concurrent
+	// writes wait on busy_timeout instead of failing with SQLITE_BUSY.
+	if sqlDB, err := db.DB(); err == nil {
+		sqlDB.SetMaxOpenConns(1)
+	}
+
+	return db, nil
 }
 
 func NewInstance(driver, dsn string) error {