I have a problem. My magento puts itself to maintenance mode without maintenance.flag. At this time i did not do any installations or backups. Last time this happened i restore the database to last day and all was ok, but now i cannot restore database to the day when magento is working.
The Maintenance mode is just an include of the "503.php" which is located in the errors directory of your Magento installation. There exist only two possibilities when this file is going to be included:
- the maintenance.flag file exists in the root directory of your magento installation (see index.php)
- you are using Redis and expired the maximum of concurrency connections
As you already mentioned, none of these cases match your problem.
Maybe an extension will raise the maintenance mode by including the errors/503.php of the errors directory. Please search all your (custom) code for "503.php". It is possible that some of your extensions need another resource which is not present.