> To map around this I have a control table with (at the moment) one
> row. Before the recurrent reservation process can run it tries to
> update this row. If it succeeds it keeps the row lock until it haas
> finished the Recurrent run.
>
> Other apps that try to update recurrents cannot get a lock on the row
> and thus drop back to normal operations.

Do you do a commit after updating the 1 row?
If so, what happens if a client crashes just after commiting that 1 row?