satishkumarp2k1:
>
>
>
> > Is the alias table generated dynamically? It is possible that it's not
> > readable (still being written) at the time the lookup happens?
>
> Yes, correct. All the alias files are generated using perl scripts, which
> run periodically. The scripts actually generate temporary alias files (while
> generating the aliases) and then just use "mv" command to the actual alias
> file. Do you still think lookup might fail even in this case??
The "rename into place" approach is generally safe (except with
moves between across file system boundaries, or with DBM files
which come in pairs).
Renaming a database is definitely safer than overwriting.
However, if a user is added then there is a brief time where a some
Postfix program may still have a handle to the old database copy
that does not have that user. That amount of time is the time needed
to handle a mail delivery request.
Wietse
