Hello Michael,

In theory, ther'es always potential, particularly when dealing with files on disk. One program could in theory do one thing and not
another.

The MySQL database should deal with its own concurrency. The CDB database has .vpasswd.lock files when updating the password files.

You probably don't have to worry about corrupting anything, but in theory one could get system time and do something unexpected on the other, particularly in deleting and creating folders. That's usually
 not that important.  Odds are that's never going to happen that you
do two opposite actions on the same [EMAIL PROTECTED] at the same time.

Odds are, you won't cause any harm.

Thank you for your help.
I've been thinking about what you said ...

The vpop commands will
1) Insert/Update/Delete the record in SQL table (such as MySQL)
   or CDB file
2) Create/Update/Delete the folder/file on the local file system.
I don't know the order, but it will not matter.

As for (1), SQL database and CDB have their own mechanism to serialize the concurrent access, so we will not worry about it.

As for (2), there may be a chance of conflict in theory, because vpop commands do not implement the mechanism to avoid the concurrent access. But, in the real world, it is the rare case that the same folder is created/deleted at the same time.
For example, at the time when someone is creating
   /home/vpopmail/domains/foo.com/tom
there will be nobody to delete it.

So, we need not to worry about the concurrent usage of vpop commands.
Is my understanding correct?

Have a nice weekend.

Jun

Reply via email to