Ofer Inbar:
> > > What I'm trying to understand is *why* it's hitting the limit.
> >
> > If you wonder why 2.5 qmgr uses MORE file dscriptors than 2.2, that
> > has to do with small improvements so that qmgr can keep more delivery
> > agents "busy". Each delivery agent corresponds with one qmgr socket.
>
> My question is more about trying to understand what it's doing.
With Postfix 2.4, the number of the highest file descriptor is not
necessarily equal to the number of open files - 1.
Postfix 2.4 qmgr avoids using file descriptors < 128. These file
descriptors remain available for non-Postfix library code that uses
select() and that would break with file descriptors >= 1024.
If the kernel enforces the open file limit by controlling the
largest file descriptor number, then Postfix can exceed the open
file limit when the number of open files is smaller.
Wietse
