On Sat, 7 Apr 2001, John Horne wrote:
> So, both the master and slave system must handle all aspects of the vacation
> processing. However, since the 'log' and 'once' files are involved we must
> ensure that they are kept in-sync on both systems.
Forget about Exim for the moment, and think of the requirement. The only
possibly way to do this "properly" is to have the two systems accessing
the same file. It's no good having one system tell the other what it has
done - by that time the other system may have received a message and
sent a second autoreply (and be trying to tell the first system...) This
is likely to be worse after a period when one system is down - there
will be lots of stuff stacked up on the other, which will take some time
to get through.
How can you get the two systems (not really "master" and "slave" if they
can both do the entire job) to use the same file? Well, one way is to
put the file on an NFS filserver, but I know you do not use NFS. The
only other way I can think of is for you to buy a third system, purely
for vacation handling. (Powerful Linux boxes are pretty cheap these
days.) How could you insure against this system failing? You could, for
example, copy the relevant files somewhere else at regular intervals.
(One could conceive of a fourth system that did nothing but receive the
copies and wait as a "hot spare", to be switched in only when
necessary.)
I think the general point I am making is that you can take precautions
against a machine failing by making regular copies of the files, but you
have to use just ONE live file at the actual point of doing the job. I
cannot see any way round this.
> Again, having said all that my thought now is why not simply ditch the 'log'
> file? That allows me to use the nobody address with no problem - *unless*
> this address is also the one recorded in the once file; I have not tested
> this yet.
Of course it is. It's the address that is being sent to. Sorry.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
