RE: [cobalt-users] RE: Raq4 - Fail Over/Backup Email for a domain..

["Jerry Farquhar" <jerry@xxxxxxxxxxx>]

I doubt the budget is going to be able to reach into the stratosphere of $$
you mentioned but the wallet is open for this customer.  They have been told
to expect an expenditure of $20-50K+ to achieve about the best case
arrangement.. and I have not heard any comments back as of yet.

Personally and I think most of us here in the forum would agree that this
kind of uptime isn't work the expense.  In my own opinion even an outage of
up to 24 hours per year is still not even bad or something that should have
a overwhelming impact on anyone's business.  I look at it like the weather..
it's nice one day and the next day there's a blizzard and the roads are
closed (as are most business's).  Take it in stride and carry on.

FYI - Regarding the situation for doubled up email accounts per user.. I
don't see that as a problem at all if users are using Mozilla or other
similar email client that separates each account as well as their folders
(Inbox, Sent, Deleted, etc..)

So.. back to my original issue.. is it possible to set the MX record to send
with the same priority email messages to two separate domains?  Do you know
of anyone who has tries it?

Jerry..


PS - Thanks for understanding what I'm trying to accomplish.  Your comments
are always welcome.

-----Original Message-----
From: cobalt-users-admin@xxxxxxxxxxxxxxx
[mailto:cobalt-users-admin@xxxxxxxxxxxxxxx]On Behalf Of Gavin
Nelmes-Crocker
Sent: Saturday, December 21, 2002 11:35 AM
To: cobalt-users@xxxxxxxxxxxxxxx
Subject: RE: [cobalt-users] RE: Raq4 - Fail Over/Backup Email for a
domain..


> Like I have said in response to another post on this list....not even
> god himself needs 100% uptime. No provider can guarantee 100% uptime
> because it is not financially viable.....never mind what their marketing
> department promises. Having said that, there is a solution you can apply
> that will meet your needs. As I understand it, you are simply trying to
> ensure that mail addressed to your domain doesn't get bounced back in
> the event your mail server is down. So...here's what you do...You have
> your primary mail server which accepts all mail for your domain. Make
> sure the MX record is set at the highest priority. Then you come up with
> a secondary mail server and set the MX priority for it just a little
> lower than the primary. Now, if the primary fails, the mail will start
> flowing to the secondary. The secondary server will queue it and forward
> it to the primary when it comes back up. Hope this helps!

Kapil - I think you may have missed the finer point of Jerry's
idea/requirement its not so much for the mail or queuing but for the users
so that if the primary mail server goes down mail will still be delivered to
a mail server that the users can query with a simple change to their mail
client.

There are some drawbacks that I can see first off if all mail is delivered
to 2 servers regardless of whether the primary is up or down (assuming for
the moment that you can achieve that) what happens in the situation when the
user does log in to that second server they will have all the mail that they
have deleted when they got it the first time around.

The proper way as I understand it and this can provide 99.999% uptime i.e.
only 5 minutes per year down which is Telco standard, six nines is Military
grade is the following.  BTW this is an open cheque book scenario if anyone
has this and wants to give me a call I'll happily put a worldwide team
together to implement it but expect an initial bill in the order of half a
million US$ to get going.  If you used more than 2 sites I expect you could
make it military standard (30 seconds downtime in a year)

First off you need a minimum of 2 data centres far enough apart that the
following won't affect both: earthquake, tsunami, major bomb or plane crash.
Now you need to link them via massive and redundant fibre.  Ok now you need
to install a SAN at each location that mirrors to the other this is where
you will store the mail.  Next you need a Database cluster at each end that
also mirrors this is where you will store the user information.  Now you
need to build your mailservers Qmail works well with this as it will hook up
with MySQL for user data call each mail server mail1.domain.com -
incrementing as required then put a load balancer with hot spare in front of
the mailservers at each site then you need to put Global load balancing in
front of the whole thing so you end up with just one mail.domain.com.

Now it won't matter which server or which site goes down as users will
always get a connection as long as they can see the net of course.  You can
expand this as much as your wallet will allow.

Now the problem is getting Cobalt's to do this - Qmail will install so I
suppose you could use RaQ550 as your front end mailservers but that's about
all.

BTW this isn't theoretical this system does exist for at least one company
in the UK with multiple sites around the world so I know it works.

Jerry I take it the budget won't stretch to this <smile>

Regards

Gavin


_____________________________________
cobalt-users mailing list
cobalt-users@xxxxxxxxxxxxxxx
To subscribe/unsubscribe, or to SEARCH THE ARCHIVES, go to:
http://list.cobalt.com/mailman/listinfo/cobalt-users