MailScanner on a cluster
Julian Field
MailScanner at ecs.soton.ac.uk
Tue May 23 08:34:17 IST 2006
I have never tried building it into a true compute cluster, but I do
know people who have used Cisco load balancers with considerable
success.
Sorry, never played with Mosix (not in the last 10 years, at least, I
did some compute cluster work before that).
On 23 May 2006, at 08:22, Dave Strydom wrote:
> DAMNIT, gmail doesnt like the tab key...
>
> anyways, i have for example this:
>
> @ IN MX 10 smtp.mailserver.com.
> IN MX 20 smtp2.mailserver.com.
>
>
> then in the mailserver.com zone file i have:
>
> smtp IN A 192.168.0.146
> IN A 192.168.0.162
>
> smtp2 IN A 172.172.0.251
> IN A 172.172.0.251
>
>
>
> The smtp2 record isn't what i am concerned about, what I want to do is
> find a way to keep the MX and A records exactly the way they are.
>
>
> You see, the two mailservers for smtp.mailserver.com sit inside a DMZ,
> now I want to add more servers to process the mail, but i dont want to
> increase the amount of IP's or DNS records.
>
> I think the only way i am going to get this right is to put them
> behind a cisco and get the cisco to do the load balancing, but what I
> am trying to establish is if its possible to setup MailScanner in
> Mosix type setup, where the load is distributed amount the servers.
>
> I fully understand the way of doing it via DNS, but i want to try
> avoid that way.
>
>
> Dave
>
> On 5/23/06, Dave Strydom <strydom.dave at gmail.com> wrote:
>> At the moment i have something like this:
>>
>>
>> @
>>
>> On 5/22/06, Julian Field <MailScanner at ecs.soton.ac.uk> wrote:
>> >
>> >
>> > Dave Strydom wrote:
>> > > Julian,
>> > >
>> > > I'm already using the DNS round-robin system of both solution
>> 1 and
>> > > solution 2, there is just one problem...
>> > >
>> > > These mailscanners are part of a webhosting setup and handle
>> mail for
>> > > about 2500+ different domains, I don't want to have to go
>> update all
>> > > MX records everytime i want to add an additional server. Also
>> some
>> > > people handle their own DNS records, so then it's a mission to
>> send
>> > > out notifications and asking people to sort out their MX records.
>> > If you use solution 1, then everyone just has 1 MX record in
>> their DNS
>> > records.
>> >
>> > And for any of your customers that have anything else, expand
>> out their
>> > MX records into an equivalent set of A records for your cluster.
>> You
>> > don't need them to change anything, do you? You might just have
>> to make
>> > them all list an MX server in a DNS domain under your direct
>> control.
>> > >
>> > > What I am looking at doing is keeping my current "external
>> ip's" and
>> > > then having them nat into a cluster, but i want to know if I
>> can run
>> > > mailscanner on something like an openmosix cluster, this way I
>> can
>> > > just add servers to the cluster and not have to worry about
>> additional
>> > > ip's and the updates that go with it.
>> > >
>> > > Dave
>> > > On 5/22/06, Julian Field <MailScanner at ecs.soton.ac.uk> wrote:
>> > >> Dave Strydom wrote:
>> > >> > Please excuse my ignorance, but can anyone point me in the
>> right
>> > >> > direction of:
>> > >> >
>> > >> > a) is it possible to run MailScanner on a cluster
>> > >> Yes.
>> > >> > b) If so, can you please point me to some documentation so
>> i can read
>> > >> > up on it please.
>> > >> It's very easy.
>> > >> At the simplest level, which actually works remarkably well
>> considering
>> > >> how cheap the solution is, is this:
>> > >>
>> > >> Solution 1
>> > >> ===========
>> > >> Create a new DNS record called mx.yourdomain.com and assign
>> multiple
>> > >> 'A'records to it, one for each of the IP addresses used by
>> your cluster
>> > >> of servers.
>> > >> Put a single 'MX' record in your domain's DNS records,
>> pointing to
>> > >> "mx.yourdomain.com." (Don't forget the "." on the end).
>> > >>
>> > >> @ 10 IN MX mx.mydomain.com.
>> > >> mx IN A 192.168.99.101
>> > >> IN A 192.168.99.102
>> > >> IN A 192.168.99.103
>> > >> IN A 192.168.99.104
>> > >> IN A 192.168.99.105
>> > >>
>> > >> It's as simple as that. The DNS lookups will rotate through
>> the members
>> > >> of your cluster, spreading the messages (by quantity, not by
>> size)
>> > >> across your cluster.
>> > >>
>> > >> Solution 2
>> > >> ===========
>> > >> You can also do this by having multiple MX records all with
>> the same
>> > >> priority number, each pointing to mx1, mx2, mx3, mx4 etc.
>> > >>
>> > >> @ 10 IN MX mx1.mydomain.com.
>> > >> 10 IN MX mx2.mydomain.com.
>> > >> 10 IN MX mx3.mydomain.com.
>> > >> 10 IN MX mx4.mydomain.com.
>> > >> 10 IN MX mx5.mydomain.com.
>> > >> mx1 IN A 192.168.99.101
>> > >> mx2 IN A 192.168.99.102
>> > >> mx3 IN A 192.168.99.103
>> > >> mx4 IN A 192.168.99.104
>> > >> mx5 IN A 192.168.99.105
>> > >>
>> > >> Some people argue that this is better as it is more likely to
>> deliver
>> > >> mail quicker when you take some of your servers out of
>> action. They are
>> > >> possibly right.
>> > >>
>> > >> Solution 3
>> > >> ===========
>> > >> You can also do this by spending a fortune on Cisco load
>> balancers and
>> > >> have heartbeat monitoring systems, etc. But it won't make any
>> big
>> > >> difference, but you will have a very expensive Cisco box to
>> look after
>> > >> and a big hole in your bank balance.
>> > >>
>> > >> Again, can someone please put this in the Wiki for me?
>> > >>
>> > >> --
>> > >> Julian Field
>> > >> www.MailScanner.info
>> > >> Buy the MailScanner book at www.MailScanner.info/store
>> > >> Professional Support Services at www.MailScanner.biz
>> > >> MailScanner thanks transtec Computers for their support
>> > >>
>> > >> PGP footprint: EE81 D763 3DB0 0BFD E1DC 7222 11F6 5947 1415 B654
>> > >>
>> > >>
>> > >> --
>> > >> This message has been scanned for viruses and
>> > >> dangerous content by MailScanner, and is
>> > >> believed to be clean.
>> > >> MailScanner thanks transtec Computers for their support.
>> > >>
>> > >> --
>> > >> MailScanner mailing list
>> > >> mailscanner at lists.mailscanner.info
>> > >> http://lists.mailscanner.info/mailman/listinfo/mailscanner
>> > >>
>> > >> Before posting, read http://wiki.mailscanner.info/posting
>> > >>
>> > >> Support MailScanner development - buy the book off the website!
>> > >>
>> >
>> > --
>> > Julian Field
>> > www.MailScanner.info
>> > Buy the MailScanner book at www.MailScanner.info/store
>> > Professional Support Services at www.MailScanner.biz
>> > MailScanner thanks transtec Computers for their support
>> >
>> > PGP footprint: EE81 D763 3DB0 0BFD E1DC 7222 11F6 5947 1415 B654
>> >
>> >
>> > --
>> > This message has been scanned for viruses and
>> > dangerous content by MailScanner, and is
>> > believed to be clean.
>> > MailScanner thanks transtec Computers for their support.
>> >
>> > --
>> > MailScanner mailing list
>> > mailscanner at lists.mailscanner.info
>> > http://lists.mailscanner.info/mailman/listinfo/mailscanner
>> >
>> > Before posting, read http://wiki.mailscanner.info/posting
>> >
>> > Support MailScanner development - buy the book off the website!
>> >
>>
> --
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>
> Before posting, read http://wiki.mailscanner.info/posting
>
> Support MailScanner development - buy the book off the website!
--
Julian Field
www.MailScanner.info
Buy the MailScanner book at www.MailScanner.info/store
PGP footprint: EE81 D763 3DB0 0BFD E1DC 7222 11F6 5947 1415 B654
--
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.
MailScanner thanks transtec Computers for their support.
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