MailScanner on a cluster

[Julian Field]

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
>>
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>>
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-- 
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

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-- 
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.