Can we load balance traf[f]ic for CNAME records?
fenghe at nsbeta.info
Fri Dec 14 09:24:17 UTC 2012
于 2012-12-14 17:14, Manish Rane 写道:
> I understand that Mail Delivery load balance can be achieved by usingMX
> priorities. My concern is not that, rather I am more worries about users
> who will be using A record to configure their mail clients like IMAP or
> POP. I am thinking on load balancing their since I want users to access
> the both the ISPs to connect. I can have A/CNAME? record configured in
> my zone with *lower TTL value say 180* so that if any of the link goes
> down I can edit the zone and have the faulty entry removed which
> eventually would cost me less downtime. That way I dont need to do any
> configuration at client end since the A/CNAME record is gonna be the same.
> That is why I was wondering if A or CNAME can be configured for two
> different IP addresses which also holds MX Records and thus configure
> the load balancing by that way?
There are two ways of setup that.
the first, for example, imap.example.com has two A records,
imap.example.com. 900 IN A 18.104.22.168
imap.example.com. 900 IN A 22.214.171.124
If one server go down, half of the users have the chance to use the
the second, imap.example.com has only one A record,
imap.example.com 900 IN A 126.96.36.199
when this server go down, you change the record value to another IP by
hand. that's no problem for the clients ,but you must do it by hand. Or
write a script to do this automatically for you.
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