SBDavid
Jul 1st, 2009
Jul 1st, 2009
DNS load balancer
DNS load balancer
Load balancing via DNS is achieved by assigning more than one IP address to the same name. For example, to balance the load on http requests for the site example.com, we would add more than one IP address, say 3, to the site. So the site can be accessed with any of the IP address.
The order in which the nameserver answers the dns query for that site is configured by setting ‘rrset-order’ in named.conf file.
For example, the configuration will return A records in round-robin order.
rrset-order {
class IN type A name “*” order cyclic;
};
class IN type A name “*” order cyclic;
};
Other options are,
fixed - returns A record in the order they are defined in the zone file
random - returns A record in some random order
