3.4.0 Matrix Server Administration Guide

Chapter 3: Configure Servers 42
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new virtual hostname are automatically redirected by Matrix Server to
a backup server.
Configure Servers for DNS Load Balancing
Matrix Server can provide failover protection for servers configured to
provide domain name service (DNS) load balancing. DNS load balancing
allows you to set up servers so that requests are sent alternately to each of
the servers in a matrix. For example, clients could access acmd1 and
acmd2 in turn, enabling the servers to share the load of accepting and
responding to client requests.
DNS includes a round-robin feature using address records (A records) to
alternate requests between IP addresses. This feature provides a
straightforward way to gain load balancing capability and simplified load
balancing, resulting in improved response time.
Matrix Server provides failover protection for this configuration. Without
Matrix Server, requests are simply alternated between the servers. If a
server goes down, requests to that server do not connect.
To configure for round-robin load balancing with Matrix Server, you
define virtual hosts as addresses in the A records on the DNS. Then use
Matrix Server to associate primary and backup servers with that virtual
host. In essence, you use the virtual host capability of Matrix Server to
accept the round-robin requests sent by the DNS. Matrix Server handles
the failover function to the real servers in the matrix.
In the following example, two servers, acmd1 and acmd2, are configured
to accept round-robin requests.