HP ProLiant DL380G5-WSS 3.7.0 HP StorageWorks HP Scalable NAS File Serving Sof - Page 78

The addresses on the domain name server are virtual_acmd1 and virtual_acmd2. Two virtual hosts have also been created with those names. The first virtual host uses acmd1 as the primary server and acmd2 as the backup. The second virtual host uses acmd2 as the primary and acmd1 as the backup. The DNS server is configured for round robin using the following A records: Address Time to Live Service www.acmd.com. 60 IN www.acmd.com. 60 IN Record Type A A IP Address 10.1.1.1 10.1.1.2 Address: The virtual hostnames that customers use to send requests to your site. (The period following the ".com" in the address is required.) Time to Live: The number of seconds an address can be cached by intermediate DNS servers for load balancing. This value should be relatively brief so that the addresses of non-functioning servers are not cached by intermediate DNS servers for long periods of time. Service: Always IN for internet. Record Type: Always A for address. IP address: The IP addresses for the virtual hosts you will use for each server in the cluster. These are the IP addresses that the DNS will use to send alternate requests. (In this example, virtual host virtual_acmd1 uses IP address 10.1.1.1 and virtual host virtual_acmd2 uses IP address 10.1.1.2.) With this setup, the domain name server sends messages in a round-robin fashion to the two virtual hosts indicated by the IP addresses, causing them to share the request load. Each virtual host has a single primary server on which it performs its work; the other server is a backup in case the primary goes down or is taken offline for maintenance. Depending on your needs, more complicated combinations of DNS round robin and HP Scalable NAS can be used, including cluster configurations with multiple failover-protected load-balanced servers. 78 Configure servers