Introduction to Networking for NonStop NS-Series Servers (H06.03+, J06.03+)

Networking on Integrity NonStop Servers
Introduction to Networking for HP Integrity NonStop NS-Series Servers—529874-003
1-9
Integrity NonStop Server Networking Compared to
Other Platforms
•
Clients on subnet 192.168.4.1 requesting the IP address of MyCompany.com
receive the IP address of Webserver 4.
Figure 1-2 on page 1-8 shows transparent network scalability on multiple hosts.
The other way of achieving transparent network-level scaling is to use DNS round-
robin address rotation where one DNS name server process returns different IP
addresses for a given resource service. With this technique, you would ensure there is
a different network interface associated with each IP address; one name server
process would then answer requests for the name with those IP addresses on a
rotating basis. In Figure 1-3, the DNS server process rotates Webserver requests for
Mycompany.com among interfaces 1.1.1.1, 1.1.2.1, 1.1.3.1 and 1.1.4.1. (On a multi-
homed NonStop server, the separate systems shown in Figure 1-3 are contained in
one system.)
See the DNS Configuration and Management Manual for more information about
configuring a DNS name server process on your NonStop server.
Application Scalability
Application scalability refers to distributing application-service load across multiple
instances of the application server process. In the example of the scaling mechanism
provided by DNS, the service application (the web server process) is limited when the
server instances need to share data that is not resident on all the hosts. For example,
a set of web server processes distributed over n hosts must either have the data it is
servicing duplicated across those hosts or connect to a back-end shared database so
Figure 1-3. DNS Round-Robin Address Rotation
vst029.vsd
Webserver 1 Webserver 2 Webserver 3 Webserver 4
Four servers for mycompany.com
DNS server
(named)
The name server returns the IP addresses of the web
servers for mycompany.com on a rotating basis so
that the network traffic is distributed among the four
network interfaces
1.1.1.1
1.1.2.1
1.1.3.1
1.1.4.1