Hostname Standards

In order to achieve maximum flexibility during normal operations, maintenance, disaster recovery, and business continuity efforts, it is important to provide a naming standard for business functions that can be translated easily into hostnames and/or aliases. The purpose of using hostnames instead of IP addresses is that they are easier to remember and use. Hostnames are not necessary, but usually desirable.

Normal user access to an application or business function will always be through an alias. Normal users should never access a system using a hostname. The reason is for portability and availability. It is easy to redirect an alias to any host, it is significantly more difficult to change hostnames. By having the users access required services through aliases rather than hostnames, the users can be redirected quickly to available services in the event of a failure.

Hostnames

In CGE's environment, a hostname refers to an IP address, the IP address is associated with one or more network adapters. It is important to recognize that an IP address is not necessarily tied to a network adapter, but may float across adapters and machines. The same is true with the hostnames. A hostname should be viewed as being independent from any machine or data center. The hostname shall be an enterprise wide unique value in order to eliminate conflicts during manual, automated, or disaster recovery failovers.

The hostname shall consist of exactly 10 characters with the following structure:

LocationCode + OS Type + Environment + ApplicationCode + SequenceID
   3 char    + 1 char  +    1 char   +      3 char     +   2 char   =  10 char

The detailed information for each component of the resource group name is described below:

HostName
Component 		Number of
Characters 		Values
Location Code 3 
ddc = Dallas Data Center
mdc = Mesquite Data Center
OS Type 1 
a = AIX
s = Sun
Environment 1 
a = acceptance
a = pre-production
d = test/development
p = production
t = test
x = disaster recovery
x = pre-production
Application Code 3 
atl = Atlas
ega = EGATE
nim = NIM
ora = Oracle
tps = Maximo
vio = Virtual I/O
Sequence ID 2 
0-9,A-Z,a-z

Examples of Hostnames (HN):

  • ddcapega01
    EGATE Production database on AIX at Dallas Data Center, first instance

  • ddcapega01
    EGATE Production database on AIX at Dallas Data Center, second instance

  • mdcapnim01
    Production Network Information Manager on AIX at Mesquite Data Center, first instance

  • ddcapnim01
    Production Network Information Manager on AIX at Dallas Data Center, first instance

  • mdcapvio01
    Production Virtual I/O Server on AIX at Mesquite Data Center, first instance

  • mdcapvio02
    Production Virtual I/O Server on AIX at Mesquite Data Center, second instance

  • mdcapvio03
    Production Virtual I/O Server on AIX at Mesquite Data Center, third instance

  • mdcapvio04
    Production Virtual I/O Server on AIX at Mesquite Data Center, fourth instance

  • ddcaavio01
    Acceptance Virtual I/O Server on AIX at Dallas Data Center, first instance

  • ddcaavio02
    Acceptance Virtual I/O Server on AIX at Dallas Data Center, second instance

  • ddcaavio03
    Acceptance Virtual I/O Server on AIX at Dallas Data Center, third instance

  • ddcaavio04
    Acceptance Virtual I/O Server on AIX at Dallas Data Center, fourth instance

    • Aliases

    The rules for defining alias names are significantly less rigid than for hostnames. The alias can be any name as long as it is unique within the domain. This allows the application to be accessed though a name that makes logical sense to the user. For example, the production EGATE Application Server at the Dallas Data Center may have a hostname of "mdcapega03", however the alias may be "mdcegate". The use of aliases preserves the structure needed for hostnames and the ease of use desired by users.