HP Serviceguard A.11.20- Managing Serviceguard Twentieth Edition, August 2011

Providing Online Application Reconfiguration
Most applications have some sort of configuration information that is read when the application
is started. If to make a change to the configuration, the application must be halted and a new
configuration file read, downtime is incurred.
To avoid this downtime use configuration tools that interact with an application and make dynamic
changes online. The ideal solution is to have a configuration tool which interacts with the application.
Changes are made online with little or no interruption to the end-user. This tool must be able to do
everything online, such as expanding the size of the data, adding new users to the system, adding
new users to the application, etc. Every task that an administrator needs to do to the application
system can be made available online.
Documenting Maintenance Operations
Standard procedures are important. An application designer should make every effort to make
tasks common for both the highly available environment and the normal environment. If an
administrator is accustomed to bringing down the entire system after a failure, he or she will
continue to do so even if the application has been redesigned to handle a single failure. It is
important that application documentation discuss alternatives with regards to high availability for
typical maintenance operations.
Minimizing Planned Downtime 353