When IT staff in a small enterprise considers high availability (HA) for critical applications, they often think of HA as 24/7 continuous availability. However, there is a range of HA requirements that can be defined and implemented that do not require the costs and effort of continuous availability.
By carefully evaluating the business needs for critical applications the key requirements can be defined and translated into an HA implementation. Different applications may require different HA support but all applications can benefit from the process of defining real-world uptime requirements. Evaluation criteria can include:
- When the application is in use.
- Cost to the enterprise for an application outage.
- Time to recover options.
- Client connectivity.
- Support infrastructure.
By categorizing the applications and their availability needs, an appropriate architecture can be developed to cost effectively support those needs. Understand the business requirements for each application before attempting to define and create an infrastructure to support HA.