IT Solutions
What is a High-Availability strategy?
High Availability is the high degree of availability and functionality of a service or application. It is measured based on the user’s perception and defined by reliability, recoverability, error detection and continuous operation.
Reliability – Reliable hardware equipment is a key component of any high availability solutions, just like software applications, databases, web servers, email servers, file servers and so on.
Recoverability – There could be many possible solutions for recovery from a critical situation. It is very important for any business to know what those critical situations and recovery solutions are, so that key business processes are not affected.
Error detection - the implementation of a recovery plan requires a mechanism for monitoring and detecting possible malfunctions in case a key component of an IT infrastructure becomes inoperable. The mere existence of a recovery plan is useless without continuous monitoring and reporting procedures that trigger each stage of the recovery plan.
Continuous operations - continuous operation is essential when the maintenance activities for infrastructure must be transparent to users and business processes. When the maximum acceptable disruption (downtime) of a service or application tends to zero, any operation such as relocating equipment or replacing any hardware unit must be transparent to users and not affect business processes.
The Importance of a High-Availability solution
The Importance of a High-Availability solution can vary from business to business. However, what is generally true is that successful organizations tend to accelerate business processes by redesigning their IT infrastructure in order to gain a high advantage in front of their competitors. This trend generates more and more a need for solutions that ensure availability and access to information so that the business processes operate at maximum functionality and without downtime. Downtime causes lack of productivity. It deteriorates business relations, generates financial losses and negative publicity. It is not always easy to calculate the real cost of resulting downtime. If an interruption of a critical service or application takes less than 30 seconds, the impact is most often acceptable, even transparent, but as downtime increases, the effect of a minor problem can become a major one, leading to large losses. Many companies choose to protect themselves against critical situations with insurance policies when a high-availability solution is, in fact, the most competitive policy.
What does the implementation of an HA solution mean?
The nature of global businesses has created a necessity for High-Availability solutions in various business components. However, organizations that implement a High Availability strategy have to conduct a thorough analysis of all key components of the business to know what equipment they need to give up, what systems and solutions they need to invest in, how to rebuild the entire IT architecture according to the implemented HA model, how to redefine business processes and so on.
With higher availability, downtime is reduced according to the table below:
Thus, an organization with increased High Availability requirements should choose fault-tolerant (redundant) equipment and solutions to ensure that the risk of downtime tends to zero. The items that have to be analyzed to find optimal HA solutions are: Business Impact Analysis, Cost of Downtime, Recovery Time Objective and Recovery Point Objective. Also, the fact that business processes within an organization are divided by level of criticality, level 1 being the highest and 3 being the lowest, should be taken into consideration. Two other important aspects in achieving a high availability strategy are: estimating future business growth and scalability of existing architecture.
