The Basics of Application High Availability

High availability is the ability to maintain continuous operations. It's achieved by implementing redundancy and fault tolerance, two of the main concepts in the application's high availability.

Redundancy is having multiple copies of a component so that another can take its place if one fails. Fault tolerance is the ability to tolerate failures of components—it ensures that an application will continue operating even when some parts are lost or damaged.

Benefits of High Availability

Benefits of High Availability include:

• Reduced downtime. By reducing the risk of failure, you reduce the impact of downtime.
• Reduced risk and cost of failure. By reducing the frequency and duration of failures, you can reduce the costs associated with fixing those problems.
• Increased reliability from up-time availability and fault tolerance (e.g., redundancy). This makes systems more dependable for users so they can rely on them being available when needed, which improves customer satisfaction and security compliance requirements like PCI DSS or HIPAA regulations for healthcare organizations that deal with sensitive data about patients’ medical histories (e.g., names/addresses/social security numbers).

Disadvantages of High Availability

The disadvantages of high availability are:

• Increased complexity
• Increased cost
• Increased risk of data loss
• Increased risk of downtime

Testing for Failover Capability

Testing your application's failover capability is essential in ensuring that the business continuity plan can be implemented properly. The following steps can help you test your application's failover capability:

• Test failover capability in a test environment.
• Test failover capability in a production environment.
• Test failover capability in a development environment.
• Test failover capability in a staging environment; this will help determine whether or not there are any issues with the code or configuration that need to be addressed before rolling out changes into production

Takeaway:

If you're taking a business continuity and disaster recovery class, the concepts of high availability and disaster recovery are familiar. You might even be wondering why we're talking about them in a high application availability and business continuity class—after all, what's the difference?

Critical differences between these terms can make all the difference regarding your software's resilience and longevity. Don't worry, though: we'll go into depth on each of them throughout this module.

But first, let's talk about what exactly makes something "high-available."

Conclusion

In conclusion, high application availability is a service that helps businesses increase their productivity and ensure the continuity of critical systems. It's an essential step in taking care of your information technology infrastructure and ensuring that users have access to their applications even when there are problems with hardware or software. When choosing an application high availability solution, you should consider its cost-effectiveness and reliability level for providing continuous service so that end users are never impacted by outages.