Date: April 9, 2022
Tags: disaster recovery, High Availability
Two Truths and a Lie: Understanding the Real Truth About Availability
We played two truths and a lie at a company event years ago. The game involved putting forth two true statements and one untrue statement to see if you could fool the most people. The winner put forth ideas that all seemed believable or unbelievable, depending on your own personal history. Here is what was said:
- While growing up, my hometown had no stoplights.
- My grandparents met in the second grade and married in their teens.
- After graduation, I attended a prestigious out-of-state university in Georgia before transferring back home to attend an in-state university.
I grew up in a small community with no stoplights, so that one seemed possible, but I was skeptical. I’ve heard stories of people who met at an early age, and got married in their teens, so that was possible but also the one that I might want to flag. The third one also seemed true, but I wondered who would transfer from a prestigious out-of-state university back to the no stoplight hometown to attend an in-state college. For what seemed like an eternity the entire group reasoned and pondered which of the three statements was a lie. And, it seemed as if no one could spot it. Several of us reasoned that if the hometown had no stoplights, would it really have a university as well? A few took the line that it was unlikely he attended the prestigious out-of-state university, given his age, years with the company, and multiple degrees. After final deliberation the verdict was in, the two truths were number one and number two. The lie was number three.
With all the information swirling around about High Availability, you might feel like you are playing a game of “Two Truths and a Lie.” Depending on where you look, you may find statements about availability that seem believable, but are not completely true when you dig in beneath the surface. For example, the following widely accepted statements are not actually true:
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Storage availability is all that is needed for high availability
Applications require access to data to be effective and efficient. Your database will need to have access to storage if you are going to successfully run your enterprise. Your other enterprise application likewise must have access to configuration files, data stores, and transaction and error log directories to be usable. But, while reliable, readily accessible, and performant storage is essential for all enterprise systems, websites, databases, applications, and interconnects, storage available alone is not all that is needed for high availability. There are more components that make up a sound, reliable, resilient high availability architecture than just storage.
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Platform availability is all that is needed for high availability
With the continued development and growth of cloud computing, many enterprises searching for high availability are confused by the concept of platform availability. Platform availability, sometimes referred to as system availability or infrastructure availability relates to the time that the platform (hardware, network, OS, and related components) are accessible and deliver their intended IT service. Applications and databases absolutely need compute, memory, storage, and network resources to operate properly and efficiently. Every service or function in your data center needs a reliable place to execute its logic, and without the underlying platform, these operations are not possible. Because of this, many consider that platform availability is all that is needed for high availability. As VP of Customer Experience, I have helped customers and partners understand the gaps between an available platform and available applications, databases, and client connectivity. In those conversations, we have discussed real examples of platforms showing no downtime or service issues, while simultaneously the enterprise applications running within that data center or cloud infrastructure are unavailable, unstable, or inaccessible to clients due to non-platform issues.
So What’s the Real Truth?
When our co-worker shared his three statements, we all got it wrong. His hometown was a small community, its borders were buffered by larger towns with a stoplight, but his own town did not have one of its own. And, as it turned out, he graduated early and went to that well-known, prestigious out-of-state institute of technology in Georgia, before getting homesick and transferring to an in-state university back home. So the lie was about his grandparents. While they may or may not have met at an early age, they definitely did not meet in the second grade.
The truth about high availability is that storage availability and platform or infrastructure availability are not enough on their own. In order to create the most robust, available, resilient, and reliable high availability infrastructure you must also include a commercial-grade solution to provide application-aware monitoring, alerting and recovery. You’ll also want that solution to be knowledgeable of your storage’s high availability capabilities, have a strong awareness of the infrastructure’s nuances and gaps, and have the ability to leverage best practices across the entire architecture to help your applications, databases, and services achieve your business objectives.