What Is High Availability Architecture and Best Practices to Enable It

What Is High Availability Architecture and Best Practices to Enable It

We’re dependent on the Internet; and the internet? It’s dependent on high availability architecture.

What would you do if it just stopped working one day? No work. No social media sites. No streaming channels. What would we do with ourselves? 

Hopefully, we never have to find out because this article explains how to get better at hardware, software, and data redundancy.

Today, we discuss how we can keep everything up and running by explaining high availability architecture, some best practices for it, and some basic advantages to using Environment as a Service (EaaS) to ensure high availability. We’ll mention an amazing EaaS solution from Bunnyshell at the end.

What Is High Availability Infrastructure?

High availability refers to an operational component or system without any interruptions for extended periods. A highly available infrastructure accounts for multiple components working together to guarantee uninterrupted service during a specific period. So implementing a high availability infrastructure is the solution to unplanned downtime and avoiding service disruptions

Seeing as how we’re dependent on the Internet, every second counts, so company computers and servers must always be operational. Downtime can lead to data loss. So when setting up your IT infrastructure, high availability becomes the first thing to think about. Uninterrupted service means that the response time to users’ requests also has to be timely; meaning that available systems have to be online and responsive

High availability infrastructure has the capacity to recover from unforeseen circumstances in the shortest time possible. It moves the processes to backup components, minimizing downtime or completely eliminating it. This requires constant monitoring, maintenance, and in-depth tests to ensure that there are no weak points. The best way to ensure the continuous operation of critical apps and services is to implement a cloud computing architecture

Hardware vs Software vs Data

A high availability architecture has the following components: 

- Hardware redundancy 

- Software and application redundancy 

- Data redundancy 

Calculating Availability Percentage & Level of Redundancy

The Table of Nines

Availability is calculated by how much time a system remains fully operational during a specific period. This usually means one year. Uptime is when a system is up and running, but unavailable to users because of network or load balancing issues. Uptime is calculated by referring to the availability levels from the table of nines, included below.

Availability Levels Maximum Downtime per Year Downtime per Day
One nine (90%) 36.5 days 2.4 hours
Two nines (99%) 3.65 days 14 minutes
Three nines (99.9%) 8.76 hours 86 seconds
Four nines (99.99%) 52.6 minutes 8.6 seconds
Five nines (99.999%) 5.25 minutes 0.86 seconds
Six nines (99.9999%) 31.5 seconds 8.6 milliseconds

Businesses and organizations have different availability needs, but most aim for at least three nines (99.9%). Those who wish to remain operational throughout the year and around the clock will aim for five nines (99.999%) of uptime. Notice that 100% availability is not an option. This is because no system is entirely failsafe, and the move to backup components takes some time (either milliseconds, minutes, or hours). 

The Main Models of Redundancy

Infrastructures must have backup components to replace the failed system in case of natural disasters or a power or hardware failure. One way to have high availability, in this case, is to remove single points of failure to achieve redundancy on all levels. 

The different levels of component redundancy include:

  • The N+1 model (where N = amount of equipment) - This model is operational with one individual backup component per each of your primary components in case of a system failure. It’s usually active/passive (where it’s primary component/backup component), which means that backup components wait for a failure to occur before becoming operational. But this model can also be active/active, which means that backup components work in conjunction with primary components. The N+1 model is not an entirely redundant system. 
  • The N+2 model - This model is similar to the N+1 model, with the difference being the ability to withstand the failure of two primary components. 
  • The 2N model - This model contains double the amount of each individual component needed to run the system. With this model, you can move the operations entirely to the backup components without worrying about whether a failure of one component or the whole system occurred.  
  • The 2N+1 model - This model is similar to 2N, with an extra component for added protection. 

High Availability in Software Development

High availability environments continuously monitor the system’s performance through complex server clusters with system software. Avoiding unplanned equipment downtime is a top priority. If one piece of hardware fails during production time, it shouldn’t cause a complete service halt. In this sense, one can say that software design and production environments aid in high availability architecture. 

Most downtime is the product of human error rather than faulty architecture. You can try to set up an endless amount of backups, servers, and redundancies to attempt to reach a better uptime. But one of the simplest ways to avoid downtime is to implement better processes to test and manage changes, tracking errors, and finding bugs. A good solution to this? Implementing a cloud computing architecture, which also opens up the potential of using multiple environments for testing, staging, and backups. Take a look at some best practices before migrating to a cloud-based solution.  

Best Practices for High Availability Infrastructure

Cloud computing solutions have become the more flexible and cost-reducing option over in-house solutions in recent years. You don’t need to pay on-site data storage costs, and it improves redundancy while eliminating overhead. Additionally, the cloud platform allows for resource scaling, improves collaboration, and ensures data availability. Below we go over some best practices to adopt the appropriate cloud-based architecture solution for your business. 

Conduct an Assessment

The first step to moving forward and joining the rest of the world is to assess your needs. Go over what you already have in place, and then assess what you need going forward. In this way, you’ll be able to alleviate any pain points after migration to a cloud-based architecture. Ask yourself:

  • What skills do I need; do I already have them in-house?
  • What workloads need to be migrated, and how?
  • Are new roles needed to maintain the cloud computing services?

Once you have gathered the answers to these important questions, you’re ready to move on to the next step towards high(er) availability.

Look Into Cloud Computing Providers and Services

There are different types of cloud-based delivery models and services, all of which address specific business needs. Understanding the different types will make migrating your business to the cloud much easier:

- Software as a Service (SaaS) - SaaS is a model in which cloud providers host applications or databases via the Internet. Applications can also be known as on-demand, web-based, or web-hosted software. 

- Infrastructure as a Service (IaaS) - IaaS is a model that allows you to outsource your data center. You are not required to purchase hardware equipment as you’re charged based on the amount of resources allocated and consumed (based on a utility computing basis).

- Platform as a Service (PaaS) - PaaS includes facilities for application development, testing, and deployment, web service integration, team collaboration, scalability, security, application versioning, and more. 

- Environment as a Service (EaaS) - EaaS, a natural extension of IaaS, is an all-in-one application environment. It uses automation to perform server configuration. EaaS also allows applications to run across multiple cloud or data center platforms with a click of a button. 

After researching available cloud solutions for your business needs and inspecting its history with cloud security, you are that much closer to developing a migration plan for moving your workloads. 

Consider Microservices 

In addition to a cloud solution, an excellent option for high availability is microservices. We know that an infrastructure serves as one self-contained system, which means that it’s simple to manage, but you’re essentially putting all your eggs in one basket. If something happens, the whole system goes down. Microservices, on the other hand, explained more in-depth in our Microservices in a Nutshell article, helps break down different application functions into individual systems that can be integrated with each other. If any one piece suffers downtime, the whole application is only partially affected. 

However, adding microservices will add operational complexities. You would need to ask yourself some pertinent questions before considering adopting microservices:

  • Do you know what microservices are and how they influence development operations? 
  • Is your team skilled enough to handle the implementation of microservices?
  • What is your vision on scaling up? An infrastructure designed with scalability in mind is effective only when you plan to expand your product and your market.

Basic Advantages of Using EaaS to Ensure High Availability

An EaaS can support high availability infrastructure in a number of ways. 

Make sure to train employees on procedures and best practices concerning security. EaaS can offer online training environments where participants can access sessions from any device or location, making training employees extremely easy.

Also, the EaaS model is highly scalable, saving you money by allowing you to focus only on the resources you need. 

Additionally, you can create environments more efficiently with an EaaS. This translates into creating redundant environments that can be available as backups to ensure high availability for devs building an app during staging and development and for users during production and deployment.

Furthermore, an infrastructure migration is typically prone to security breaches or data loss. You need to protect your entire business, regardless of where your data is stored. With an EaaS that detects malware and protects you from attacks, you get full control of your infrastructure.

For more benefits to using an EaaS, check out our Benefits of Environment as a Service article.

Go for Six Nines With EaaS

The cost of downtime will end up costing you more money, resources, and data (not to mention that your reputation can suffer permanent damage), than if you implement a high availability infrastructure. 

Bunnyshell understands how important high availability and staying operational without interruptions is. We can help you integrate the best cloud computing architecture out there: EaaS. You can quickly and easily spin up a high availability database cluster while backups, updates, and maintenance are completely taken care of so you can aim for 99.9999% uptime. Don’t get left behind as the rest of the world adopts this cloud solution. 

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