Cloud computing is now the foundation of many business solutions for a number of significant business-critical reasons, one of which is the fact that cloud computing—and the cloud ecosystem as a whole—is a lot more reliable (and easier to maintain) than on-premise hardware implementations. Clusters of servers that form today’s best cloud environments are designed from the ground up to offer higher availability and reliability.AWS, for example, when leveraged to its fullest capabilities, offers high availability. You also have the option to set up redundancies and take the reliability of your cloud environment to a whole other level. It is worth noting, however, that hardware failure is still a risk to mitigate, even with Amazon’s robust AWS ecosystem. This is where fault tolerance and redundancy are needed.
Before we can discuss how a cloud environment can be made more reliable, we need to first take a closer look at the two approaches to do so: increasing fault tolerance and redundancy. The two are often seen as interchangeable or completely similar, but fault tolerance and redundancy actually address different things. Redundancy is more for components or hardware. Adding multiple EC2 instances so that one can continue serving your micro-service when the other powers down due to a hardware issue is an example of using redundancy to increase your solution’s availability. Servers, disks, and other components are made with multiple redundancies for better reliability as a whole.Fault tolerance, on the other hand, focuses more on systems. The cloud computing networks, your S3 storage buckets, and even Amazon’s own services such as Elastic Load Balancing (ELB) are made to be fault-tolerant, but that doesn’t mean all AWS services and components are the same. You still need to treat services like EC2 seriously to increase availability.
One big advantage of using AWS when it comes to availability and fault tolerance is the fact that you can leverage Amazon’s experience in handling disasters and recovering from them. Just like other cloud service providers, Amazon deals with outages caused by power problems, natural disasters, and human error all the time. They’ve gotten good at it too.Amazon’s 99.5% SLA is about as good as it gets. You can still expect several hours of downtime every year, but that’s not a bad standard at all. In fact, Amazon is leading the market with better redundancy and multiple layers of protection to maintain availability.Nevertheless, it is worth noting that AWS isn’t perfect. Relying entirely on the robustness of AWS and its services isn’t the way to create a reliable and robust cloud ecosystem. You still need to configure the different instances correctly and use services to strengthen your system from the core. Fortunately, there are a number of things you can do.
Fault tolerance in cloud computing is a lot like the balance of your car. You can still drive the car—with limitations, of course—if one of the tires is punctured. A fault-tolerant system can do the same thing. Even when one or some of its components stop working due to an error, the system can still deliver its functions or services to a certain extent.Designing a system for maximum fault tolerance isn’t always easy, but AWS offers a number of tools that can be used to boost reliability, starting with AMI. When you begin setting up the system by creating an AMI that works, you have the option to start a new instance using the same AMI should another fail.Another way to add fault tolerance is by using EBS or Elastic Block Storage. Problems associated with your drives running out of storage space can be effectively mitigated using EBS. The use of EBS also allows you to attach different EC2 instances, meaning you can switch from a failing EC2 instance to another without switching storage.Since all configurations and data are stored in the same EBS, you are basically keeping the system running, despite replacing the EC2 instance used by the system. You can take this a step further by introducing Elastic IP address, which allows for multiple EC2 instances to use the same IP address; this eliminates the need for DNS zone updates or reconfiguration of your load-balancing node.
One more thing to note about fault tolerance and redundancy in AWS: you have plenty of auto-scale options to utilize. Many AWS services can now be scaled up (or down) automatically. The others support scaling when triggered.Combined with services like EBS, you can create a fault-tolerant system rather easily in AWS. Adding multiple redundancies to further support the system will result in a capable and immensely reliable system.With the market being as competitive as it is today, offering highly available services to users becomes an important competitive advantage. Downtime is unacceptable; not when your competitors are always available. Increasing fault tolerance and adding redundancies are how you stay ahead of the market. For more on optimizing your cloud ecosystem on AWS read our article Optimizing DevOps and the AWS Well-Architected Framework. Ibexlabs is an experienced DevOps & Managed Services provider and an AWS consulting partner. Our AWS Certified DevOps consultancy team evaluates your infrastructure and make recommendations based on your individual business or personal requirements. Contact us today and set up a free consultation to discuss a custom-built solution tailored just for you.