As more businesses move their IT infrastructure to the cloud, even the best cloud servers are becoming increasingly vulnerable to query overload issues. With bots now initiating 56% of all Internet traffic, databases crashes are becoming more common, which can cause major disruptions if your team depends on your cloud deployment for computing tasks and business processes.
For businesses with consumer-facing apps and websites, downtimes can result in frustrations, especially with today’s culture of on-demand service and instant gratification. Cloud-based digital services are expected to be available 24/7, and a user who sees an error message on your product’s front end might never come back. Even extra slow loading times will discourage visitors, who would simply leave and go back to Google to search for your competitors.
For businesses with distributed server infrastructure – private cloud and hybrid cloud setup alike – load balancing is considered a backbone of the Internet, as this technology maintains a manageable distribution of load across resources. Some public cloud providers and hosting services already come equipped with load balancing solutions included, but once your business scales to a certain extent, a simple DNS-based solution might no longer be adequate.
Load Balancing Explained
Load balancing prevents overloading by regulating traffic and distributing it across servers, thereby allowing you to scale without preventing server overload. A good load balancing solution can detect query spikes before they cause outages, allowing you to eliminate latency and downtime by routing traffic away from servers that are deemed to be in danger of failing.
In terms of the bigger picture, load balancing also allows a company to have balance between stability and features, as well as performance and cost. E-commerce giant eBay comes to mind as a good example here. The company prefers scaling out its architecture instead of scaling up, and implements load balancing across its distributed infrastructure in order to strike that right balance between performance and cost in its database, application and operations architectures. According to the company, this enables seamless growth, quality functionality (at accelerating rates), as well as rapid business innovation.
There are three primary models of load balancing solutions to choose from: those that run from dedicated hardware, those that run as management programs on servers, and those that run straight from the cloud.
Appliance-Based Load Balancing
Appliance-based load balancers are devices dedicated to the task of balancing network traffic loads.
Hardware balancers typically support relatively rich set of features, and they offer more control than the other options. In addition, hardware offloading leads to greater scalability. On the other hand, the main disadvantage of load balancing appliances is that they are expensive, with a reasonably-featured device costing upwards of $60,000.
In addition, appliances are limited to on-premises deployments, which means that these cannot solely be used when a distributed computing or web infrastructure already involves multiple locations, which will require a different approach.
DNS-Based Load Balancing
Software-driven balancers reside on servers and can represent major cost savings, as they are inexpensive and sometimes even free. Software solutions provide DNS-based load balancing without the need to purchase any dedicated hardware, and setup is typically fairly fast.
The main disadvantage of this approach is that it takes time for any changes to to propagate across the various DNS caching servers worldwide, and this could result in uneven performance and delayed responsiveness. Moreover, DNS load distribution solutions rely heavily on randomized algorithms, which generally considered less effective – compared to the intelligent options offered by cloud and appliance-based alternatives. Therefore, a purely DNS-based approach is not reliable nor is it agile.
Source: https://www.incapsula.com/load-balancing-failover.html
DNS is especially unreliable in failover scenarios, where the existence of DNS cache could keep some ISP routing traffic to a downed server, causing partial traffic loss for a significant periods of time.
Cloud-Based Load Balancing
Cloud-based load balancing solutions reside on platforms managed by the load balancing service provider. As these are packaged in a Platform-as-a-Service deployment, this will not affect your own hardware or cloud servers at all, and are both scalable and cost-efficient.
The only drawback to this approach will be for larger enterprises that need to retain full control over their deployment, which are likely to prefer an on-premises hardware-based solution. However, even with an appliance, an organization will require a separate DNS-based load balancer once its distributed infrastructure spans several locations.
How to Choose
Consider your needs, the availability of IT resources in your company and, of course, your budget. A software-based approach is likely to be the least expensive, but an appliance will provide the most control for larger enterprises. The cloud-based load balancing approach is bound to be the most scalable and cost-effective among the three.
It provides a lower barrier to entry compared with an appliance, but without being limited in capability than either the DNS-based or on-premises approach. Because the platform is managed by a solutions provider, your enterprise gains the ability to focus on your core business, rather than get bogged down by unnecessary maintenance and manpower costs.
