Multi-application or dedicated load balancing – which approach is best?

With a big, powerful and expensive ADC load balancer, there can be a strong temptation to load balance multiple applications – but when uptime is critical, could it become a single point of failure?

The global pandemic has dramatically changed the way organizations in all sectors and regions do business – accelerating the adoption of digital technologies by several years and redefining how we work, learn, shop, access services, and interact with each other. While the consumer adoption of telehealth in the US increased from 11 percent in 2019 to 46 percent in April last year, the concept of homeworking also skyrocketed, rising from 6% of all employees pre-pandemic, to 43% in April this year – placing a strain on many IT infrastructures, with users reporting slow application response times and downtime.

At the same time, consumers increased their online shopping, began streaming more online entertainment services and turned to video to maintain contact with family and friends. Application usage soared, as did users’ expectations for 24/7 services, yet IT teams had little or no access to their data centers.  

The organizations that coped best in these extraordinary circumstances were those that prepared for a worst case scenario, expecting it never to happen. They had load balancers in place, capable of managing the unprecedented surge in application traffic and maintaining uninterrupted services by working behind the scenes to keep vital collaboration tools, ecommerce platforms and communications services available for an unprecedented numbers of users.

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As a fundamental component in your application delivery architecture, load balancers play a critical role in these uncertain times – helping organizations big and small achieve guaranteed application uptime. Load balancing maximizes application efficiency and resiliency, reduces future infrastructure spend, and most importantly, ensures high uptime and system performance – but, depending on individual business requirements, organizations can choose to invest in:

• multi-application load balancing or,
• per-application load balancing (aka dedicated load balancing)

But which one is best for your organization?

Multi-application load balancing

Multi-application load balancing can be a good option for very large enterprises. It involves using a single load balancer appliance or platform to balance the traffic for all or multiple applications within an organization. Such solutions can be heavily customized to handle the traffic for different applications in different ways. Besides, they often come with an array of supplementary features, such as added security. But as more and more applications are added to large load balancer platforms, with more customizations being made, the application delivery environment can get a lot more complex. Therefore, organizations using this type of load balancing need to make sure that they have the specialist IT skills in-house to manage and maintain the solution.

Per-application load balancing

The alternative approach is per-application load balancing – a flexible and resilient solution. Here, a dedicated load balancer (or a pair of dedicated load balancers) are used with each individual application. These are simple-to-use products that come with advanced, intelligent load balancing capabilities to route and reroute traffic in a fraction of a second to deliver exceptional user experiences. The load balancing solution can be tuned specifically to ensure the high availability of the priority application, without having to take the needs of other applications into account – so this approach is particularly recommended for mission-critical applications, when downtime isn’t an option.

Dedicated solutions are often easier to configure, manage and maintain – making them less likely to be compromised by human error. And although, it was at one time cost-prohibitive to have dedicated load balancers for each application, now, with the reduced cost of hardware – as well as the emergence of virtual and cloud-based load balancers – the per-application approach is a very viable option. For organizations that need to standardize on single-vendor solutions to meet company policies and keep their IT estate simple, they can buy multiple load balancers from the same vendor and configure a pair to support each critical application.

Has ADC automation changed anything?

The last few years have seen a massive growth in the use of automation for load balancing workloads. Complex on-site solutions such as AppViewX with ADC+, have made the maintenace of complex multi-app load balancers such as F5 much easier.
In contrast software as a servicew based solutions such as the Kemp Loadmaster 360 and the Loadbalancer ADC Portal focus on the per application approach.

So, which is best?

Load balancers have been around for many years now, and the challenges that businesses have faced during recent uncertain times have made CIOs and IT leaders rethink the importance of load balancing in a more meaningful way.

Consequently, as more and more organizations are changing the way they look at load balancing and prioritizing it as a crucial IT investment, both the multi-application and per-application approaches are evolving, in response to new business needs and concerns.

The traditional multi-application approach can have some of the negatives reduced through the careful use of automation.

However the per-application load balancing approach has continued to gain in popularity and is gaining pace with strong vendor support.  When combined with application centric approaches to automation,  I feel this is the most logical way to get one step closer to the goal of zero downtime.

Learn more: for more on approaches to load balancing, download our free ebook, which includes technical examples and customer use cases: