CDNs vs Load Balancers: The Content Delivery Dream Team?

Digital transformations have been a top priority for businesses for several years now. And this means more services than ever will be delivered to users via your network solutions, both for internal activities and interactions with customers.

For example, Forrester forecast that in 2021, digital customer service interactions will increase by 40%. Meanwhile, web channels are a vital sales avenue for retailers, while many firms now need to cope with a growing trend toward remote and hybrid working that means employees need to access resources from outside the office.

The need for solutions to support your data network

What this means is content delivery needs to play a vital role in your networking strategy. If employees and customers have to put up with slow services or extended periods of downtime, it's bad news all around. Workers will be frustrated and potential customers will take their business elsewhere.

So how can you ensure your content and services are getting to where they need to be? There are two key options to be aware of to achieve this - content delivery networks (CDNs) and load balancers.

Both of these perform similar roles - to facilitate the delivery of data between servers and end-users. However, they operate very differently and so shouldn't be thought of as interchangeable.

You also can't treat it as a case of CDNs v load balancers. The two aren't in competition, but rather can be used as two elements of a comprehensive content delivery solution. To make the most of these technologies, you'll need to know when is the most appropriate time to use each, and when they can be used in tandem.

The pros and cons of a CDN

CDNs consist of a network of servers that are spread across a wide geographic area. The primary aim is to ensure that when a user requests content, it can be delivered from a server that's physically as close to them as possible, thereby reducing loading times.

The greater the distance data has to travel, the more routers and repeaters it has to go through, each one of which can introduce further delay, making the wide physical distribution of servers a key benefit of CDNs. However, faster response times aren’t the only advantage.

Because data is hosted across multiple servers, this ensures greater redundancy and reliability for the network. If one server does experience downtime, other servers will still be able to deliver content. Similarly, if a server suffers a distributed denial of service attack, a CDN may be able to mitigate the damage by redistributing this.

These networks can also be used to avoid any access restrictions that could prevent people in certain territories from viewing your content.

However, there are a few drawbacks to consider. CDNs can be costly, especially if you want a true global reach and are adopting a multi-CDN strategy. As they’re typically managed by third-party vendors, you'll need to ensure the right level of support is available. And in the unlikely event the network does fail completely, the consequences can be severe, as was seen in the recent Fastly outage.

The pros and cons of load balancers

Load balancers are designed to distribute inbound traffic across a group of servers, thereby reducing the overall pressure on any one. Unlike CDNs, which focus on a wide geographical spread, the servers managed by load balancers are usually within the same data center.

These solutions are therefore highly useful when you're expecting a large volume of users to be accessing your network simultaneously. When many individuals are attempting to access a single server concurrently, they’ll often have to wait their turn. This can lead to long delays - especially if the server is hosting large data files such as videos and images. Load balancers aim to prevent such slowdowns.

Load balancers also look to make the most efficient use of your data center. Without such solutions, it could be the case that the majority of incoming traffic is directed to one server until it's reached capacity, while others sit idle.

Like CDNs, they can improve uptime by redirecting traffic should one server go down. However, load balancers do require more configuration work to set up and maintain, while if you're using a hardware-based load balancer, this can add additional costs.

The benefits of combining CDNs with load balancers

So, which should you use? The answer depends on what type of traffic you're dealing with, and more often than not, it's 'both'. For any business looking to have a worldwide reach, CDNs are vital in ensuring users across the globe can enjoy the same fast, reliable experience. Load balancers, on the other hand, help ensure that your main data centers won't be overwhelmed by heavy volumes of traffic.

Both CDNs and load balancers help improve the speed and reliability of your network, and by deploying them in tandem, all users can enjoy fast access to applications, no matter where they are or what they're trying to connect to.