When it comes to network and server management, DNS load balancing is a great option that allows for improved server speeds and greater reliability. In today’s time-starved world, there are few things more important than a zippy server!
But what is DNS load balancing and what are the benefits of using this load balancing strategy?
What is DNS Load Balancing?
DNS load balancing is a form of automated software-driven server maintenance, designed to break up “clumps” of network traffic and spread it across multiple servers. This is done in an attempt to prevent any single server from getting bogged down and overloaded.
Load balancing is achieved using a specific algorithm in a software program that is installed on a server. DNS load balancing is just one of many algorithms. Alternative load balancing algorithms include the following.
- Geographic load balancing
- Resource based, such as CPU load
- Resource-based load balancing
- Round robin load balancing
- Least connection load balancing
- Fixed weighting load balancing
- Hash-based load balancing
DNS load balancing is unique in that it automatically configures a domain within the domain name system (DNS). You can think of DNS as the internet’s phone book, whereas a domain (or IP address) is akin to a phone number. A domain may be associated with a server, website or any other internet-accessible resource.
In the DNS server load balancing process, the system has multiple IP addresses for a single domain. These IP addresses are sent out in a different order as network requests come in from a new client. This means that traffic is spread across multiple servers, effectively balancing the load — at least, in theory.
Problems can arise if the system does not have a method for detecting network outages or downed servers. This can result in a situation where the DNS load balancer sends traffic to an overloaded or inaccessible IP address. For this reason, it is prudent to seek DNS software with a mechanism for identifying and avoiding these problem areas.
Improved Speed as a DNS Load Balancing Benefit
DNS load balancing allows for faster speeds since the client is provided with multiple IP addresses for a single domain. This sends traffic to multiple servers, reducing the incidence of server crashes and server overloads. The latter results in slow load times and ultimately, a rather negative user experience.
Improved server performance is a major advantage because it is one of the most noticeable user-experience issues that an individual might encounter.
Improved Reliability as a Benefit of DNS Load Balancing
There is a good reason that DNS load balancing is considered a preferred method and best practice for mission-critical technology. This server load balancing method is exceptionally reliable. What’s more, DNS queries represent relatively simple UDP connections that allow for easy deployment. But beyond this, it is common practice to monitor for “unhealthy” and consistently troublesome DNS servers. Once identified, these servers are rapidly removed from the list of available servers used for client query requests.
DNS server load balancing delivers improved reliability in other ways too. The very act of load balancing effectively reduces the chance of a server crash. Crashed servers take time to restore, leading to potentially significant periods of downtime in the worst cases.
Better reliability also arises from the use of multiple IP addresses for a single domain. You can think of it a bit like having multiple doors that allow you to enter a room. If one of those doors is locked, you simply use a different door. If there’s just one door leading into the room and it’s locked, then you’re out of luck and unable to access the room.
Notably, the very architecture of a DNS load balancing system promotes strong reliability and uptime. The reason? The use of multiple DNS servers makes it possible to remove a single one from service to perform maintenance or repairs, while the remaining are left to handle the incoming requests.
Improved Scalability With DNS Load Balancing
DNS load balancing allows for a high degree of scalability — far beyond what can be achieved with other load balancing methods. A single external IP address accommodates multiple servers and it’s possible to add more services in a dynamic manner as the need arises. This makes scaling simple and straightforward.
The Flexibility in DNS Load Balancing Methods
DNS server load balancing is actually rather flexible — a quality that provides an advantage to those who are tasked with network management. There are several methods that can be used to distribute or redirect the requests from incoming traffic.
Round Robin DNS-based Load Sharing – Round Robin is a common server load balancing algorithm, but it can be used in conjunction with DNS load balancing too. Using this approach, incoming DNS requests are distributed across several different server instances. The algorithm automatically changes up the order for distribution, preventing an overload on any single server.
Dynamic DNS Server Load Balancing – With dynamic DNS load balancing, incoming DNS requests are dynamically distributed to the servers that are capable of the fastest speeds and most available resources. This translates into improved performance.
Using Backup Servers With DNS Load Balancing – In cases where redundancy is necessary for a mission-critical application, use of a backup server can be used in conjunction with DNS load balancers. A domain clone is created to serve as a secondary DNS instance and if the need arises, the primary DNS can send incoming requests to this secondary backup at runtime.
These three approaches can be very effective for devising a custom DNS server load balancing strategy, especially in cases of mission-critical technology that demands maximum reliability and constant uptime.
DNS load balancing brings many potential benefits, but you need a partner who can effectively deploy that technology. To learn more about today’s cutting-edge DNS load balancing solutions, turn to the experts at Resonate. We are regarded as industry-leading experts in load balancing software solutions. Contact Resonate to learn more about how our load balancing technology can benefit your organization and its operations.