A server load balancer plays an important role in distributing traffic across numerous processing resources. Load balancing is essential in keeping a website or application operational without suffering crashes due to an overload of users. The main goal of a load balancer is to optimize the end-user experience by ensuring that the traffic is spread out across servers for the best results. When evaluating load balancing solutions, the options can get a little overwhelming, which is why we are providing an overview on what factors to consider.
Options Available
Not all load balancers are created equal. From hardware to software, layer 4 to layer 7, you have some options:
• Hardware vs. Software
Hardware load balancers are physical devices that are typically loaded with proprietary software. They are costly to deploy, have reduced flexibility, and have to be managed by an in-house IT team. Software solutions, on the other hand, can be easily deployed, offer increased flexibility and scalability.
• Layer 4 vs Layer 7
Load balancers typically function at either layer 4 or layer 7 of the OSI model. Load balancers operating at layer 4 (TCP layer) cannot inspect incoming packets. However, this can reduce latency for applications that require end-to-end encryption. Load balancers that operate at layer 7 (application layer) can inspect packets and route traffic based on advanced requirements such as sticky sessions. Load balancers that offer layer 4-7 load balancing offer the ultimate in flexibility.
Algorithms
When considering a load balancer, you’ll also need to be familiar with the algorithms—the different rules for the methods of distributing traffic—that will be available to you. Here are the most common algorithms:
• Resource-Based
The resourve-based approach relies on custom intelligence to measure the resource, (CPU load) from all of the content nodes. Each incoming request is then assigned to the server with the most available resource.
• Least Connection
The least connection method distributes traffic to servers that have the fewest number of active connections. Least connection load balancing focuses on creating a balance while avoiding a server pool from having a significantly larger number of active connections.
• Random Assignment
Random assignment assigns each workload randomly to a group of servers. The main theory behind random assignment balancing is that eventually, each server in the pool will have an equal workload.
• Round Robin
Round robin load balancing is a more balanced approach, as each server pool receives a spot in the overall order of use. Ultimately, round-robin distribution makes sure that each server can handle incoming traffic.
• Source IP Hash
IP hashing distributes the workload solely based on the incoming IP address for each server request, which is more complex than the other server load balancing methods. Each incoming workload is assigned a hash key that is based on the destination and source IP address, which uses this information to handle the incoming workload.
Considering Your Needs
We’ve covered some overall options that are available from load balancers. Here are some key considerations you should evaluate about your business before making your decision.
Evaluate Both Short-Term and Long-Term Needs
Many IT teams looking for a load balancing solution are doing so under pressure. Servers are failing, and site traffic is becoming bottlenecked. However, tempting as it might be to scoop up and implement the first solution you come across, take some time to evaluate your overall strategy. How should network traffic be distributed? What form of failover is needed? Do you, or will you in the future, need encryption? Asking yourself these questions can save you from making a mistake with a stopgap measure.
• Anticipate Future Network Load
On the heels of anticipating long-term or future needs, you’ll also want to conduct an assessment of the growth rate of your traffic. If you select a load balancing solution to meet your current traffic needs, you might under-buy and quickly outgrow your choice. Do you have a peak season coming up? Are you offering new services? Look at factors that could impact traffic.
• Plan for High Availability
Apart from optimizing your server performance and speeding up traffic, one of the main solutions that your load balancer should provide is business continuity through increased availability. By ensuring that your business applications are always available, you increase your company’s efficiency and profitability.
• Address Security Issues
Putting a load balancing solution in place should increase your security, not compromise it. When companies are putting a load balancer in place, they are usually also increasing the number of servers in addition to increasing the amount of traffic that those servers can handle. This translates to more targets for hackers. Just like continuity, security should be another solution that your load balancer provides.
• ROI
When evaluating the ROI for a load balancer, be sure to compare the opportunity cost of lost business against the value that the load balancer brings. Downtime can be estimated, measured, and valued, and weighed against the cost of deploying a load balancing solution.
• Overall Cost of Ownership
When making your decision, you should estimate not only the costs associated with the initial deployment, but also any ongoing expenses such as software upgrades or services.
Investing in the Right Choice
Understanding the various options available for server load balancing is key in helping you find the best solution for your business. Load balancing also gives your company an additional layer of security, and is a fantastic way to reduce downtime and create the best end-user experience available.
Software Load Balancing from Resonate
Resonate is a load balancing software company providing both layer 4-7 and global solutions capable of meeting the needs of a variety of clients. Implementing our solutions is an excellent way to minimize downtime, improve reliability, and also reduce costs for your business. Our team is always available to answer any of your questions you may have. If you would like to discuss how our solutions can be customized to meet the needs of your business, contact us today.