What is a Load Balancer and how does Load Balancer work?
It is the method of distributing network or application traffic across multiple hosts in a server farm described in detail below. Load balancers are devices that sit between clients and backend servers, taking user requests and allocating them to the available servers.
Load balancing spreads network traffic over different servers. This ensures no server gets overloaded. Supporting load balancing increases application performance. It also makes apps and websites more accessible to users. Load balancers are essential for modern apps. Software load balancers have evolved to provide application security.
Load balancers can be used to:
- A digitized version running on a single device or software, whether physical or virtual.
- Web and network system applications built on a three-tier architecture can benefit from application delivery controllers, which are meant to improve reliability and speed.
- When distributing traffic according to current needs, a variety of load balancing strategies can be utilized to achieve the best results.
How does load balancer work?
When a load balancer is used instead of an application delivery controller, which has more functions, it operates as the front-end to an array of web servers. All incoming HTTP requests from clients are resolved to the load balancer’s IP address. Once the request is received, the load balancer routes it to one of its list of web servers in what amounts to a private cloud.
Load-balancing software relays server responses to clients using a server-to-client load balancer.
There’s only one endpoint for clients to talk to; therefore, load balancing is transparent to them and solves a variety of service issues:
You only need to add more web servers to the load balancer’s roster to see a performance improvement.
For whatever reason, high-availability load-balancing identifies the interruption and stops forwarding requests to that server.
Back-end servers that require maintenance or updates are simply deleted from the load balancer’s list.
During the advancement of this technology, the load balancer was “hardened” to safeguard the web servers it administers. The possible risks that complex online programs can introduce are a vital requirement for servers running web applications.
Common load balancing algorithms
A load balancer will send requests throughout the server farm based on an algorithm that is developed. There are many options here, from simple to complex.
1. Round robin
Each client request will be routed to a separate digital server based on a rotating list that has used round-robin. However, when implementing load balancers, it does not take into account the loading on a server. If a server receives an abnormally large number of requests that require a large amount of processing power, it may become overloaded.
2. Lowest Common Denominator Method
The least connection considers a server’s current load, and as a result, it typically provides better results. Using the simplest connection approach, requests will be sent to the virtual server that is least busy.
3. Minimal Reaction Time Method
Based on the time it takes a server to request authorization to monitor systems. Response time measures loading speed and user experience. Others will show the number of concurrent users on each server.
4. The least amount of bandwidth
This algorithm looks for the server that currently serves less traffic, measured in Mbps.
5. Minimum Packets
This technique examines the number of packets received to determine which service has had the fewest packets received in a given period.
6. Hashing Techniques
This segment uses hashed data from the incoming request to make decisions. Included in the incoming packet are connection details, such as reference IP address and port number.
7. Custom Load Method
Individual servers can be queried via SNMP using the custom load method. An administrator can define the server load they are interested in querying – Processor speed, memory usage, and speed of response, and merge them to meet their needs.
Why is Load Balancer Required?
Load-balancing can help IT teams assure service availability and scalability. The advanced traffic management capabilities can successfully route requests to the appropriate resources for each end-user. Load-balancing secures, manages, and monitors software and services through infrastructures, ensuring the best end-user performance.