Public vs internal load Balancers


In the fastpaced environment of web applications user experience and speed are at an alltime high This is where load balancers come in working behind the scenes to make hightraffic websites and applications run smoothly As network architectures grow more complex the question of which type of load balancer to use arises public or internal Knowing the difference is important when you are making decisions about your applications infrastructure.

 The Balancing Act: What Does a Load Balancer Do

Imagine a busy restaurant with only one waiter When additional customers show up frustration mounts as the waiters tasks pile up A load balancer is in a sense just like hiring more waiters or bringing servers into the restaurant It helps improve user experience by spreading incoming internet traffic among multiple servers

In the digital world a load balancer distributes incoming network traffic across multiple servers in a pool This architecture helps prevent a single server from becoming overwhelmed which speeds up response times and increases user satisfaction And this is where the distinction between public and internal comes into play

 The Public Load Balancer: Your Gateway to the World

A public load balancer is the entry point to your application from the internet. It has a public IP address that allows users to connect from around the globe. This is how it works

  • Public IP Address: The public load balancer has a public IP to receive all incoming internet traffic

  • Traffic Distribution: Incoming traffic from the internet is received by the public load balancer

  • Server Selection: The load balancer selects the suitable server from the pool based on a predefined algorithm, eg, round robin least connections

  • Traffic Forwarding: The server selected in the previous step receives the forwarded request and serves it

  • Response Delivery: The response from the server is routed back to the user via the load balancer

Public load balancers are used for applications that are available on the internet and can be accessed from anywhere, for example:

  • E-commerce websites: Used to facilitate smooth transactions for a broad set of users

  • Content Delivery Networks: CDNs Used to disseminate static content such as images or videos across multiple servers in different locations to speed up the download process

  • Web applications: Used to balance traffic for a user base that is worldwide

Internal Load Balancer: Keeps Balancing Behind the Scenes

An internal load balancer, as the name suggests, works within your private network and not on the public internet. It has a private IP address not visible to the public. Here is how it works:

  • Private IP Address: It resides in your Virtual Private Cloud VPC with a private IP address internet traffic cannot reach it.

  • Internal Traffic: Management It manages the internal applications or traffic in your network and routes it to different servers within your network.

  • Enhanced Scalability: As the traffic reaches a certain level, it helps to add more servers to the pool for horizontal scaling.

  • Availability: When one server fails, traffic is automatically distributed to another healthy server by the load balancer.

Internal load balancers work well for applications running within a private network such as:

  • Microservices architectures: Used to balance traffic between multiple microservices in a complex application

  • Database clusters: Used to distribute database queries across multiple database servers

  • Internal APIs: Balancing traffic for APIs used within your organization

 Selecting the Right Load Balancer: A Compromise

The decision on whether to use a public or internal load balancer depends on your specific applications' nature and access settings, Let's start with a brief:

  • Public Load Balancer: Good for applications available over the internet that require a publicfacing entry point

  • Internal Load Balancer: This is best for applications hosted internally and not exposed to the internet

 The Power of Coexistence and Collaboration

Many organizations make use of both public and internal load balancers in their infrastructure. The following explains how they can complement each other:

  •  Public Load Balancer: Routes traffic from external sources to the application.

  • Internal Load Balancer: Routes traffic within the application hidden behind a firewall, which offers an increased level of security.

 Conclusion

Both public and internal load balancers are essential parts of a modern web infrastructure Understanding how they work and selecting the right one is key to building scalable reliable fast applications So the next time you experience a seamless quick online experience remember the unsung hero in the background the load balancer who works away diligently to ensure traffic is efficiently distributed and user journey is kept smooth.