System Design on AWS - Load Balancer

Load Balancer in system design on AWS plays an crucial role by distributing and balancing incoming traffic across multiple targets, such as Amazon EC2 instances, in one or more Availability Zones. This allows for high availability, scalability, and reliability of applications.

Load Balancer Types In AWS

There are several types of load balancers available on AWS, including:

• Application load balancing: Application Load Balancers operate at the application layer. This Load Balancing helps direct traffic to the right server by looking at the details of each request, like HTTP headers or SSL session IDs ensuring traffic reaches the correct server and ensuring everything runs smoothly and efficiently.
• Network load balancing: Network Load Balancers operates at the transport layer. Network Load Balancers direct traffic by looking at IP addresses and network info. They track traffic sources and can assign one IP address to multiple servers, using algorithms to balance server load.
• Global server load balancing: Global Server Load Balancing directs traffic to servers across different locations. It sends traffic to the closest server, unless a server fails, then it redirects to another one.
• DNS load balancing: DNS Load Balancing directs users to multiple IP addresses for a single domain, improving application availability and performance. It works by returning different IP addresses each time the domain is requested, allowing traffic to be distributed across multiple servers.

How Load Balancers Work on AWS?

Here's a simple overview of how load balancers work on AWS:

• Companies run their applications on multiple servers, known as a server farm.
• A client sends a request to the load balancer.
• Then, load balancer selects the best server from the server farm.
• The load balancer performs health checks on the server to ensure they are available and functioning correctly.
• The load balancer directs each request to the best server in the farm to handle it.

Functions of Load Balancers

The following are the functionality of Load Balancers in system design on AWS:

• Distributing Traffic: Load Balancers distributes incoming traffic across multiple targets, such as EC2 instances, containers, and IP addresses, in one or more Availability Zones.
• Monitoring Health: Load Balancers monitors the health of their targets in order to check if their targets are healthy they will only send traffic to those targets that are working well.
• Integrates With SSl: The load balancer can handle Secure Sockets Layer (SSL) or Transport Layer Security (TLS) connections. It decrypts incoming SSL/TLS traffic and sends it to backend servers, ensuring secure communication and efficient traffic management.
• Elastic: This is the functionality of load balancer that it will scale itself based on the growing traffic.

Load Balancers Importance

Load balancers play a crucial role in system design on AWS are as follows:

• Increased Fault Tolerance: Load balancers detect server issues and redirect traffic to working servers, ensuring high availability and reducing downtime.
• Improved Scalability: Load balancers distribute traffic across multiple servers, enabling systems to scale efficiently and handle more traffic. This ensures that no single server is overwhelmed, leading to better performance.
• Enhanced Security: Load balancers help protect systems from cyber attacks by distributing traffic and hiding internal IP addresses. This adds an extra layer of security, making it harder for attackers to target specific servers.
• Better Resource Utilizations: Load balancers ensure that no single server is overwhelmed, leading to efficient use of resources and lower costs. This helps systems run smoothly and saves money.
• Improved User Experience: Load balancers direct traffic to healthy targets, ensuring users experience minimal errors and fast response times. This leads to a smoother and more reliable online experience.

Challenges of Load Balancers

Load Balancers also deal with some Challenges that have to be kept in mind to avoid them while designing systems on AWS

• Handling high traffic and large data volumes
• Managing user sessions and server loads
• Distributing traffic efficiently
• Handling server failures
• Preventing overload and crashes
• Providing high availability