LB's
In order to achieve high availability, fault tolerance, and maximum performance of your applications, load balancers in AWS (Amazon Web Services) are a crucial component for spreading incoming network traffic over several instances (virtual servers).
Application layer load balancer
At the application layer (Layer 7) of the OSI model, an application layer load balancer (ALB) is a type of load balancer used in cloud computing and networking to distribute incoming application traffic among several backend targets, such as EC2 instances, containers, or Lambda functions. Here is a quick rundown of the main characteristics and advantages of an application load balancer:
ALBs operate at the application layer of the OSI model, which enables them to comprehend and make routing decisions based on application-level protocols like HTTP and HTTPS. Layer 7 Load Balancing. Advanced traffic management and content-based routing are made possible by this.
ALBs may route traffic based on the content of HTTP requests, such as the URL path, hostname, headers, and query parameters. This technique is known as content-based routing. This enables Depending on a set of parameters, you may direct requests to various target groups or backend services.
Offloading SSL/TLS: SSL/TLS encryption and decryption may be handled by ALBs, which lessens the computational strain on backend servers. Additionally, they provide HTTPS listeners for managing traffic securely.
Network Load Balancer
At the transport layer (Layer 4) of the OSI model, a network load balancer (NLB) is one of the load balancing options provided by Amazon Web Services (AWS) for distributing network traffic over different targets, such as Amazon Elastic Compute Cloud (EC2) instances, containers, and IP addresses. The main traits and attributes of network load balancers are listed below:
NLBs, which act at the transport layer and make routing decisions based on network-level data like IP addresses and TCP/UDP ports, are used for Layer 4 load balancing. They can effectively handle both TCP and UDP traffic as a result.
High Throughput and Low Latency: NLBs provide low-latency and high-throughput load balancing and are ideal for high-performance applications. Millions of queries may be processed by them each second.
Static IP addresses are made available by NLBs. At the transport layer (Layer 4) of the OSI model, a network load balancer (NLB) is one of the load balancing options provided by Amazon Web Services (AWS) for distributing network traffic over different targets, such as Amazon Elastic Compute Cloud (EC2) instances, containers, and IP addresses. The main traits and attributes of network load balancers are listed below:
NLBs, which act at the transport layer and make routing decisions based on network-level data like IP addresses and TCP/UDP ports, are used for Layer 4 load balancing. They can effectively handle both TCP and UDP traffic as a result.
High Throughput and Low Latency: NLBs provide low-latency and high-throughput load balancing and are ideal for high-performance applications. Millions of queries may be processed by them each second.
Gateway Load Balancer
A Gateway Load Balancer (GWLB) is a type of load balancer service provided by Amazon Web Services (AWS) that is designed to distribute network traffic across multiple virtual appliances, such as firewalls, intrusion detection and prevention systems (IDPS), and other network security or monitoring appliances, in order to enhance the security and high availability of your applications. Here are the key features and characteristics of a Gateway Load Balancer:
Appliance Load Balancing: GWLB is specifically built for routing traffic to a fleet of third-party virtual appliances. These appliances can include security tools, network monitoring solutions, and other network services.
Health Checks: Like other AWS load balancers, GWLB performs health checks on the virtual appliances to ensure they are operational. Traffic is routed only to healthy appliances.
Custom Routing Rules: GWLB allows you to create custom routing rules based on criteria such as source IP address, source port, destination IP address, destination port, and protocol. This enables you to implement complex traffic routing policies.
Static and Dynamic Routing: GWLB supports both static (fixed) and dynamic (BGP) routing, providing flexibility in how you route traffic to your virtual appliances.
Scalability: GWLB is designed to handle large volumes of traffic and can automatically scale to accommodate increased workloads.
Preserve Client IP Addresses: You have the option to preserve the original client IP address when traffic is forwarded to the virtual appliances. This is important for maintaining visibility into the source of network traffic for security and monitoring purposes.
High Availability: GWLB can be configured across multiple Availability Zones (AZs) to ensure high availability and fault tolerance. If one AZ becomes unavailable, traffic is automatically routed to healthy appliances in another AZ.
Integration with AWS Services: GWLB can be integrated with other AWS services like Amazon VPC (Virtual Private Cloud), making it easy to route traffic from your VPC to the virtual appliances.
Logging and Monitoring: GWLB provides logging and monitoring capabilities, including CloudWatch metrics and access logs, to help you track and troubleshoot traffic patterns and performance.
Gateway Load Balancers are particularly useful in scenarios where you want to route network traffic through security appliances or network monitoring tools to inspect and filter the traffic before it reaches your applications. They help enhance the security and visibility of your network while maintaining high availability and scalability.
Please note that as of my last knowledge update in September 2021, Gateway Load Balancer was a relatively new AWS service, and there may have been updates or changes to its features and capabilities since then. It's a good practice to refer to the official AWS documentation for the most up-to-date information on Gateway Load Balancer.