Elastic Load Balancing
Achieve fault tolerance for any application by ensuring scalability, performance, and security.
Elastic Load Balancing automatically distributes incoming application traffic across multiple targets, such as Amazon EC2 instances, containers, IP addresses, and Lambda functions. It can handle the varying load of your application traffic in a single Availability Zone or across multiple Availability Zones. Elastic Load Balancing offers three types of load balancers that all feature the high availability, automatic scaling, and robust security necessary to make your applications fault tolerant.
Application Load Balancer
Application Load Balancer is best suited for load balancing of HTTP and HTTPS traffic and provides advanced request routing targeted at the delivery of modern application architectures, including microservices and containers. Operating at the individual request level (Layer 7), Application Load Balancer routes traffic to targets within Amazon Virtual Private Cloud (Amazon VPC) based on the content of the request.
Network Load Balancer
Network Load Balancer is best suited for load balancing of Transmission Control Protocol (TCP), User Datagram Protocol (UDP) and Transport Layer Security (TLS) traffic where extreme performance is required. Operating at the connection level (Layer 4), Network Load Balancer routes traffic to targets within Amazon Virtual Private Cloud (Amazon VPC) and is capable of handling millions of requests per second while maintaining ultra-low latencies. Network Load Balancer is also optimized to handle sudden and volatile traffic patterns.
Classic Load Balancer
Classic Load Balancer provides basic load balancing across multiple Amazon EC2 instances and operates at both the request level and connection level. Classic Load Balancer is intended for applications that were built within the EC2-Classic network.
Elastic Load Balancing automatically distributes incoming traffic across multiple targets – Amazon EC2 instances, containers, IP addresses, and Lambda functions – in multiple Availability Zones and ensures only healthy targets receive traffic. Elastic Load Balancing can also load balance across a Region, routing traffic to healthy targets in different Availability Zones. The Amazon Elastic Load Balancing Service Level Agreement commitment is 99.99% availability for a load balancer.
Elastic Load Balancing works with Amazon Virtual Private Cloud (VPC) to provide robust security features, including integrated certificate management, user-authentication, and SSL/TLS decryption. Together, they give you the flexibility to centrally manage TLS settings and offload CPU intensive workloads from your applications.
Elastic Load Balancing is capable of handling rapid changes in network traffic patterns. Additionally, deep integration with Auto Scaling ensures sufficient application capacity to meet varying levels of application load without requiring manual intervention.
Elastic Load Balancing also allows you to use IP addresses to route requests to application targets. This offers you flexibility in how you virtualize your application targets, allowing you to host more applications on the same instance. This also enables these applications to have individual security groups and use the same network port to further simplify inter-application communication in microservice-based architecture.
Robust monitoring & auditing
Elastic Load Balancing allows you to monitor your applications and their performance in real time with Amazon CloudWatch metrics, logging, and request tracing. This improves visibility into the behavior of your applications, uncovering issues and identifying performance bottlenecks in your application stack at the granularity of an individual request.
Hybrid load balancing
Elastic Load Balancing offers ability to load balance across AWS and on-premises resources using the same load balancer. This makes it easy for you to migrate, burst, or failover on-premises applications to the cloud.
Achieve better fault tolerance for your applications
Elastic Load Balancing provides fault tolerance for your applications by automatically balancing traffic across targets – Amazon EC2 instances, containers, IP addresses, and Lambda functions – in multiple Availability Zones while ensuring only healthy targets receive traffic. If all of your targets in a single Availability Zone are unhealthy, Elastic Load Balancing will route traffic to healthy targets in other Availability Zones. Once targets have returned to a healthy state, load balancing will automatically resume to the original targets.
Automatically load balance your containerized applications
With enhanced container support for Elastic Load Balancing, you can now load balance across multiple ports on the same Amazon EC2 instance. You can also take advantage of deep integration with the Amazon EC2 Container Service (ECS), which provides a fully-managed container offering. Simply register a service with a load balancer, and ECS transparently manages the registration and de-registration of Docker containers. The load balancer automatically detects the port and dynamically reconfigures itself.
Automatically scale your applications
Elastic Load Balancing provides confidence that your applications will scale to the demands of your customers. With the ability to trigger Auto Scaling for your Amazon EC2 instance fleet when latency of any one of your EC2 instances exceeds a preconfigured threshold, your applications will always be ready to serve the next customer request.
Using Elastic Load Balancing in your Amazon Virtual Private Cloud (Amazon VPC)
Elastic Load Balancing makes it easy to create an internet-facing entry point into your VPC or to route request traffic between tiers of your application within your VPC. You can assign security groups to your load balancer to control which ports are open to a list of allowed sources. Because Elastic Load Balancing is integrated with your VPC, all of your existing Network Access Control Lists (ACLs) and Routing Tables continue to provide additional network controls.
When you create a load balancer in your VPC, you can specify whether the load balancer is internet-facing (default) or internal. If you select internal, you do not need to have an internet gateway to reach the load balancer, and the private IP addresses of the load balancer will be used in the load balancer’s DNS record.
Hybrid load balancing with Elastic Load Balancing
Elastic Load Balancing offers ability to load balance across AWS and on-premises resources using the same load balancer. For example, if you need to distribute application traffic across both AWS and on-premises resources, you can achieve this by registering all the resources to the same target group and associating the target group with a load balancer. Alternatively, you can use DNS-based weighted load balancing across AWS and on-premises resources using two load balancers, with one load balancer for AWS and other for on-premises resources.
You can also use hybrid load balancing to benefit separate applications where one is in a VPC and the other is in an on-premises location. Simply put the VPC targets in one target group and the on-premises targets in another target group, and then use content based routing to route traffic to each target group.
Invoking Lambda functions over HTTP(S)
Elastic Load Balancing supports invoking Lambda functions to serve HTTP(S) requests. This enables users to access serverless applications from any HTTP client, including web browsers. You can register Lambda functions as targets and leverage the support for content-based routing rules in Application Load Balancers to route requests to different Lambda functions. You can use an Application Load Balancer as a common HTTP endpoint for applications that use servers and serverless computing. You can build an entire website using Lambda functions or combine EC2 instances, containers, on-premises servers and Lambda functions to build applications.
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