Elastic Load Balancing

Definition of Elastic Load Balancing

Elastic Load Balancing (ELB) is a cloud-based service provided by Amazon Web Services (AWS) that automatically distributes incoming application traffic across multiple target instances, such as virtual machines or servers. This helps to optimize resource usage, reduce response times, and enhance the overall performance and availability of an application. By adjusting to fluctuating traffic volume, ELB ensures a better user experience and prevents server overloads.


The phonetics for “Elastic Load Balancing” using the International Phonetic Alphabet (IPA) are as follows: /ɪˈlæstɪk loʊd ˈbælənsɪŋ/

Key Takeaways

  1. Elastic Load Balancing automatically distributes incoming application traffic across multiple Amazon EC2 instances, improving the availability and fault tolerance of your applications.
  2. It supports three types of load balancers: Application Load Balancer, Network Load Balancer, and Classic Load Balancer, each with unique features optimized for various use cases and protocols.
  3. Elastic Load Balancing offers features such as health checks, SSL/TLS termination, and connection draining to further ensure high availability and security for your applications.

Importance of Elastic Load Balancing

Elastic Load Balancing (ELB) is an important technology term because it plays a crucial role in ensuring high availability, scalability, and reliability of applications deployed in cloud environments.

ELB distributes incoming traffic evenly across multiple servers, thus optimizing resource use while preventing any single server from becoming a potential bottleneck or point of failure.

By dynamically adjusting to changes in traffic patterns and server health, ELB helps maintain a seamless user experience, minimizes response times, and allows for better handling of peaks in demand.

Furthermore, it supports advanced features such as SSL/TLS termination and advanced routing, further enhancing the security and effectiveness of web-based services.

Overall, Elastic Load Balancing is a vital tool for businesses seeking to maintain high-performance applications in the ever-evolving world of cloud computing.


Elastic Load Balancing (ELB) is an essential component in a robust and scalable infrastructure, designed to distribute incoming network traffic across multiple servers or instances efficiently. The primary purpose of ELB is to ensure smooth operation and minimize downtimes by preventing an overload of any single server.

This technology enables administrators to distribute workloads evenly, thus managing overall system performance and ensuring optimal resource utilization. By automatically adjusting to fluctuations in the volume of traffic and the availability of resources, ELB expedites applications’ response time, improves fault tolerance, and maintains the user experience at an elevated level.

Furthermore, Elastic Load Balancing’s intelligence allows it to assess the health of the servers in the pool and route traffic only to the healthy instances, swiftly removing any unhealthy ones from the equation. This process ensures seamless operation for end users, even during maintenance or server failure events.

ELB also offers flexibility in terms of supporting various traffic routing algorithms, allowing administrators to tailor the traffic distribution strategy suited to their unique requirements. Overall, Elastic Load Balancing is a vital service that enables businesses to maintain high availability, scalability and a resilient system architecture, while continually meeting the growing demands of their end-users.

Examples of Elastic Load Balancing

Elastic Load Balancing (ELB) is a technology offered by Amazon Web Services (AWS) that distributes network traffic across multiple servers to ensure consistent application performance and availability. Here are three real-world examples of organizations utilizing ELB for their technology infrastructure:

Netflix:Netflix, a popular streaming service, relies heavily on ELB to manage its massive traffic numbers and maintain excellent user experience. Elastic Load Balancing helps distribute streaming requests among various servers, reducing latency issues and preventing server overloads. This ensures smooth content streaming and seamless browsing experiences for millions of Netflix users worldwide.

Airbnb:Airbnb, a leading vacation rental platform, uses AWS services, including Elastic Load Balancing, to manage traffic for its web applications efficiently. ELB allows Airbnb to distribute incoming traffic to multiple servers, maintaining high availability and ensuring a robust user experience. As Airbnb continues to grow, the scalability provided by ELB helps maintain the platform’s performance even as traffic increases.

Expedia:Expedia, a leading online travel agency, relies on Elastic Load Balancing to manage its vast web traffic for millions of customers seeking travel services. ELB helps distribute incoming traffic to multiple servers, ensuring smooth performance even during peak times. By utilizing ELB, Expedia can maintain uninterrupted service and excellent user experiences for customers looking for flights, hotels, and other travel-related services.

Elastic Load Balancing FAQ

What is Elastic Load Balancing?

Elastic Load Balancing (ELB) is a load balancing service provided by Amazon Web Services (AWS) that allows for the automatic distribution of incoming application traffic across multiple Amazon EC2 instances. It improves the availability and fault tolerance of your applications.

What are the different types of Elastic Load Balancers?

There are three types of Elastic Load Balancers provided by AWS: Application Load Balancer (ALB), Network Load Balancer (NLB), and Classic Load Balancer (CLB).

What is the difference between an Application Load Balancer and a Network Load Balancer?

An Application Load Balancer (ALB) operates at the request level (layer 7 of the OSI model) and is best suited for load balancing HTTP/HTTPS traffic. It provides advanced routing features like path and host-based routing. A Network Load Balancer (NLB), on the other hand, operates at the connection level (layer 4 of the OSI model) and is best suited for load balancing TCP, UDP, and TLS traffic. It is mainly used for high-performance applications and when low latency is required.

How can I set up Elastic Load Balancing?

To set up Elastic Load Balancing, you need to do the following steps: 1) Create an Elastic Load Balancer, 2) Specify the instances to be added to the load balancer, 3) Configure your load balancer settings, 4) Set up health checks, and 5) Configure a security group for your load balancer.

How does Elastic Load Balancing handle unhealthy instances?

Elastic Load Balancing uses health checks to determine the availability and health of your instances. If an instance fails the health check, it is marked as unhealthy, and the load balancer will stop sending traffic to that instance until it becomes healthy again.

How much does Elastic Load Balancing cost?

The cost of Elastic Load Balancing depends on the type of load balancer you are using, the number of hours your load balancer is running, the amount of data processed, and the number of AWS resources in use. You can find detailed pricing information on the AWS Elastic Load Balancing pricing page.

Related Technology Terms

  • Load Balancer
  • Target Groups
  • Health Checks
  • Auto Scaling Groups
  • Listener Rules

Sources for More Information


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