14. Scalability and load balancing with EC2

One of the key benefits of using Amazon Web Services (AWS) is the ability to quickly and efficiently scale resources to meet the demands of an application. This is particularly true when it comes to EC2 servers, which can be easily scaled up or down depending on needs. In addition, AWS offers several load balancing tools that help distribute network traffic across multiple servers to ensure that no server is overloaded.

Scalability with EC2

Scalability is a key feature of cloud computing. It allows you to adjust computing resources to meet application demands, whether increasing capacity during peak demand or decreasing capacity during periods of low demand. This is known as vertical and horizontal scalability.

Vertical scaling involves increasing or decreasing the capacity of a single EC2 server. For example, you can start with a small EC2 server and, as demand increases, move to a larger server. This can easily be done on AWS, but requires the server to be shut down during the process.

Horizontal scaling, on the other hand, involves adding or removing EC2 servers. This can be done without service interruption and is generally preferred over vertical scaling as it allows for greater flexibility and is more cost-effective. AWS offers a tool called Auto Scaling to facilitate horizontal scaling.

Auto Scaling

AWS Auto Scaling allows you to set up scaling policies that automatically adjust the number of EC2 instances based on predefined conditions. For example, you can configure a policy to add more EC2 instances when CPU utilization reaches a certain threshold, and remove instances when CPU utilization drops below a certain threshold.

In addition, Auto Scaling allows you to keep a minimum number of EC2 instances running at all times, ensuring your application is always available. This is particularly useful for applications that need to be available 24/7, such as eCommerce websites.

Load Balancing with EC2

In addition to scalability, AWS also offers several tools for load balancing. Load balancing is a technique that distributes network traffic across multiple servers to ensure that no server is overloaded. This can help improve application performance and availability.

The Elastic Load Balancer (ELB) is the main load balancing tool for AWS. It supports three types of load balancers: classic load balancer, application load balancer, and network load balancer.

The classic load balancer is the original version of the ELB and is used to balance HTTP/HTTPS and TCP traffic. The application load balancer is a more advanced version that supports content-based load balancing, allowing you to direct traffic to different services based on the content of the requests. Network Load Balancer is used to balance TCP, UDP and TLS traffic where extreme performance is required.

In summary, scalability and load balancing are two critical features that AWS provides to help manage EC2 servers. With these tools, you can ensure that your application is always available and can handle any amount of traffic.

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