AWS Lambda vs. EC2: When to choose serverless features?

In a world of rapidly evolving cloud computing technologies, choosing the right solution can significantly impact the performance, cost and scalability of an application. AWS offers a wide range of services, the most popular of which are Amazon EC2 (Elastic Compute Cloud) and AWS Lambda. Both solutions have their unique advantages, and the decision between the two depends on the specifics of your project. In this article, we'll take a look at the differences between EC2 and Lambda and suggest when it makes sense to bet on serverless solutions.

What is AWS Lambda?

AWS Lambda is a serverless computing service that allows you to run code in response to events without managing servers. All you need to do is upload your code, set your triggers and Lambda automatically takes care of the rest, including scaling, monitoring and maintaining your infrastructure.

Key features of AWS Lambda:

• No server management: No need to worry about configuration, upgrades or scaling infrastructure.
• Automatic scaling: Lambda scales to the number of calls, whether you are running one function or millions.
• Payment model: You only pay for the time the function actually executes (in millisecond increments), making Lambda cost-effective for occasional workloads.

What is Amazon EC2?

Amazon EC2 is a service that allows you to rent virtual servers in the cloud. EC2 gives you full control over the operating system, applications and configuration, allowing you to tailor the environment to your specific needs.

Key features of EC2:

• Full control: You have access to the operating system, allowing you to install any software and manage your environment.
• Flexible scaling options: EC2 allows for manual or automatic scaling of computing power.
• Variety of instances: AWS offers a wide range of EC2 instances to suit different workloads (e.g. optimised for CPU, memory or GPU).

When to choose AWS Lambda?

AWS Lambda is the ideal solution when:

1. You perform short-lived tasks: Lambda is optimised for functions that run in response to specific events, such as processing data from S3, responding to API requests or analysing logs.
2. You have unpredictable workloads: Thanks to automatic scaling, Lambda works well in environments with fluctuating traffic.
3. You want to minimise costs: A payment model based on function execution time can be more cost-effective than renting a fixed instance.
4. You don't want to manage servers: If you want to focus solely on business logic without worrying about infrastructure, Lambda would be an excellent choice.

Examples of Lambda applications:

• Sending notifications in response to application events.
• Transforming data before storing it in the database.
• Running cron jobs (e.g. daily reports).

When to choose Amazon EC2?

Amazon EC2 will work well when:

1. You need full control over your environment: If you need to configure your own operating system or install custom software, EC2 is essential.
2. You are running long-term workloads: Fixed applications running 24/7 (e.g. web servers, databases) are more efficient on EC2.
3. You have complex requirements: For large applications with non-standard network configurations, EC2 gives you the freedom to customise your environment.
4. You want to optimise costs for stable workloads: For stable loads, EC2 can be more cost-effective by reserving instances or using spot instances.

Examples of EC2 applications:

• Hosting large-scale web applications.
• Deploying custom data analytics systems.
• Applications requiring large amounts of RAM or processing power (e.g. AI, ML).

Lambda and EC2 in practice: a hybrid approach

In many cases, a combination of both services may be the best solution. For example:

• Lambda as front-end: Handles API requests and processes data.
• EC2 as a back-end: Manages the database or handles complex calculations.

A hybrid approach maximises the advantages of both solutions, tailoring the infrastructure to the specific requirements of the project.

Summary

AWS Lambda and Amazon EC2 are two different approaches to cloud computing, each ideal for different scenarios. Lambda stands out for its simplicity and flexibility, while EC2 offers full control and extensive configuration options. The choice between the two should depend on the characteristics of your project, technical requirements and anticipated load.

If you are faced with a choice, ask yourself: do I care more about flexibility and control or simplicity and cost efficiency? The answer to this question will help you make the best decision for your application.