The most important Lambda concept is the Lambda function. Lambda is accessible from AWS Management Console and AWS Command Line Interface (CLI). After uploading, you associate your function with specific AWS resources. When a resource changes, Lambda will execute any functions that are associated with it. It will launch and manage compute resources as needed in order to keep up with incoming requests.
Creation of Lambda function is shown on the following screenshot:
Each function can be edited and tested from the Console after creation:
Results of function execution are shown on the following screenshot:
Lambda collects a set of metrics for each function and sends them to Amazon CloudWatch. All metrics can be viewed from the Console.
As for the pricing policy, the cost of using Lambda depends on the number of requests and the duration of compute time. First 1 million requests each month are free, but every million thereafter will cost $0.20. Compute time is charged for every 100 milliseconds. However, a free tier is also available for up to 1 million requests and 3.2 million seconds of compute time each month.
