What Is AWS Lambda? AWS Lambda Tutorial for AWS Solution Architects

AWS Lambda is an Amazon web service; it also offers many other services like AWS EC2, AWS Ops works, and AWS Elastic Beanstalk etc. In this tutorial, we will discuss what is AWS Lambda? What are the uses, its limitations, pricing scheme, events etc. Let us dive deep into the each of the topics throughout the article one by one.

What is Amazon Lambda?

Amazon’s Lambda lets the user run the code in a serverless environment as stated by Amazon on its Lambda product page. Basically, Lambda can be thought of as an event-driven computing platform. It runs when an event triggers it by code execution that has been loaded into the system.

Here, the image uploading case can be taken as an example, in which the image resizing can be performed easily by Lambda function automatically. Some companies use this function for auto-resizing the images for various devices including mobile, tablet and desktop devices, here the file that is uploaded to S3 is used by the event that invokes Lambda function, after which the image resizing function gets executed.

Here, the customers only have to pay for using the function, when it gets executed, so the organizations only pay to Amazon when the image resizing takes place.

Lambda function can also be helpful at the time of online shopping. Here when an online order is placed an Amazon DynameDB NoSQL entry is made, that can trigger the Lambda function that can load order detail to Amazon Redshift that is a data warehouse of Amazon.

When the event-driven applications are written by AWS professional then they want to do seamless integration between AWS applications and the services of Kinesis and Dynamo DB may need processing. AWS Lambda can be configured with external events and along with a schedule. The logs created by the function can be dynamically audited and tracked.

Lambda function of AWS only works within the AWS ecosystem and can be configured with external event timers, so can be used for scheduling. They are scalable as they are stateless. To a single source, you can add more than one Lambda function.

How to implement Server less Architecture with AWS Lambda?

Some organizations may think that it can be difficult to opt serverless, but with the help of the right tools and practices, the applications can become fully functional even only with a few lines of code. Some of the server-less applications that can use a Lambda function are listed below:

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• Virtual Assistants and Chatbots: Now you can interact in a server-less manner with your customers. Your chatbots and customer support assistants can remain engaged, including your social media pages. Here the most used kits are Amazon Alexa Skill Kit or Amazon Lex that can use natural language to understand voice and have freedom of using text input. You can intelligently interact with your customers through these functions.
• Mobile and Web Backends: In an S3 bucket, static web content or native mobile application content can be created in completely server-fewer manners for mobile applications and websites. Front-end content can also be integrated with Amazon API Gateway and it will work as a backend service, Lambda functions are responsible to execute business logic that is written for API Gateways.
• Internet of Things Backends: AWS IoT can be directly integrated for the device messages that can be routed to process Lambda functions. It means that server-less backend functions can be implemented easily that are supposed to be highly secure, scalable IoT applications.

Unlike traditional server-based environments, AWS Lambda is a server-less platform that can provide faster development and greater experimentation in an innovative manner.

Amazon Lambda is a server-less compute service, that means that the developers need not be worried about AWS resources and here resource management is linked with terminating, launching, auto-scaling, health checkups, patching and updating.

Where and How AWS Lambda is used?

Your backend code is executed by AWS Lambda and can manage the AWS resources. As far as resource management is concerned then it includes auto-scaling, health checkups, patching of new updates and launching and terminating new instances.

If you want to know that how Lambda code works then it is done by Lambda function and it only runs when it is being called by any event. Here, event source entity triggers a Lambda function and then the task gets executed.

Let's understand AWS working with an example, suppose you have to architect a problem solution and you want to know that where you should use a Lambda function, then it can be achieved in many steps.

Use of AWS Lambda for Function Uploading

When an image is uploaded then a number of tasks are performed to accomplish it. These tasks are image resizing, filter application and compression. So the complete task of image uploading can be said an Event Source or trigger that can call a Lambda function, all of these tasks is executed by Lambda function.

Let's understand this example in terms of AWS, where the image will be uploaded in the S3 bucket form that will be like a trigger or event source. The complete process is divided into below-listed five steps:

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• The image is uploaded in the source bucket S3 that also has attached notifications for Lambda.
• S3 reads the notifications and decides where they should be sent.
• The notifications are sent to S3 by Lambda that acts as a function invoking call
• IAM or Identity and Access Management can give access permission for AWS resources.
• Finally desired Lambda function that works on the object is uploaded to S3 bucket

Earlier the complete task was usually managed by the developers in the following steps:

• Scaling up, sizing and provisioning servers
• OS update management
• Security patches application
• Monitoring infrastructure for availability and performance management

It can be a tedious, expensive and tiresome task that can justify the need of Lambda function. AWS Lambda is compatible with Python, Java, Node.JS so that a file can be uploaded in zip format that can define event source and other related information.

Now let’s see how Lambda works here?

• Where should this Lambda function be used?
• What purpose is served by Lambda that other computing services cannot do?

For architect designing, you will have to perform the following steps for the accomplishment of any task:

• AWS EC2
• AWS Elastic Beanstalk
• AWS Ops Works
• AWS Lambda

AWS Lambda Limitations

Some of the Lambda function limitations are hardware specific while other may be architecture related. Let's see all of them:

Hardware limitation can be understood as the disk size needed for AWS Lambda can range from 128MB to 1536MB and the request execution time can be just 5 minutes and request payload time cannot be more than 6MB. Actually, these limitations are the boundaries that should be set while designing architecture of AWS Lambda function. You can use other AWS disposal services that can be used.

Lambda Function Pricing

Like other AWS services, AWS Lambda is also a pay per use service, that means you will have to pay only for those services that are used by you. So as far as charges are concerned then you will be charged only for the following parameters:

• Total number of requests that are made for Lambda function
• Total duration for which the code gets executed

Both of these terms can be understood in the following paragraph:

If we talk about Requests then it means the total number of requests that are made for all of the lambda functions throughout the project. AWS Lambda function counts the requests when the function starts getting executed that can be a response of an invoke call or event source, it also includes the test that is invoked from the console.

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The call prices are calculated as the first 1 million requests every month are free and thereafter 0.20$ is charged per million requests.

For the duration, it is calculated from the moment when your code starts executing till the moment it gets terminated. The total time is rounded up to the nearest 100ms. The price or total memory cost that you allocate to your function, you may be charged $0.00001667 per GB-second that is used by you.

Events that can trigger an AWS Lambda function

Following events can be configured to call Lambda function:

• Object modification in S3 buckets
• To sent notifications from Amazon SNS
• The arrival of messages in an Amazon Kinesis stream
• Table updating in Amazon DynamoDB

AWS Lambda works on ‘push’ or ‘pull’ event models and the function can be written in either JavaScript or Node.js and Java language.

Final Words:

Today, AWS Lambda has become one of the most used Lambda functions and provides you with a plenty of benefits. The article discussed the Lambda function in detail and it has become one of the favorite functions of DevOps professionals today. You should use these functions as and when required and they can enhance the usability of the application when invoked correctly.

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