With Cloud Computing replacing layer after layer of server room hardware with virtual servers, what if you could virtualize the servers themselves out of existence? In a way, this is AWS Lambda.
It’s not uncommon to require your cloud-based apps to wake up and deliver some functionality when triggered by external events, but designing the process can be complicated. For example, I might need my application to respond every time there’s a change to the objects in one of my S3 buckets. Normally, I would configure some kind of service bus (in AWS, that would be SQS) to listen for S3 change notification, so that my app code, which is listening to SQS, can respond. All that can certainly work well. But managing the code and compute resources carries a significant operating overhead.
To address such challenges, Amazon created AWS Lambda, a service that can run your code in response to events and automatically manage the compute resources for you.
Events that can trigger a Lambda function
You can configure these events to trigger Lambda functions:
- Table updates in Amazon DynamoDB.
- Modifications to objects in S3 buckets.
- Notifications sent from Amazon SNS.
- Messages arriving in an Amazon Kinesis stream.
- AWS API call logs created by AWS CloudTrail.
- Client data synchronization events in Amazon Cognito.
- Custom events from mobile applications, web applications, or other web services.
How is AWS Lambda different from Amazon’s Elastic Beanstalk or EC2 Container Service?
When I first read about AWS Lambda I was confused. I wasn’t sure whether it was another PaaS (Platform as a Service) or a Docker-like container service like AWS ECS. In both those cases, developers push their code, and the rest (including compute deployment and application container provisioning) is taken care of by the service. So what’s all the fuss about Lambda?
But I eventually became aware of some key differences that help differentiate Lambda from all the others. Look more closely at Amazon’s EC2 Containers. Even though containers are highly scriptable, you are still responsible for maintaining them through their lifecycles. Since ECS only provides runtime execution services, everything else is in your hands. Lambda functions, on the other hand, are far more self-sufficient. Therefore, while Lambda has some features in common with EC2 Containers, it’s obviously much more than that.
Ok. If it’s not a container service, then perhaps it’s a platform like Elastic Beanstalk? Clearly not. Though Lambda does provide a kind of platform for developers, it’s much simpler than Beanstalk. Once your Lambda application is deployed, for instance, it can’t be accessed from the public network – unlike Beanstalk apps which can be accessed via their REST endpoints.
So in short, Lambda inherited some features from the EC2 Container Service and others from Elastic beanstalk, but it’s conceptually distant from both.
What does AWS Lambda do?
Now that we’ve got a bit more clarity about what AWS Lambda is, we can discuss ways to use it. Here are some common needs:
- Application developers writing event-driven applications want seamless integration between their AWS-based applications.
- Streaming data from AWS services like Kinesis and Dynamo DB needs processing.
- AWS Lambda can be configured with external event timers to perform scheduled tasks.
- Logs generated by AWS services like S3, Kinesis, and dynamoDB can be dynamically audited and tracked.
It might be helpful to take these Lambda features into account as you decide if this service is right for your project:
- AWS Lambda works only within the AWS ecosystem.
- AWS Lambda can be configured with external event timers, and can, therefore, be used for scheduling.
- Lambda functions are stateless, so they can quickly scale.
- More than one Lambda function can be added to a single source.
- AWS Lambda is fast: it will execute your code within milliseconds.
- AWS Lambda manages all of the compute resources required for your function and also provides built-in logging and monitoring through CloudWatch.
Watch this short video – taken from Understanding AWS Lambda to Run & Scale your code Course – to get a general understanding of how to run and scale your code with AWS Lambda.
Getting Started with AWS Lambda and DynamoDB
Now let’s get our hands dirty with a simple project using AWS Lambda and DynamoDB – AWS’s in-house NoSQL database. DynamoDB will be the source of our trigger and Lambda will respond to those changes. We will use node.js to write our function.
Here’s how it will work: if there is any change in a specified DynamoDB table, it should trigger a function that will print the event details. Let’s take it step-by-step:
1. Create a Lambda Service
- Login to the AWS console
- Click on Lambda
- You will be asked to select a blueprint. Blueprints are sample configurations of event sources and Lambda functions. You can ignore this by clicking on skip.
- Provide Lambda with some basic details as shown below and paste the Node.js code that you want to be triggered automatically whenever a new item is added in dynamoDB. Also, make sure the Role you select has all the required permissions.
Note: The selected role should have the following policy attached to it:
- Verify the details in the next screen and click Create Function.
- Now, if you select the Lambda service you’ve created and click the Event Sources tab, there will be no records. But there should be an entry pointing to the source to which the Lambda function will respond. In our case its dynamo DB.
2. Create a DynamoDB table
Follow these steps to create a new Dynamo DB table:
- Login to the AWS console.
- Select DynamoDB.
- Click Create Table and fill out the form that will appear as below:
- Click Continue and, again, enter appropriate details into the form. Then click “Add Index to Table” as shown.
- Once your index has been created, you can verify it under Table Indexes.
- Clicking Continue will generate this screen:
We don’t need to make any changes, just click Continue. In the next screen, un-check the “Use Basic Alarms ”check box (assuming you don’t need any notifications).
- Click Continue once again and you will see a verification screen. Verify that everything looks the way it should and click Create.
- Now select your new table. Go to the Streams tab and associate it with the Lambda function that you created in Step 1.
Once your Lambda function is associated, you will see its entry in Event Sources tab of the Lambda service page.
- Now go to your DynamoDB table and add a new item. In our example, we added an item with the ID “10” and the Name “My First Lambda service is up and running”. Once the item is added and saved, our Lambda service should trigger the function. This can be verified by viewing the Lambda logs. To do that, select the Lambda service and click on the Monitoring tab. Then click View Logs in CloudWatch.
- Select the Log Group and check the log.
The output will be something like this:
If you want to get a deepen your knowledge on serverless, check out Cloud Academy’s Getting Started with Serverless Computing on AWS Learning Path.
Have any thoughts or comments? Join the discussion below.
Top 5 AWS Salary Report Findings
At the speed the cloud tech space is developing, it can be hard to keep track of everything that’s happening within the AWS ecosystem. Advances in technology prompt smarter functionality and innovative new products, which in turn give rise to new job roles that have a ripple effect on t...
New on Cloud Academy: Red Hat, Agile, OWASP Labs, Amazon SageMaker Lab, Linux Command Line Lab, SQL, Git Labs, Scrum Master, Azure Architects Lab, and Much More
Happy New Year! We hope you're ready to kick your training in overdrive in 2020 because we have a ton of new content for you. Not only do we have a bunch of new courses, hands-on labs, and lab challenges on AWS, Azure, and Google Cloud, but we also have three new courses on Red Hat, th...
Cloud Academy’s Blog Digest: Azure Best Practices, 6 Reasons You Should Get AWS Certified, Google Cloud Certification Prep, and more
Happy Holidays from Cloud Academy We hope you have a wonderful holiday season filled with family, friends, and plenty of food. Here at Cloud Academy, we are thankful for our amazing customer like you. Since this time of year can be stressful, we’re sharing a few of our latest article...
Google Cloud Platform Certification: Preparation and Prerequisites
Google Cloud Platform (GCP) has evolved from being a niche player to a serious competitor to Amazon Web Services and Microsoft Azure. In 2019, research firm Gartner placed Google in the Leaders quadrant in its Magic Quadrant for Cloud Infrastructure as a Service for the second consecuti...
New Lab Challenges: Push Your Skills to the Next Level
Build hands-on experience using real accounts on AWS, Azure, Google Cloud Platform, and more Meaningful cloud skills require more than book knowledge. Hands-on experience is required to translate knowledge into real-world results. We see this time and time again in studies about how pe...
New on Cloud Academy: AWS Solution Architect Lab Challenge, Azure Hands-on Labs, Foundation Certificate in Cyber Security, and Much More
Now that Thanksgiving is over and the craziness of Black Friday has died down, it's now time for the busiest season of the year. Whether you're a last-minute shopper or you already have your shopping done, the holidays bring so much more excitement than any other time of year. Since our...
Understanding Enterprise Cloud Migration
What is enterprise cloud migration? Cloud migration is about moving your data, applications, and even infrastructure from your on-premises computers or infrastructure to a virtual pool of on-demand, shared resources that offer compute, storage, and network services at scale. Why d...
6 Reasons Why You Should Get an AWS Certification This Year
In the past decade, the rise of cloud computing has been undeniable. Businesses of all sizes are moving their infrastructure and applications to the cloud. This is partly because the cloud allows businesses and their employees to access important information from just about anywhere. ...
AWS Regions and Availability Zones: The Simplest Explanation You Will Ever Find Around
The basics of AWS Regions and Availability Zones We’re going to treat this article as a sort of AWS 101 — it’ll be a quick primer on AWS Regions and Availability Zones that will be useful for understanding the basics of how AWS infrastructure is organized. We’ll define each section,...
Application Load Balancer vs. Classic Load Balancer
What is an Elastic Load Balancer? This post covers basics of what an Elastic Load Balancer is, and two of its examples: Application Load Balancers and Classic Load Balancers. For additional information — including a comparison that explains Network Load Balancers — check out our post o...
Advantages and Disadvantages of Microservices Architecture
What are microservices? Let's start our discussion by setting a foundation of what microservices are. Microservices are a way of breaking large software projects into loosely coupled modules, which communicate with each other through simple Application Programming Interfaces (APIs). ...
Kubernetes Services: AWS vs. Azure vs. Google Cloud
Kubernetes is a popular open-source container orchestration platform that allows us to deploy and manage multi-container applications at scale. Businesses are rapidly adopting this revolutionary technology to modernize their applications. Cloud service providers — such as Amazon Web Ser...