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.
New Content: Azure DP-100 Certification, Alibaba Cloud Certified Associate Prep, 13 Security Labs, and Much More
This past month our Content Team served up a heaping spoonful of new and updated content. Not only did our experts release the brand new Azure DP-100 Certification Learning Path, but they also created 18 new hands-on labs — and so much more! New content on Cloud Academy At any time, y...
AWS Certification Practice Exam: What to Expect from Test Questions
If you’re building applications on the AWS cloud or looking to get started in cloud computing, certification is a way to build deep knowledge in key services unique to the AWS platform. AWS currently offers 12 certifications that cover major cloud roles including Solutions Architect, De...
Overcoming Unprecedented Business Challenges with AWS
From auto-scaling applications with high availability to video conferencing that’s used by everyone, every day — cloud technology has never been more popular or in-demand. But what does this mean for experienced cloud professionals and the challenges they face as they carve out a new p...
Constant Content: Cloud Academy’s Q3 2020 Roadmap
Hello — Andy Larkin here, VP of Content at Cloud Academy. I am pleased to release our roadmap for the next three months of 2020 — August through October. Let me walk you through the content we have planned for you and how this content can help you gain skills, get certified, and...
New Content: Alibaba, Azure AZ-303 and AZ-304, Site Reliability Engineering (SRE) Foundation, Python 3 Programming, 16 Hands-on Labs, and Much More
This month our Content Team did an amazing job at publishing and updating a ton of new content. Not only did our experts release the brand new AZ-303 and AZ-304 Certification Learning Paths, but they also created 16 new hands-on labs — and so much more! New content on Cloud Academy At...
Blog Digest: Which Certifications Should I Get?, The 12 Microsoft Azure Certifications, 6 Ways to Prevent a Data Breach, and More
This month, we were excited to announce that Cloud Academy was recognized in the G2 Summer 2020 reports! These reports highlight the top-rated solutions in the industry, as chosen by the source that matters most: customers. We're grateful to have been nominated as a High Performer in se...
Which Certifications Should I Get?
The old AWS slogan, “Cloud is the new normal” is indeed a reality today. Really, cloud has been the new normal for a while now and getting credentials has become an increasingly effective way to quickly showcase your abilities to recruiters and companies. With all that in mind, the s...
New Content: AWS, Azure, Typescript, Java, Docker, 13 New Labs, and Much More
This month, our Content Team released a whopping 13 new labs in real cloud environments! If you haven't tried out our labs, you might not understand why we think that number is so impressive. Our labs are not “simulated” experiences — they are real cloud environments using accounts on A...
Kickstart Your Tech Training With a Free Week on Cloud Academy
Are you looking to make a jump in your technical career? Want to get trained or certified on AWS, Azure, Google Cloud Platform, DevOps, Kubernetes, Python, or another in-demand skill? Then you'll want to mark your calendar. Starting Monday, June 22 at 12:00 a.m. PDT (3:00 a.m. EDT), ...
New Content: AZ-500 and AZ-400 Updates, 3 Google Professional Exam Preps, Practical ML Learning Path, C# Programming, and More
This month, our Content Team released tons of new content and labs in real cloud environments. Not only that, but we introduced our very first highly interactive "Office Hours" webinar. This webinar, Acing the AWS Solutions Architect Associate Certification, started with a quick overvie...
Azure vs. AWS: Which Certification Provides the Brighter Future?
More and more companies are using cloud services, prompting more and more people to switch their current IT position to something cloud-related. The problem is most people only have that much time after work to learn new technologies, and there are plenty of cloud services that you can ...
Blog Digest: 5 Reasons to Get AWS Certified, OWASP Top 10, Getting Started with VPCs, Top 10 Soft Skills, and More
Thank you for being a valued member of our community! We recently sent out a short survey to understand what type of content you would like us to add to Cloud Academy, and we want to thank everyone who gave us their input. If you would like to complete the survey, it's not too late. It ...