85.How do I coordinate calls between multiple AWS Lambda functions?
You can use AWS Step Functions to coordinate a series of AWS Lambda functions in a specific order. You can invoke multiple Lambda functions sequentially, passing the output of one to the other, and/or in parallel, and Step Functions will maintain state during executions for you.
86. How do I troubleshoot a serverless application?
You can enable your Lambda function for tracing with AWS X-Ray by adding X-Ray permissions to your Lambda function’s execution role and changing your function’s ‘tracing mode’ to ‘active. ‘ When X-Ray is enabled for your Lambda function, AWS Lambda will emit tracing information to X-Ray regarding the Lambda service overhead incurred when invoking your function. This will provide you with insights such as Lambda service overhead, function init time, and function execution time. In addition, you can include the X-Ray SDK in your Lambda deployment package to create your own trace segments, annotate your traces, or view trace segments for downstream calls made from your Lambda function. X-Ray SDKs are currently available for Node.js and Java.
87. What are triggers in AWS Lambda ?
Triggers are services and resources that you have configured to invoke your function. Choose Add trigger to create a Lambda event source mapping or to configure a trigger in another service that the Lambda console integrates with.
88. How does AWS Lambda isolate the code?
Each AWS Lambda function runs in its own isolated environment, with its own resources and file system view. AWS Lambda uses the same techniques as Amazon EC2 to provide security and separation at the infrastructure and execution levels.
89. How does AWS Lambda secure the code?
AWS Lambda stores code in Amazon S3 and encrypts it at rest. AWS Lambda performs additional integrity checks while your code is in use.
90. How do I scale an AWS Lambda function?
You do not have to scale your Lambda functions – AWS Lambda scales them automatically on your behalf. Every time an event notification is received for your function, AWS Lambda quickly locates free capacity within its compute fleet and runs your code. Since your code is stateless, AWS Lambda can start as many copies of your function as needed without lengthy deployment and configuration delays.
91. How are compute resources assigned to an AWS Lambda function?
In the AWS Lambda resource model, you choose the amount of memory you want for your function, and are allocated proportional CPU power and other resources. For example, choosing 256MB of memory allocates approximately twice as much CPU power to your Lambda function as requesting 128MB of memory and half as much CPU power as choosing 512MB of memory.You can set your memory from 128MB to 10,240MB.
