What happens when multiple requests are received simultaneously by an AWS Lambda function?

  • AWS Lambda creates separate instances of the function to handle each request concurrently
  • AWS Lambda queues the requests and processes them sequentially
  • AWS Lambda randomly selects one request to process and discards the rest
  • AWS Lambda rejects the additional requests until previous ones are processed
When multiple requests are received simultaneously, AWS Lambda creates separate instances of the function, allowing each request to be processed concurrently without impacting others.

What are some factors affecting the scalability of AWS Lambda functions?

  • Concurrent executions
  • Function duration
  • Memory allocation
  • Network bandwidth
The number of concurrent executions allowed for a function can affect its scalability, as high concurrency can lead to resource contention and increased latency.

What is the default concurrency limit for AWS Lambda functions?

  • 1000
  • 2000
  • 250
  • 500
The default concurrency limit for AWS Lambda functions is 1000, which represents the maximum number of concurrent executions allowed for all functions within an AWS account.

Scenario: You're experiencing performance issues with your AWS Lambda functions due to high concurrency. What steps would you take to diagnose and address the problem?

  • Adjust Lambda Memory Allocation
  • Analyze CloudWatch Metrics
  • Optimize Code Efficiency
  • Scale Lambda Concurrency
Analyzing CloudWatch metrics can provide insights into performance issues caused by high concurrency in AWS Lambda functions.

Scenario: Your application requires bursty traffic handling, with occasional spikes in concurrent executions. How would you configure AWS Lambda to handle this effectively?

  • Adjust Memory Allocation
  • Configure Provisioned Concurrency
  • Enable Auto Scaling
  • Implement Queue-based Processing
Configuring provisioned concurrency in AWS Lambda ensures that a specified number of instances are always available to handle bursts of traffic, reducing cold start delays.

Scenario: Your team is designing a serverless architecture for a real-time chat application with thousands of concurrent users. What considerations would you make regarding AWS Lambda concurrency and scaling?

  • Implement Event Source Mapping
  • Monitor and Auto-scale
  • Set Appropriate Concurrency Limits
  • Use Multi-Region Deployment
Monitoring Lambda functions and enabling auto-scaling based on metrics such as invocation count or latency can dynamically adjust resources to match demand and ensure optimal performance for a real-time chat application with thousands of concurrent users.

What is the maximum size limit for a Lambda Layer?

  • 1 GB
  • 10 GB
  • 250 MB
  • 50 MB
The maximum size limit for a Lambda Layer is 50 MB, allowing you to include libraries, custom runtimes, and other dependencies.

How does AWS Lambda manage concurrency?

  • Automatically scales
  • Manually configured
  • Relies on external services
  • Uses a fixed pool
AWS Lambda automatically manages concurrency by scaling the number of function instances in response to incoming requests, ensuring that multiple requests can be processed concurrently.

What strategies can be employed to optimize concurrency and scaling in AWS Lambda?

  • Horizontal scaling
  • Manual scaling
  • Provisioning concurrency
  • Vertical scaling
Provisioning concurrency allows you to allocate a set number of execution environments, ensuring consistent performance and reducing cold start times in AWS Lambda.

What are some limitations to consider when designing highly concurrent AWS Lambda applications?

  • Account-level concurrency limits
  • Cold start latency
  • Event source limits
  • Resource contention
AWS Lambda imposes account-level concurrency limits, which can restrict the maximum number of concurrent executions across all functions in the account, requiring careful planning and monitoring.