Scenario: You're developing a serverless application that requires frequent access to a third-party API. How would you implement resource reuse to optimize performance and reduce costs?
- Allocate more memory to Lambda functions
- Increase the function timeout for API calls
- Use VPC endpoints for API access
- Utilize AWS Lambda Layers to cache API clients
Utilizing AWS Lambda Layers to cache API clients helps in reusing the initialized clients across function invocations, optimizing performance and reducing costs by minimizing repeated initializations.
Scenario: Your team is experiencing high latency in AWS Lambda functions due to repeated initialization of resources. How would you redesign the architecture to leverage resource reuse effectively?
- Create new resources for each invocation
- Increase the function's memory allocation
- Initialize resources outside the handler function
- Use Amazon S3 for resource storage
Initializing resources outside the handler function allows them to be reused across multiple invocations, effectively reducing high latency caused by repeated initializations.
Scenario: You're tasked with optimizing the cost of a serverless application running on AWS Lambda. How would you identify opportunities for resource reuse and implement them efficiently?
- Analyze and optimize the initialization code to be outside the function handler
- Implement CloudWatch Logs for monitoring
- Increase the memory and timeout settings
- Use reserved concurrency
Analyzing and optimizing the initialization code to be outside the function handler helps in reducing repeated initializations, thus optimizing costs by reusing resources efficiently.
What is the purpose of load testing in performance testing?
- To check for software bugs
- To enhance security measures
- To evaluate how the system performs under heavy load
- To improve code quality
Load testing evaluates how the system performs under heavy load, identifying maximum capacity and performance bottlenecks.
What is the difference between stress testing and load testing?
- Load testing evaluates system recovery after failure
- Load testing measures system performance under expected load
- Stress testing and load testing are the same
- Stress testing evaluates system behavior under extreme conditions
Stress testing evaluates system behavior under extreme conditions, while load testing measures system performance under expected load.
How can you measure response time in performance testing?
- Observing user feedback
- Reviewing system logs
- Using a stopwatch to manually time responses
- Utilizing performance testing tools like JMeter
Utilizing performance testing tools like JMeter is the most effective and accurate method to measure response time in performance testing.
Which metric is commonly used to assess the scalability of a system in performance testing?
- Error rate
- Latency
- Response time
- Throughput
Throughput is commonly used to assess the scalability of a system, indicating how well the system can handle increased loads.
What are some common challenges faced during performance testing of distributed systems?
- Hardware limitations
- Limited test data
- Network latency
- Software bugs
Network latency, due to the distributed nature of the system, can significantly impact performance testing results, making it a common challenge.
In performance testing, __________ is the process of determining how a system behaves under different conditions.
- Load testing
- Regression testing
- Stress testing
- Unit testing
Load testing is the process of determining how a system behaves under different conditions by simulating multiple users or transactions.
__________ is the process of gradually increasing the load on a system until it reaches its breaking point.
- Load balancing
- Reliability testing
- Scalability testing
- Stress testing
Stress testing is the process of gradually increasing the load on a system until it reaches its breaking point, helping identify the system's limits.