Serverless vs container decision in AWS - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Choosing between serverless and containers for a bursty workload

You have a web application with unpredictable traffic spikes that last only a few minutes. Which deployment option is best to handle this efficiently?

A Use serverless functions that automatically scale with demand and charge per execution.

B Use containers on EC2 instances with fixed capacity to handle peak load.

C Use containers on a single large EC2 instance to simplify management.

D Use serverless functions but limit concurrency to avoid scaling.

💡 Hint

Think about cost and automatic scaling for short bursts.

Serverless functions scale automatically and you pay only for actual usage, making them ideal for unpredictable, short bursts. Containers on fixed EC2 instances may waste resources or fail to scale quickly.

❓ Architecture

intermediate

Designing a microservices app with mixed compute needs

You are designing a microservices app where some services need long-running processes and others are event-driven and short-lived. Which architecture fits best?

A Use containers for long-running services and serverless for short-lived event-driven ones.

B Deploy all services as containers to unify deployment.

C Deploy all services as serverless functions for simplicity.

D Use serverless for long-running services and containers for short-lived ones.

💡 Hint

Consider which compute model suits long-running versus short-lived tasks.

Containers are better for long-running processes because serverless functions have execution time limits. Serverless is ideal for short-lived, event-driven tasks due to automatic scaling and cost efficiency.

❓ security

advanced

Security considerations for serverless vs containers

Which security concern is more critical when using containers compared to serverless functions?

A Handling automatic scaling to prevent denial of service.

B Ensuring function execution time limits are not exceeded.

C Managing the underlying OS patching and vulnerabilities.

D Configuring event triggers securely.

💡 Hint

Think about who manages the OS in each model.

Containers require you to manage the OS and patch vulnerabilities, while serverless abstracts this away. Execution time limits and event triggers are more relevant to serverless.

❓ service_behavior

advanced

Cold start impact on serverless functions

What is the main impact of cold starts in serverless functions on user experience?

A Failure to execute the function on first request.

B Longer initial response time when a function is invoked after inactivity.

C Permanent downtime until function is redeployed.

D Increased cost due to longer execution time.

💡 Hint

Consider what happens when a function is called after not being used for a while.

Cold starts cause a delay in the first invocation after inactivity, leading to longer response times. They do not cause failures or permanent downtime.

✅ Best Practice

expert

Optimizing cost and performance in hybrid serverless-container apps

You run a hybrid app with containers for core services and serverless for auxiliary tasks. Which practice best optimizes cost and performance?

A Keep containers running at full capacity 24/7 and use serverless only for peak loads.

B Use serverless for all tasks to avoid managing containers.

C Convert all container services to serverless to unify billing.

D Scale containers dynamically based on load and use serverless for unpredictable, short tasks.

💡 Hint

Think about scaling and cost efficiency for different workload types.

Dynamic scaling of containers saves cost and matches performance needs. Serverless suits unpredictable short tasks. Running containers at full capacity wastes resources. Converting all to serverless may not fit long-running needs.