For high-traffic applications, Spring MVC offers several advanced techniques beyond basic request handling that help the application scale, stay responsive, and use resources efficiently under load.
Key Points: • Asynchronous request processing, using DeferredResult or Callable return types, frees up servlet threads while a long-running operation completes elsewhere. • Caching frequently-read data reduces repeated database load, especially for read-heavy endpoints. • Connection pooling for databases and downstream HTTP clients avoids the overhead of creating new connections per request. • Content negotiation lets a single endpoint serve JSON, XML, or other formats depending on the client's Accept header, avoiding duplicate endpoints. • Rate limiting and circuit breakers, often via libraries like Resilience4j, protect the app from cascading failures when downstream services degrade. • Spring Security provides robust authentication and authorization that scales with the app rather than being bolted on ad hoc.
Example: A high-traffic reporting endpoint might use a Callable to offload a slow query onto a separate thread pool, freeing the request-handling thread, while a caching layer serves repeated identical report requests without hitting the database again.
Interview Tip: A concise interview answer is:
"For high-traffic systems I lean on asynchronous processing so slow operations don't tie up request threads, caching to cut down redundant database hits, and connection pooling for efficient resource use. I'd also add content negotiation for flexible clients and resilience patterns like circuit breakers to keep the app stable under load."