Reactive Streams · interview question
Why is calling a blocking JDBC repository directly from a WebFlux event-loop thread dangerous?
Multiple choiceHardchapter-19-curatedpremiumreactive-streamsblocking-the-event-loop
Answer and explanation
Correct answer
D. It stalls one of the few event-loop threads that the server depends on for responsiveness.
Why
WebFlux relies on a small number of event-loop threads. If one of those threads blocks on JDBC or another blocking API, it cannot keep servicing other connections, so overall responsiveness can collapse quickly under load.
Test yourself on Reactive Streams
A free test with instant, explained results. No account needed.
More Reactive Streams questions
- Why is it essential to avoid legacy JDBC in a reactive WebFlux application?
- What would be the effect of calling request(Long.MAX_VALUE) on a Subscription?
- Why does a Subscriber in the Reactive Streams specification matter in this design?
- How would you explain a key difference between WebFlux and virtual threads for handling concurrency in an interview?
- Which method in a Subscriber handles the completion signal from a Publisher?
- How do Virtual Threads in Project Loom aim to simplify concurrent programming compared to WebFlux?