Follow-up · depth 5
How would you debug production issues related to CompletableFuture Composition?
How would you debug production issues related to CompletableFuture Composition?
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Audio N/AQuick interview answer
Debug CompletableFuture Composition by confirming blast radius, checking lag/error metrics, grabbing profiles/traces, then mitigating before deep root-cause. Logic: supplyAsync runs async task; thenApply transforms; thenCompose flattens nested futures; allOf waits for batch. Exceptionally/handle for error paths.
Detailed answer
Production debug playbook for CompletableFuture Composition: 1) Stabilize: rate-limit, shed load, or roll back if users are hurting. 2) Orient: dashboards for latency, errors, saturation tied to CompletableFuture Composition. 3) Evidence: traces, profiles, logs with correlation IDs. 4) Hypothesize + prove with a safe experiment. 5) Fix + add a regression test/alert so it cannot silently return. Watch for: Blocking get() on async chain in request thread; lost exceptions without handle. Parent context: Logic: supplyAsync runs async task; thenApply transforms; thenCompose flattens nested futures; allOf waits for batch. Exceptionally/handle for error paths.
Full explanation
Interviewers score structured incident thinking: mitigate → measure → root cause → prevent. supplyAsync runs async task; thenApply transforms; thenCompose flattens nested futures; allOf waits for batch. Exceptionally/handle for error paths.
Follow-up questions
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Parent context — CompletableFuture Composition
Logic: supplyAsync runs async task; thenApply transforms; thenCompose flattens nested futures; allOf waits for batch. Exceptionally/handle for error paths.
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