http
6 minHTTP conditional writes: detect an edit based on stale state
Use strong validators and atomic preconditions to prevent lost updates without confusing them with retry identity.
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10 matching resultsArticles and interview answers
Q&A
Q&ADoes If-Match make a lost-response write safely identifiable on retry?
No; it identifies an expected version, not a logical operation.
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A committed first attempt advances the validator, so a repeat with the old validator may fail with 412. Use a separate scoped idempotency contract when retries must recover the original result.
http
5 minReliable API Clients: Pagination, Conditional Requests, and Retry Budgets
Keep list traversal stable, validate cached representations, and bound retry work when networks fail at ambiguous points.
Q&A
Q&AWhat does a successful kubectl apply prove?
API acceptance is not convergence. Inspect rollout status, Pod conditions, and events to determine whether the desired workload is actually ready.
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API acceptance is not convergence. Inspect rollout status, Pod conditions, and events to determine whether the desired workload is actually ready.
http
5 minHTTP Foundations: Methods, Status Codes, and Representation Boundaries
Design a predictable request and response contract by distinguishing resources, representations, safe methods, and retryable operations.
Q&A
Q&AWhat happens when two Java HashMap keys have the same hash code?
The keys share a bucket, then equality distinguishes entries within that bucket.
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A hash helps select a bucket but does not establish key identity. HashMap checks equality among entries in the bucket; collisions can be stored in a list and, in sufficiently large bins, treeified under implementation conditions. Correct equals/hashCode behavior is essential, and resizing changes bucket placement without making hashes unique.
Q&A
Q&AWhat is the difference between WHERE and HAVING?
WHERE filters input rows before grouping; HAVING filters groups after aggregation.
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Use WHERE to remove rows before GROUP BY, such as excluding inactive employees. Use HAVING to filter aggregate results, such as departments with COUNT(*) greater than five. Moving a condition between them can change both meaning and query work.
Q&A
Q&AWhat happens when a Java thread calls wait()?
It must own the monitor, releases that monitor, and waits until notified or interrupted.
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Object.wait() requires ownership of that object’s monitor. The thread releases that monitor and enters a waiting state until notification, interruption, timeout, or spurious wakeup; it must reacquire the monitor before returning. Always wait in a while loop that rechecks the condition, and use higher-level concurrency utilities where possible.