distributed systems
9 minDistributed Systems Foundations: Consistency, Retries, and Delivery Semantics
Separate consistency guarantees from delivery guarantees and design for the partial failures that make retries necessary.
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distributed systems
9 minIdempotency and the Transactional Outbox: Making Retries Safe
Learn why network retries create duplicate effects and how idempotency keys and an outbox close common reliability gaps.
databases
10 minDatabase Locks and Isolation: Diagnose Blocking, Deadlocks, and Retries
Understand transaction conflicts, lock waits, isolation anomalies, and safe retry boundaries across relational databases.
databases
8 minPostgreSQL concurrent indexes: reason about locks, retries, and invalid states
Use concurrent index builds without assuming they are lock-free or all-or-nothing.
devops
6 minScheduled jobs: separate a logical run from its attempts
Give retries a stable business identity without confusing schedule windows with process start times.
Q&A
Q&AWhat does idempotence guarantee for an HTTP operation?
Idempotence describes the intended effect, not identical response bytes or status codes. POST needs an explicit deduplication contract before ambiguous retries are safe.
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Idempotence describes the intended effect, not identical response bytes or status codes. POST needs an explicit deduplication contract before ambiguous retries are safe.
Q&A
Q&AWhat does asyncio queue completion actually prove?
Every accepted item has been acknowledged, not necessarily committed successfully.
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A bounded queue limits waiting items; workers hold additional active items. task_done releases unfinished-item accounting, while business success and durable retries require separate records.
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.