Redis Caching in Java: TTL, Invalidation, and Consistency Tests
Debug Redis cache consistency in a Java service with cache-aside reads, TTL, invalidation, stale data, and database failures. Includes repeatable failure tests.
MySQL and ClickHouse Consistency: Outbox and Recovery
Keep MySQL and ClickHouse aligned with an outbox, versioned writes, reconciliation queries, and explicit recovery for delayed or duplicate events.
MySQL to ClickHouse: Scaling a Student Fitness Platform
A student fitness platform evolves from MySQL writes to ClickHouse analytics with bounded imports, outbox delivery, and query-oriented views.
MySQL LEFT JOIN with OR: Match Semantics Before Plans
Distinguish OR matching from priority fallback, control row multiplication, and validate MySQL join rewrites with execution plans and semantic tests.
Java Heap OOM with Arthas: Find Retained Data Before Raising -Xmx
A reproducible Arthas workflow for Java heap OOMs: identify retained objects, connect them to an import path, and verify chunked processing with memory checks.
Java Performance: Remove Repeated Searches and Unnecessary Work
Reduce repeated searches, unnecessary sorting, eager fallback calls, and excess memory retention, then verify changes with correctness tests, JFR, and JMH.
Java Transactions: Orders, Stock, and Outbox Events
A practical Spring and MySQL order workflow: define transaction boundaries, reserve stock safely, deduplicate retries, and deliver committed events through an outbox.