Performance

A comprehensive guide exploring why enabling HeapDumpOnOutOfMemoryError can cause significant performance issues in production environments, which OutOfMemoryError types actually trigger heap dumps, and better alternatives like JFR for memory leak detection and automatic service restart strategies.

A comprehensive comparison of PostgreSQL and MySQL for OLTP scenarios, exploring their fundamental architectural differences in secondary index handling and MVCC implementation, with practical insights on when to choose each database.

Discover when GraalVM Native Image processes show up in jps and learn our battle-tested approach for choosing between GraalVM Native Image and JVM in production environments. We break down our strategy for Lambda-style tasks versus long-running microservices.

Learn how to develop and test high-performance API clients using WebClient, TestContainers, and toxicproxy. This comprehensive guide covers asynchronous request handling, isolated testing environments, and realistic failure simulation for robust microservice development.

A deep dive into diagnosing and resolving a production JVM issue where applications would freeze during hourly log synchronization tasks. We explore safepoint analysis, JVM log output blocking, asynchronous logging implementation, and WebFlux optimization to achieve a complete solution.

A comprehensive exploration of pseudo-random number generators in Java, covering everything from basic Linear Congruential algorithms to advanced LXM implementations in Java 17. Learn about algorithm performance, security considerations, and how to choose the right random number generator for your specific use case.

A comprehensive guide to understanding why MySQL queries slow down over time in sharded environments, exploring the underlying causes of storage fragmentation and MVCC-related issues, and providing practical solutions using table rebuilding techniques with OPTIMIZE TABLE for maintaining optimal database performance.

A deep dive into Java Memory Model (JMM) from specification to implementation, covering memory barriers, CPU reordering, and Java 9+ VarHandle APIs. Learn about coherence, causality, consensus, and how volatile, final, and other synchronization mechanisms work under the hood with practical jcstress examples.

Discover how enabling code location in logs can cause severe CPU performance issues in microservices, especially reactive applications. This deep-dive analysis reveals the hidden costs of stack walking in Log4j2 and provides actionable solutions for high-throughput systems.

An investigation into excessive memory allocation and YoungGC frequency after upgrading to Spring Boot 2.4.6 + Spring Cloud 2020.0.x, revealing how BeanUtils.copyProperties creates massive ResolvableType objects without caching in Spring 5.3.x versions.

A deep dive into MySQL’s InnoDB optimizer statistics and how sampling inaccuracies can lead to poor index selection, causing dramatic performance differences between similar queries. Learn practical solutions to prevent slow SQL queries caused by optimizer misjudgments.

When our operations team brought us a complex SQL query that was taking forever to execute, we thought it was just a performance issue. Little did we know, this investigation would uncover a deeply hidden character encoding mismatch that had been silently causing full table scans in our production database.