Troubleshooting

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.

An in-depth investigation into mysterious JVM safepoint delays after upgrading to Java 17 and implementing centralized log collection with AWS EFS. We discovered how file I/O blocking during log output can freeze entire JVM processes and solved it using async logging and proper WebFlux implementation.

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.

A deep dive into a mysterious production issue where exception logs mysteriously disappeared, leading us through Arthas debugging, Log4j2 internals, and the discovery that an exception’s getMessage() method was itself throwing exceptions due to Guava-Guice version incompatibility.

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.