On October 11, 2021, GCeasy experienced an outage due to HTTP 504 errors caused by inefficiencies in a new SQL query from a recent deployment. AWS CloudWatch monitored CPU and database connection spikes, while yCrash identified the problematic code. Commenting out the SQL query restored application performance.
This article on chaos engineering demonstrates how to simulate a CPU spike to 100% using an infinite loop in a Java program with multiple threads. It discusses monitoring CPU consumption using the UNIX tool 'top' and suggests manual and automated root cause analysis methods, highlighting the yCrash tool's effectiveness in identifying the source of the issue.
In a study comparing memory consumption of Java threads, both dormant and active threads were found to consume the same memory, regardless of their activity level. The findings suggest that memory allocation occurs at thread creation, not based on usage, highlighting the importance of optimizing thread count and stack size in Java applications to reduce wasteful memory usage.