A Tale of Two XML Transformations
A few months ago we noticed unusually high CPU usage in one of our services. At first we didn’t take it seriously, but when we got a critical alert about 100% CPU utilization, we began to act. We ran top -H <service pid> in the troubled host and spotted a few threads that were using a CPU core each. Then we ran jstack <service pid> to get the thread stacks dump. The dump showed that all the threads in question were executing method transform of scala.xml.transform.RuleTransfo