Your Java application has been running fine, but all of a sudden CPU consumption starts to go higher and higher until it stays at 80 - 100%. Even if you remove the server from load balancer (so that traffic isn’t sent... Continue Reading →
Thread dumps are vital artifacts to diagnose CPU spikes, deadlocks, poor response times, memory problems, unresponsive applications, and other system problems. There are great online thread dump analysis tools such as http://fastthread.io/, which can analyse and spot problems. But to... Continue Reading →
Learn about JVM Internals in just 3 crisp slides. Deck talks about JVM Architecture; it's memory model and Garbage Collection process succinctly in 3 slides.
Description If threads are blocking momentarily, then it’s not a problem. However, if they are blocking for a prolonged period, then it’s of concern. It's indicative of some problem in the application. Typically blocked threads would make application unresponsive. Threads... Continue Reading →
Description You might have experienced the application’s CPU to spike up suddenly & spike wouldn’t go down until JVM is recycled. You restart the JVM, after certain time period CPU consumption would once again start to spike up. Then you will have to... Continue Reading →
Description Thread-A could have acquired the lock-1 and then would never release it. Thread-B could have acquired lock-2 and waiting on this lock-1. Thread-C could be waiting to acquire lock-2. This kind of transitive blocks between threads can make entire application unresponsive. See the real-world... Continue Reading →
Description When there is a performance bottleneck in the application, most of the threads will start to accumulate on that problematic bottleneck area. Those threads will have same stack trace. Thus whenever a significant number of threads exhibit identical/repetitive stack trace then those... Continue Reading →
Description If several threads in a thread dump end up working on one single method, then it might be of concern. Most of the times, if there is a problem (say poorly responding data source, un-relinquished lock, infinite looping threads... Continue Reading →