The article discusses an unexpected memory leak issue caused by Java's ThreadPoolExecutor, which results in "java.lang.OutOfMemoryError". Despite executing 10 jobs with 5 worker threads, the threads remain in memory instead of being garbage collected. The solution is to call the executor's shutdown() method to properly terminate the threads after job execution.
The ConFoo.CA Developer Conference, a major event for programmers, is now fully virtual, featuring over 100 presentations by international speakers. Architect Ram Lakshmanan will present on "7 JVM Arguments of Highly Effective Applications," focusing on key arguments that can significantly enhance application performance amidst the complexity of over 600 options available.
This article explores the simulation of the 'java.lang.OutOfMemoryError: Java Heap space' in Java applications. It presents a sample program that continuously adds records to a HashMap until the heap size is exceeded, causing the error. The post discusses both manual and automated approaches to troubleshoot this issue effectively.
The study reveals that Java threads, regardless of their active or dormant states, consume equivalent memory upon creation. Testing with two programs demonstrated that both empty and full stack frame threads allocated the same memory. Developers are advised to minimize thread creation and optimize stack sizes to reduce memory waste.
This article explains how to simulate 100% CPU consumption using an infinite loop in multiple threads with Java's BuggyApp application. It details the implementation of the 'CPUSpikeDemo' and 'CPUSpikerThread' classes. The author also suggests methods for diagnosing spikes, including manual thread dumps and automated analysis tools like yCrash for root cause identification.
Unix/Linux processes can be in various states: RUNNING & RUNNABLE, INTERRUPTABLE_SLEEP, UNINTERRUPTABLE_SLEEP, STOPPED, and ZOMBIE. Each state indicates a different condition of process activity and resource waiting. The article also explains how to terminate processes in different states and methods to find their current state using command-line tools.
This article provides an overview of various methods to terminate processes in Unix/Linux systems. It explains commands like 'kill', 'killall', and 'pkill', detailing how to use them effectively. The 'top' command is also discussed for process termination. Key differences between these commands are highlighted for user clarity.
Load average is a key metric from the 1970s indicating system load levels over intervals of 1, 5, and 15 minutes. It reveals trends in compute demand, factoring in CPU, file I/O, and network demands. A load above 80% warrants investigation, while a relative interpretation determines its significance across applications.
The 'Load Average' metric, often mistaken as solely CPU demand, also reflects I/O demand. A case study using BuggyApp demonstrated this, showing high disk I/O operations led to a Load Average of 5.0 on a single CPU system, despite low CPU utilization. Thus, Load Average encompasses both CPU and I/O activity.