When Jenkins becomes unresponsive, it can significantly impact development timelines. This article discusses common symptoms, causes, and solutions for both Jenkins controllers and agents. Issues may arise from resource exhaustion, locking problems, or slow external services. Regular monitoring and diagnostic tools like yCrash can expedite troubleshooting and prevent future outages.
Java Flight Recorder (JFR) enables continuous profiling of applications by capturing runtime execution data within the JVM. This blog explores Network Lag, a performance issue caused by delays in network responses, impacting application performance. It discusses simulation, capturing JFR data, and analyzing it using yCrash JFRPlayer to identify and resolve the underlying delays effectively.
Java Flight Recorder (JFR) allows for low-overhead profiling to identify performance issues like DB connection leaks. This occurs when applications fail to close database connections, exhausting limits and causing errors. The blog outlines how to simulate and analyze connection leaks using JFR data, providing methods for resolution, including proper resource management practices.
The blog discusses the Java Flight Recorder (JFR) and its role in profiling performance issues, specifically Heavy I/O, caused by excessive file read/write operations from multiple threads that exhaust disk capacity. It details the simulation of this issue, captures JFR data for analysis, and suggests solutions to mitigate Heavy I/O problems.
Java Flight Recorder (JFR) enables low-overhead profiling within the JVM, capturing execution samples. This blog discusses StackOverflowError, typically caused by excessive recursion or cyclic class constructions. By simulating the error, we illustrate its causes and demonstrate JFR's use in troubleshooting. Solutions include adding termination conditions and converting recursion to iteration.
Java Flight Recorder (JFR) enables low-overhead profiling within the JVM, highlighting performance issues like deadlock. Deadlock occurs when threads wait indefinitely for each other to release resources. The blog discusses simulating deadlock, capturing JFR data for analysis using yCrash JFRPlayer, and suggests solutions, including consistent lock ordering and avoiding nested locks.
Java Flight Recorder (JFR) enables efficient profiling by capturing runtime execution in the JVM. The issue of Thread Leak arises when threads are created but not terminated, consuming memory and eventually leading to java.lang.OutOfMemoryError. This blog explores simulation of the problem, troubleshooting via JFR data, and potential fixes for the leak.
Java heap dumps are crucial for troubleshooting memory issues in JVM applications. The recent yCrash webinar highlighted Object Query Language (OQL) as a powerful tool to analyze heap dumps efficiently through SQL-like queries. It discussed OQL's syntax, advanced features, and practical use cases for identifying memory leaks and optimizing performance.
Java garbage collection (GC) operates silently, but when overloaded, it severely impacts Jenkins performance, causing build stalls and memory-related errors. By identifying symptoms such as slow builds and high CPU usage, admins can diagnose issues through GC logs and heap dumps. Proper tuning and monitoring can prevent and resolve GC problems efficiently.
Java Flight Recorder (JFR) enables low-overhead profiling to diagnose CPU spikes, which occur when threads excessively consume CPU resources, often due to infinite loops or inefficient code. This blog outlines causes, simulates the issue, captures JFR data, and analyzes it to identify performance bottlenecks, specifically within the CPUSpikerThread class.
