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This guide explains how to locate the cause of sudden CPU spikes in a Java program by using the top command to identify the offending process and thread, converting the thread ID to hexadecimal, and analyzing stack traces with jstack to pinpoint the problematic code line.
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This article explains a three‑step method—using top to locate the CPU‑hungry Java process, identifying the offending thread, and printing its stack with jstack—to pinpoint and resolve excessive CPU consumption in a Java application running on Linux.
This guide explains how to use JDK command-line utilities such as jps, jstat, jinfo, jmap, jhat, and jstack to monitor JVM processes, inspect memory usage, generate heap dumps, and diagnose performance issues, providing command syntax, options, and practical examples.
This article explains how to locate Java deadlocks by using command‑line tools such as jps and jstack, the ThreadMXBean API’s findDeadlockedThreads method, and online utilities like FastThread and JStack Review, while also offering guidance on preventing and fixing deadlocks in production.
This article explains practical JVM tuning scenarios—including how to identify and resolve excessive CPU consumption, thread deadlocks, and memory leaks—by using Linux tools such as top, jstack, jps, jstat, and jmap, and by analyzing heap dumps with Eclipse MAT.
This article explains Java’s six thread states—NEW, RUNNABLE, BLOCKED, WAITING, TIMED_WAITING, and TERMINATED—provides detailed descriptions, shows how to inspect thread states using jstack and online tools, and includes example thread dumps for practical analysis.
This article introduces flame graphs, explains their visual characteristics and how they help identify performance bottlenecks in Java applications, and provides practical guidance on generating them using Perl scripts and shell commands to process jstack and perf outputs.
This article demonstrates how to combine Linux top with -H -p options and jstack to correlate Java thread IDs with their logical names, explains the underlying JDK thread‑naming bug, and provides practical recommendations for performance debugging on different JDK versions.
The article recounts a weekend on‑call incident where a Java monitoring service suffered network packet loss and a severe memory leak, leading to massive timeouts, high CPU usage, and frequent GC, and explains how the problem was diagnosed and resolved using tools such as top, jstat, jstack, jmap, and MAT.
This article introduces the jps tool for listing Java processes, explains its common options and usage examples, then provides a detailed overview of jstack, including its purpose, command syntax, thread‑state definitions, sample outputs, and practical tips for detecting deadlocks, counting threads, and diagnosing high CPU usage in Java applications.
This article explains the concept, features, and practical usage of flame graphs—including how to generate them from Java thread dumps with Perl scripts—to help developers visualize call‑stack frequencies and quickly identify performance bottlenecks in backend services.
This guide walks you through a step‑by‑step process using Linux top, jstack, and hex conversion to pinpoint the exact Java thread causing CPU spikes, enabling effective service optimization and cost reduction without unnecessary scaling.
This article explains how to identify and resolve intermittent high CPU usage in Java/Tomcat services by analyzing thread stacks with jstack, examining GC behavior with Jstat, and using Jmap for memory inspection, providing step‑by‑step commands and practical tips for ops engineers.
The article outlines practical techniques for debugging live Java systems, emphasizing comprehensive distributed logging, global exception handling, proactive JStack usage, BTrace tracing, and custom JVM agents to quickly identify and resolve production issues.