28491 org.apache.catalina.startup.Bootstrap 29502 sun.tools.jps.Jps Use code with caution. In this scenario, 28491 is the PID for a Tomcat web server. 2. Generate a Thread Dump on Screen
On Ubuntu 10.10 and later, the system imposes restrictions on the ptrace(2) system call, which can cause jstack (along with jinfo and jmap) to fail with permission errors when running as a non‑root user. Throughout this guide, you will find solutions to address this issue, including running with sudo or adjusting system security settings.
Since jstack is part of the JDK, we need to verify what Java packages are installed:
After installation, you can generate a thread dump for a running Java process using its Process ID (PID): CloudBees Docs Find the Java PID: ps -e | grep java Run jstack: jstack > thread_dump.txt with the actual number found in step 1) How to install jstack on Redhat 8 - Atlassian Community install jstack on ubuntu
On Ubuntu, jstack is not installed by default—only the Java Runtime Environment (JRE) usually is. To get jstack , you must install the , not just the JRE.
Because jstack is part of the JDK (not the JRE), you cannot simply install it as a standalone package; you must install the full Java Development Kit.
This is a known issue on Ubuntu 10.10 and later due to default ptrace restrictions. 28491 org
jstack requires the Process ID of the running Java application. You can find this using jcmd (which is also installed with the JDK) or ps .
user wants a long article on how to install jstack on Ubuntu. I need to provide a comprehensive guide covering installation methods, prerequisites, usage examples, and troubleshooting. I'll need to search for relevant information. search results provide some relevant links. I'll open them to gather detailed information. search results provide good information on installing jstack via JDK, usage examples, and troubleshooting. I'll also need to cover the ptrace permission issue. I'll structure the article with an introduction, prerequisites, installation methods (including Docker), verification, usage examples (basic, with options), troubleshooting common issues (command not found, permission denied, etc.), and best practices. I'll cite relevant sources. How to Install and Use jstack on Ubuntu: A Comprehensive Guide
jstack -version
OpenJDK 17 is the more recent LTS version and is often the default choice for new projects.
If your Java process is running as the tomcat or www-data user, you must run jstack as that user using sudo : sudo -u tomcat jstack 12345 > thread_dump.txt Use code with caution.
/usr/lib/jvm/java-17-openjdk-amd64/bin/jstack -version Generate a Thread Dump on Screen On Ubuntu 10