Install Jstack On Ubuntu

“Unable to open socket” or “No such process”

Permission denied / cannot attach

Incompatible jstack / JVM versions

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ps aux | grep java
# or
jps -l

# Remove OpenJDK 11
sudo apt remove openjdk-11-jdk
| Issue | Solution |
|-------|----------|
| jstack: command not found | JDK not installed or not in PATH |
| Operation not permitted | Run with sudo or the same user as the Java process |
| Unable to open socket file | Java process may be using a different JVM (e.g., IBM, GraalVM) |
| PID not found | Process not running or you don't own it |