[KARAF-2552] Running log:tail on admin:console causes full CPU usage.

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 2.3.3
• Fix Version/s: 2.4.0, 3.0.0, 2.3.4
• Component/s: karaf

Environment

Mac OS X on java version "1.7.0_45" and java version "1.6.0_65"
Windows 7 on java version "1.6.0_41"

• Assignee: Freeman Fang
• Reporter: Mateo Ramey
• Created: 07/Nov/13 19:04
• Updated: 15/Sep/18 16:35
• Resolved: 14/Nov/13 01:37

Description

Running log:tail on the admin console causes 100% cpu usage. There were no logs being shown during the tail, just simply running the tail is causing the CPU to spike up.

Steps to reproduce:
1) Download Karaf 2.3.3 distribution.
2) Start karaf
3) run log:tail command
4) Watch CPU monitor (top in *nix or task manager in windows) show full cpu usage
5) ctrl-c out of log:tail and CPU usage goes back to idle.

Attaching a profiler to Karaf identified the method taking up CPU as:
org.apache.karaf.shell.console.jline.DelayedStarted.run()

Not sure if that is fully accurate, but might be a place to start.

Note: Was unable to reproduce issue on Karaf 2.3.2 and as a result we have had to revert back to that version.

Let me know if you have any additional questions.

Thanks!