Seeing `CMS: abort preclean due to time` in the gc.log; is this a cause for concern?
Environment
- Red Hat Enterprise Linux
- 5.x
- 6.x
- Java instances using the CMS collector.
Issue
- Seeing
CMS: abort preclean due to timein the gc.log; is this a cause for concern?
Resolution
- The CMS collector goes through the following phases, only two of which are stop-the-world:
CMS initial mark - stop-the-world phase
CMS marking
CMS precleaning
CMS abortable preclean
CMS Remark - stop-the-world phase
CMS sweep
CMS reset
The error message above is printed if the abortable preclean phase exceeds the CMSMaxAbortablePrecleanTime, which defaults to 5 seconds. If this is exceeded it then aborts this phase and continues to the next, which is a stop-the-world.
- If this message is repeatedly printed then it indicates that it is unable to complete the preclean phase in 5 seconds. Either the time needs to be increased to allow for a longer preclean phase, or the OS or heap needs to be examined to determine why this is not completing in the 5 seconds allotted.
This solution is part of Red Hat’s fast-track publication program, providing a huge library of solutions that Red Hat engineers have created while supporting our customers. To give you the knowledge you need the instant it becomes available, these articles may be presented in a raw and unedited form.
Welcome! Check out the Getting Started with Red Hat page for quick tours and guides for common tasks.
