Chronic
Chronic is a constraints-based opportunistic application-level scheduler. Unlike cron, which schedules according to a time specification, it schedules tasks when specified constraints are met. In other words, it schedules during a window of opportunity when the circumstances are favorable.
| Tags | Systems Administration Monitoring |
|---|---|
| Licenses | Artistic |
| Operating Systems | POSIX Linux |
| Implementation | Perl |
Recent releases
- 26 Apr 2005 11:18
Changes: "Ping" constraint was introduced. The constraint sends a single ICMP ping to a given address, and is considered met if an ICMP packet is successfully received. "Concurrent'' constraint was introduced. The constraint keeps a tab on the number of concurrent processes of a specified application. A "safe_sleep'' time was introduced at the end of the scheduler's while() loop. This stops the scheduler to go into a tight loop every time there are a few microseconds of latency between task_wait and Freq constraint.
- 18 Aug 2004 18:41
Changes: Syslog support has been introduced. SIGHUP handling has been augmented to defer signals during task execution, since tasks can't be safely interrupted. The scheduling algorithm has been improved. emerge-later, an application which adds packages to be emerged (using Gentoo's package manager, emerge) to the system crontab as only_once tasks, has been added to the distribution.
- 30 Jun 2004 20:19
Changes: SIGHUP handling was introduced in chronicd. On receipt of a HUP signal, chronicd will drop the existing schedule, re-read config files, and start over again. The capability to run certain tasks "only once" was added to the Scheduler. Notification functionality was augmented to inform the user of failures.
- 04 Jun 2004 23:28
Changes: An "InXs" constraint that combines the Inactivity constraint and the Xscreensaver constraint using an OR relationship was included. The scheduler wait behaviour was changed and now waits for a maximum of 10 minutes to avoid lost time due to hibernation or suspension of processes. Support for email notifications for successfully scheduled tasks was implemented. Some minor bugs were fixed and more documentation was added.
- 15 May 2004 21:38
Changes: This release contains some bugfixes and a new "Xscreensaver" constraint, that is met when Xscreensaver stays locked or blanked for a specified amount of time.
