Bret, Thanks for sharing, we appreciate it! -MC On Fri, Oct 23, 2009 at 11:43 AM, Trixter aka Bret McDanel < trixter@0xdecafbad.com> wrote:
for anyone that is interested, in <SRC>/contrib/trixter/scheduled_event.lua there is a script, which admittedly is not very well tested (written last night) that allows for mysql events to be scheduled to be run.
Why mysql and not sched_api or similar? Well this allows the scheduled events to survive past a reboot, shutdown, crash, alien abduction, or other issue. It also is written in a way to allow for many switches to each pull an event off one at a time and process them, thus distributing the load. sched_api requires that the scheduled event exist on a particular switch which can be a bit messy in some applications.
So you can do a "hotel style wake up call" (good for getting out of boring meetings or bad blind dates) or really anything you want.
You can start/stop the script, even change the DB credentials without a restart to allow for easier load management or maintenance.
Its a trivial script, but I didnt see anything like this elsewhere. If people have specific feature requests (like adding a machine column to the table so that certain events can be scheduled only for specific machines, or only pulling events when the load is under X) let me know and I will look into doing that.
The only problem that I saw last night was that it runs every "heartbeat" (FS eventing system) and if you have more tasks to accomplish in a given interval it can get a little backlogged and does not do any notification to that effect.
-- Trixter http://www.0xdecafbad.com Bret McDanel pgp key: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8AE5C721