MySQL Bugs: #34389: event sched. spawns new event while a previous instance of it is still runing

Bug #34389	event sched. spawns new event while a previous instance of it is still runing
Submitted:	7 Feb 2008 18:12	Modified:	8 Feb 2008 19:24
Reporter:	Robert Hamel	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: Stored Routines	Severity:	S4 (Feature request)
Version:	5.1.22-rc-log	OS:	Linux
Assigned to:		CPU Architecture:	Any

Description:
I have a few events that are scheduled to run every minute.  The scheduler will launch a new instance of the event even though there is one already running which simply duplicates cron.

I was expecting a "don't start a new one until the previous one is finished" behaviour

How to repeat:
create a proc with an that updates a row in a table and commits.  

Schedule it to run every minute

update that row on the command line and just wait

Suggested fix:
If that is the intended functionality then you might want to mention that in the documentation but I would either make the default behavior: "don't start a new one until the old one is finished" or at least give the ability to specify that behavior in the create event syntax.

Thank you for the feature request.

Although you can easily implement such functionality in the event itself.

Thanks for the update....and yes I added get_lock and release_lock to get around the problem...but I wasn't expecting that behavior