How to initiate scheduling msg delivery

Question

Hi:
          I want to invoke a MDB every day at 22:00. The best way is to use Schedule class to deliver a same JMS msg to the MDB on my schedule.
          Now the question is when and where to initiate the scheduling?
          Is the start class in weblogic server the best place?
          Thanks,
          Tony

Answer 1

Hi Tony,
          I assume a startup class, or, likely more conveniently, a load-on-start-servlet, could be the right place, as long as it can reliably detect if there's already a scheduled timer (to avoid duplicate timers firing). Or perhaps a non-persistent scheduled message would suffice for your purposes, in which case there'd be no timer in the system when it boots.
          Side notes: When I look at scheduling of this nature, I worry about timer management first. Do the timers need to be easily canceled, paused, or modified? Will the timer still fire even if the server is booted a bit late - say 22:30? Pre 9.0 versions of WL don't provide the APIs necessary for JMS Scheduled message cancellation, pausing, or modification. The best place to initiate scheduling may actually be a UNIX cron job or NT Scheduled Task. Alternatively, WebLogic 9.0 provides persistent EJB timers that may suffice. And 9.2 will supply a "clustered timer" service (slightly less capable, but with higher HA characteristics).
          OK, I do run on a bit sometimes. Hope this helps.
          Tom, BEA