Should I create a new quartz job and trigger or one job and many triggers?

Question

I am looking to use quartz to schedule emails, but I'm not sure which approach to take:

1. Create a new job and trigger whenever an email is scheduled OR
2. Create a single job, and create a new trigger each time an email is scheduled

I need to pass the message/recipient etc either way, and I'm not sure whether creating heaps of jobs will start adding considerable memory overheads, as there will quite possibly be thousands of emails scheduled.

Update: These emails will be scheduled by users, not by me - so I will be adding these programmatically at runtime, they aren't scheduled to go out at any particular time.

Answer 1

You might consider queuing or otherwise grouping a set of emails and have a single, or maybe a few, periodic (or scheduled) job(s) that then takes care of the 'batch'.

You could even have the Quartz job queue the emails for a collection of workers to consume and send.

I would not recommend thousands of Quartz jobs/triggers - it just isn't the intended use of the tool (IMHO).

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EDIT: In response to the comment below:

I would not recommend thousands of Quartz jobs/triggers when used as part of a framework executing an application in the same JVM, The jobs/triggers will be competing for resources with the rest of the application.

Answer 2

Are the triggers to be based on a time schedule? You can use a CronTrigger to set up a more complex time based schedule rather than individual triggers.

Answer 3

I'd recommend one job and one trigger. Put the email requests in a database table and have the quartz job look for new emails to send.