How to use Quartz scheduler to send email when an auction closes

yes you can do that, have a read thru here

http://www-128.ibm.com/developerworks/java/library/j-quartz/

Don't forget to create your schedules both when a new auction is created, and also when app starts.

05.15.2008 at 02:21AM PDT, ID: 21571733

Rank: Genius

Such a solution won't scale well. The most efficient way would probably be to set up a trigger in the database

05.15.2008 at 04:03AM PDT, ID: 21572229

Why do you say it wont scale well and how do I set a trigger in the database. I thought database triggers cannot be used here.

05.15.2008 at 04:12AM PDT, ID: 21572293

Rank: Genius

>>Why do you say it wont scale well

Because the more auctions you have, the more running timers you'll have

>>I thought database triggers cannot be used here.

That would depend on the db you have. What is it?

05.15.2008 at 04:19AM PDT, ID: 21572326

Rank: Genius

> Why do you say it wont scale well and how do I set a trigger in the database. I thought database triggers cannot be used here.

It'll scale just fine. Quartz can handle a very large number of schedules
We've never had a problem with it.

05.15.2008 at 04:56AM PDT, ID: 21572493

I'm using Mysql database.

That thought did occur my mind about the number of timers - Good to know from Objects that Quartz can handle a large number.

This is the other approach I had in mind:
1) Schedule a job in Quartz to run once every hour. This job will look for auctions expiring in that hour. Say for example, its looking for auctions that expire between 10:00 AM and 11:00 AM. And we have three groups expiring - one at 10:10AM, second at 10:27AM and the third at 10:45 AM.
2) Now for these 3 groups - we will schedule 3 seperate one time jobs to execute at 10:10,10:27 and 10:45 to send out emails for the respective groups

What do you guys think of this approach?

05.15.2008 at 05:00AM PDT, ID: 21572514

Rank: Genius

I wouldn't overcomplicate unless you find a need to. Keep it simple initially :)
Quartz's job is to handle the sceduling, so don't bother yourslf unecessarily with scheduling that quartz is designed for.

05.15.2008 at 05:01AM PDT, ID: 21572521

Rank: Genius

The number of timers Quartz can handle is not really the point. It's simply not a particularly efficient way of doing things if another way, such as triggers, can be found

05.15.2008 at 05:10AM PDT, ID: 21572588

Rank: Genius

Sadly, in this case, it's academic - MySQL doesn't support external calls from triggers

05.15.2008 at 05:30AM PDT, ID: 21572733

Objects - I'm just thinking that if an auction is going to close in 7 days - then we kick off the scheduler - but during these 7 days time - if for some reason the server crashes and needs to be restarted - we have to persist the job information.

But in the approach I suggested - we wont have to worry about that - we can build the logic that the job that runs every hour - can also check which auctions that expired earlier but had not sent the emails bcos of server crash or something and send them out as well.........

CEHJ - Are you suggesting that I can create triggers in Mysql - to see which auctions have expired. I've never come across creating triggers for this purpose. Can you explain how this can accomplished via triggers

thanks

05.15.2008 at 05:33AM PDT, ID: 21572760

Rank: Genius

>>
What I mean is if the auction is created to close in one day - at the time of creating the auction - start a timer that starts counting down from 24 hours. When the timer reaches zero - we know the auction has expired - and then send out the emails.
>>

>>
1) Schedule a job in Quartz to run once every hour. This job will look for auctions expiring in that hour. Say for example, its looking for auctions that expire between 10:00 A .....
>>

The most efficient way if you're going to use the scheduler is to schedule one-time jobs in each case. When the task is due for execution, make it check in the db that the auction has not been cancelled in some way just prior to sending the mail. You can integrate the sending of the mail with your logging by using an SMTPAppender

05.15.2008 at 05:33AM PDT, ID: 21572764

ok atleast one option is closed for me now :)

05.15.2008 at 05:35AM PDT, ID: 21572780

Rank: Genius

> f for some reason the server crashes and needs to be restarted - we have to persist the job information.

as i mentioned earlier, you just initialze your schedule on startup.
Plus quartz supports persistence,

And steer clear of db triggers, they'll just cause u a world of hurt down the track.

Accepted Solution

05.15.2008 at 05:43AM PDT, ID: 21572880

Rank: Genius