How should I complete this type of notification?

I am basically creating a site for recruiters. One of the functionality in my application requires 开发者_运维百科posting to Facebook periodically. The posting frequency can be from 0(Never) to 4(High)

For Eg. If a recruiter has 4 open jobs and he has posting frequency set to 4, each job should be posted as per it's turn: 1st job on 1st day, 2nd job on 2nd, 3rd job on 3rd etc, on 5th day again 1st job (round robin fashion).

Had he set the posting frequency to 2, two jobs would be posted daily (thus each job would be posted every 2 days)

My only question is what type of threading should I create for this since this is all dynamic!! Also, any guidelines on what type of information should I store in database?

I need just a general strategy to solve this problem. No code..

• I think you need to seperate it from your website, I mean its better to run the logic for posting jobs in a service hosted on IIS ( I am not sure such a thing exists or not, but I guess there is).
• Also you need to have table for job queue to remember which jobs need to be posted, then your service would pick them up and post them one by one.
• To decide if this is the time for posting a job you can define a timer with a configurable interval to check if there is any job to post or not.
• Make sure that you keep the verbose log details if posting fails. It is important because it is possible that Facebook changes its API or your API key becomes invalid or anything else then you need to know what happened.
• Also I strongly suggest to have a webpage for reporting the status of jobs-to-post queue, if they failed what was the causes of problem.

If you program runs non-stop, you can just use one of the Timer classes available in .NET framework, without the need to go for full-blown concurrency (e.g. via Task Parallel Library).

I suspect, though, that you'll need more than that - some kind of mechanism to detect which jobs were successfully posted and which were "missed" due program not running (or network problems etc.), so they can be posted the next time the program is started (or network becomes available). A small local database (such as SQLite or MS SQL Server Compact) should serve this purpose nicely.

If the requirements are as simple as you described, then I wouldn't use threading at all. It wouldn't even need to be a long-running app. I'd create a simple app that would just try to post a job and then exit immediately. However, I would scheduled it to run once every given period (via Windows Task Scheduler).

This app would check first if it hasn't posted any job yet for the given posting frequency. Maybe put a "Last-Successful-Post-Time" setting in your datastore. If it's allowed to post, the app would just query the highest priority job and then post it to Facebook. Once it successfully posts to Facebook, that job would then be downgraded to the lowest priority.

The job priority could just be a simple integer column in your data store. Lower values mean higher priorities.

Edit:

I guess what I'm suggesting is if you have clear boundaries in your requirements, I would suggest breaking your project into multiple applications. This way there is a separation of concerns. You wouldn't then need to worry how to spawn your Facebook notification process inside your web site code.