I am working on a site where I will need to be able to track ad impressions. My environment is ASP.Net with IIS using a SQL Server DMBS and potentially Memcached so that there are not as many trips to the database. I must also think about scalability as I am hoping that this application becoming a global phenom (keeping my fingers crossed and working my ass off)! So here is the situation:
- My Customers will pay X amount for Y Ad impressions
- These ad impressions (right now, only text ads) will then be shown on a specific page.
- The page is served from Memcached, lessening the trips to the DB
- When the ad is shown, there needs to be a “+1” tick added to the impression count for the database
So the dilemma is this: I need to be able to add that “+1” tick mark to each ad impression counter BUT I cannot run that SQL statement every time that ad is loaded. I need to somehow store that “+1” impression count in the session (or elsewhere) and then run a batch every X minutes, hours, or day.
Please keep in mind that scalability is a huge factor here. Any advice that you all have would be greatly appreciated.
I’ve seen projects deal with this by deploying SQL Server Express edition on each web farm server and relying on Service Broker to deliver the track audit to the central server. Because each server in the farm updates a local SQL instance, they can scale as high as the sky. Service Broker assures the near-real-time reliable delivery. I’ve seen web farms handle 300-400 requests per second on average, 24×7 over long time, and with the queued nature of Service Broker being able to absorb spikes of 5000-7500 hits per second for hours at end, and recover in reasonable time, without audit loss and with the backlog staying under control.
If you really expect to scale and become the next MySpace, then you should learn from how they do it, and queue based asynchronous, decoupled processing is the name of the game.