基于百分比的高流量套装？

Question

The setup: High traffic website and a list of image URLs that we want to display. We have one image spot, and each item in the set of image URLs has a target display percentage for the day. Example:

• Image1 - 10%
• Image2 - 30%
• Image3 - 60%

Because the traffic amount can vary from day to day, I'm doing the percentages within blocks of 1000. The images also need to be picked randomly, but still fit the distribution accurately.

Question: I've implemented POC code for doing this in memcache, but I'm uncomfortable with the way data is stored (multiple hash keys mapped by a "master record" with meta data). This also needs to be able to fall back to a database if the memcache servers go down. I'm also concerned about concurrency issues for the master record.

Is there a simpler way to accomplish this? Perhaps a fast mysql query or a better way to bring memcache into this?

Thanks

Answer 1

A hit to the database is most likely going to take longer so I would stick with memcache. You are going to have more issues with concurrency using MySQL than memcache. memcache is better equipped to handle a lot of requests and if the servers go down, this is going to be the least of your worries on a high traffic website.

Maybe a MySQL expert can pipe in here with a good query structure if you give us more specifics.