Facebook顶级共享URL，按用户间隔更新，MySQL选择更新

Question

I know the title is complicated, but i was looking for some advise on this and found nothing.

Just want to ask if i'm thinking the right way.

I need to make a top facebook shared page with about 10 items or so for my website items (images, articles etc.)

And this is simple, i will just get the share count from facebook graph api and update in database, i don't want to make it in some ajax call based on fb share, it could be misused.

Every item has datetime of last update, create date and likes fields in database.

I will also need to make top shared url in 24h, 7 days and month so the idea is simple:

1. User views an item, every 10 minutes the shared count is obtained from fb graph api for this url and updated in database, database also stores last update time.
2. Every time user is viewing the item, the site checks last update datetime, if it is more than 10 minutes it makes fb api call and updates. It is every 10 minutes to lower fb api calls.

This basically works, but there is a problem - concurrency.

When the item is selected then in php i check if last update was 10 minutes ago or more, and only then i make a call to fb api and then update the share count (if bigger than current) and rest of data, because a remote call is costly and to lower fb api usage.

So, till users view items, they are updated, but the update is depending on select and i can't make it in one SQL statement because of time check and the remote call, so one user can enter and then another, both after 10 minutes and then there is a chance it will call fb api many times, and update many times, the more users, the more calls and updates and THIS IS NOT GOOD.

Any advise how to fix this? I'm doing it right? Maybe there is a better way?

Answer 1

You can either decouple the api check from user interaction completely and have a separate scheduled process collect the facebook data every 10 minutes, regardless of users

Or, if you'd rather pursue this event-driven model, then you need to look at using a 'mutex'. Basically, set a flag somewhere (in a file, or a database, etc) which indicates that a checking process is currently running, and not to run another one.