How do I update an expensive in-memory cache across a SharePoint farm?

Question

We have 3 front-end servers each running multiple web applications. Each web application has an in memory cache.

Recreating the cache is very expensive (>1 min). Therefore we repopulate it using a web service call to each web application on each front-end server every 5 minutes.

The main problem with this setup is maintaining the target list for updating and the cost of creating the cache several times every few minutes.

We are considering using AppFabric or something similar but I am unsure how time consuming it is to get up and running. Also we really need the easiest solution.

How would you update an expensive in memory cache across multiple front-end servers?

Answer 1

The problem with memory caching is that it's unique to the server. I'm going with the idea that this is why you want to use AppFabric. I'm also assuming that you're re-creating the cache every few minutes to keep the in memory caches in sync across all servers. With all this work, I can well appreciate that caching is expensive for you.

It sounds like you're doing a lot of work that probably isn't necessary. This article has some detail about the caching mechanisms available within SharePoint. You may be interested in the output cache discussed near the top of the article. You may also want to read the linked TechNet article and the linked article called "Custom Caching Overview".