Caching Data in ASP.NET MVC 3

Question

I have an ASP.NET MVC 3 app that is basically just a set of web services. These web services are exposed by a set of Controller actions. Each controller action queries my database. Because my data rarely changes, and, stale data is not a concern, I thought i would implement some cacheing to improve performance. My goals are:

1. Never cache a response to a user.
2. Cache the database records for up to 24 hours. If 24 hours has passed, hit the database again.

Does that make sense? I know how to prevent the response from caching. I just use the following:

HttpContext.Response.Cache.SetCacheability(cacheability)

However, I'm not sure how to cache my database records in memory for up to 24 hours. Does anyone have any suggestions on how to do this? I'm not even sure where to look.

Thank you

Answer 1

You can use the System.Runtime.Caching namespace (or the ASP.NET cache, but this is older and can only be used within web applications).

Here's a sample function which you can use to wrap around your current data retrieval mechanism. You can alter the parameters in MemoryCache.Add to control how much it's cached, but you requested 24h above.

using System.Runtime.Caching;    // At top of file

public IEnumerable<MyDataObject> GetData() 
{
    IEnumerable<MyDataObject> data = MemoryCache.Default.Get(MYCACHEKEY) as IEnumerable<MyDataObject>;
    if (data == null)
    {
        data = // actually get your data from the database here
        MemoryCache.Default.Add(MYCACHEKEY, data, DateTimeOffset.Now.AddHours(24));
    }
    return data;
}

As mentioned by @Bond, you may also wish to look at using an SQL Cache Dependency if the data you're caching is likely to change within the 24 hours. If it's pretty static though, this will do what you asked.