iisExpress local httpruntime.cache always null

Question

strange problem here. On local development in asp.net webforms (4.5 / 4.7) I am finding httpruntime.Cache always null even when properly set. I attempted it on another iis express workstation and found the same behavior, even with a tester single page web page. That same page in production IIS 7.5 works and is storing and delivering from cache. The code specifically is below, but I have tried a tester storing a simple string in httpruntime.Cache.

var cache = System.Runtime.Caching.MemoryCache.Default;
var luCacheKey = "lu_" + dsName;

var ic = HttpRuntime.Cache.Get(luCacheKey) as ICollection;
if (ic == null) {

and from the tester

var item = HttpRuntime.Cache.Get("x");
if (item == null)
{
    HttpContext.Current.Cache.Insert("x", "test" , null, DateTime.Now.AddHours(1), Cache.NoSlidingExpiration);
    Response.Write("added to cache<br>");
}
else {
    Response.Write("already in cache");
}

So, I am wondering if there is something perhaps in web.config that I could look at or is this expected IIS express behavior? Note, System.runtime.Caching does work properly.

var cache = System.Runtime.Caching.MemoryCache.Default;
var ic = cache[luCacheKey] as ICollection;
if (ic == null)
{
var filterCriteria = new BinaryOperator("LookupGroup", dsName, BinaryOperatorType.Equal);
var lookups = xpoSession.GetClassInfo(typeof(Lookups));
ic = xpoSession.GetObjects(lookups, filterCriteria, new SortingCollection(), 0, 0, false, false);
var cachePolicy = new System.Runtime.Caching.CacheItemPolicy() { AbsoluteExpiration = DateTime.Now + TimeSpan.FromMinutes(30) };
cache.Add(new System.Runtime.Caching.CacheItem(luCacheKey, ic), cachePolicy);

Answer 1

You incorrectly add your object to the cache.

Instead of DateTime.Now follow the docs and put DateTime.UtcNow. This resolves a common issue where your machine is in a "non-zero" time zone which prevents the inner logic of the cache to manage your expirations correctly.

From the docs

To avoid possible issues with local time such as changes from standard time to daylight saving time, use UtcNow rather than Now for this parameter value.

https://msdn.microsoft.com/en-us/library/4y13wyk9(v=vs.110).aspx