Object Caching using C# in CRM Online

Question

I am using Object Caching in C# to store an EntityCollection in Cache.

Following is the code for caching :

ObjectCache cache = MemoryCache.Default;
const string keyName = "BrandPartners";
EntityCollection result;

if (!cache.Contains(keyName))
{
    result = GetCustomerData(service, firstName, lastName, gender);
    var cacheItemPolicy = new CacheItemPolicy()
    {
        AbsoluteExpiration = DateTime.Now.AddMinutes(5)
    };

    tracingService.Trace("Writing into the cache");
    cache.Add(keyName, result, cacheItemPolicy);
}
else
{
    result = (EntityCollection)cache.Get(keyName);
    tracingService.Trace("Data already found in the cache");
}

So, when I am first creating a record in an entity in an instance in CRM online, I am getting the trace : "Writing into the cache."

But, when I am again creating a record in the same entity, I am again getting the same trace ("Writing into the cache"). But, if I am using caching, I should not get this trace because the keyName of "BrandPartners" already exist in the cache.

So, what am I doing wrong?

Answer 1

Here are some possible reasons why you're not seeing a cached value being found:

• You're on CRM online, or on-prem and have load balancing in place. The Memory Cache is obviously only for a single process on a single machine.
• The Workflow activity is registered for multiple workflows/entities, in sandbox mode. In this case, each and every instance of the registration would get a separate sandbox process, and therefore would have separate Memory Caches
• CRM decided to refresh the plugin sandbox process. This happens from time to time to avoid memory leaks, so this may be the case as well.