C# - Distributed Critical Section In Web-farm?
Mar 18, 2011
I have about 50 web-sites, load-balanced across 5 web-servers. They all use Enterprise Library Caching, and access the same Caching database. The items in the Caching database are refreshed every few hours, using an ICacheItemRefreshAction implementation.I want to guarantee that only one web-site ever refreshes the cache, by putting the refresh code in a critical section. If the web-sites were running in a single app-pool on a single server, I could use a lock()If the web-sites were running in separate app-pools on a single server, I could use a Mutex.However, these will not ensure the critical section across multiple web-servers.Currently, I am creating a new key in the caching database to act as a mutex. This will generally work, but I can see a slim chance that 2 processes could enter the critical section.
public class TakeLongTimeToRefresh : ICacheItemRefreshAction
{
#region ICacheItemRefreshAction Members
[code]...
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