After upgrading to Sitecore 8.2 Update-5 recently I was looking in our CD server's logs and noticed a large number of warnings around the AccessResultCache:
7792 14:52:05 WARN AccessResultCache cache is cleared by Sitecore.Caching.Generics.Cache'1+DefaultScavengeStrategy[[Sitecore.Caching.AccessResultCacheKey, Sitecore.Kernel, Version=10.0.0.0, Culture=neutral, PublicKeyToken=null]] strategy. Cache running size was 8.8 MB.
7792 14:52:05 WARN AccessResultCache cache is cleared by Sitecore.Caching.Generics.Cache'1+DefaultScavengeStrategy[[Sitecore.Caching.AccessResultCacheKey, Sitecore.Kernel, Version=10.0.0.0, Culture=neutral, PublicKeyToken=null]] strategy. Cache running size was 9 MB.
7792 14:52:05 WARN AccessResultCache cache is cleared by Sitecore.Caching.Generics.Cache'1+DefaultScavengeStrategy[[Sitecore.Caching.AccessResultCacheKey, Sitecore.Kernel, Version=10.0.0.0, Culture=neutral, PublicKeyToken=null]] strategy. Cache running size was 9 MB.
7792 14:52:05 WARN AccessResultCache cache is cleared by Sitecore.Caching.Generics.Cache'1+DefaultScavengeStrategy[[Sitecore.Caching.AccessResultCacheKey, Sitecore.Kernel, Version=10.0.0.0, Culture=neutral, PublicKeyToken=null]] strategy. Cache running size was 9 MB.
7792 14:52:06 WARN AccessResultCache cache is cleared by Sitecore.Caching.Generics.Cache'1+DefaultScavengeStrategy[[Sitecore.Caching.AccessResultCacheKey, Sitecore.Kernel, Version=10.0.0.0, Culture=neutral, PublicKeyToken=null]] strategy. Cache running size was 9 MB.
7792 14:52:06 WARN AccessResultCache cache is cleared by Sitecore.Caching.Generics.Cache'1+DefaultScavengeStrategy[[Sitecore.Caching.AccessResultCacheKey, Sitecore.Kernel, Version=10.0.0.0, Culture=neutral, PublicKeyToken=null]] strategy. Cache running size was 9 MB.
7792 14:52:06 WARN AccessResultCache cache is cleared by Sitecore.Caching.Generics.Cache'1+DefaultScavengeStrategy[[Sitecore.Caching.AccessResultCacheKey, Sitecore.Kernel, Version=10.0.0.0, Culture=neutral, PublicKeyToken=null]] strategy. Cache running size was 9 MB.
Before upgrading and reverting back to the (in some cases new) default cache sizes, we had Caching.AccessResultCacheSize
set to 2MB, and don't see this cache clearing message.
Looking into this further it appears that on CD server's we can set the size to 0 if we're not using it, but I'm not sure of the best way to determine if we have legacy code that is relying upon this, or if we have any content that may be restricted.
What's the best way to determine if Caching.AccessResultCacheSize
can be set to 0 on a CD server? And is there a reason we might be seeing this message more with a larger cache size, after upgrading from 7.2.current?