I thought I understood how the module caching works but I'm coming across a confusing situation. My understanding was that if module caching is turned on, then during the cache period the html for the module would be returned from cache and displayed instead of executing the module again.

I've been finding that it doesn't seem to work this way at all. Perhaps I'm misunderstanding something here, I'm not sure.

Here's how I've investigated this. I put a single html module on the home page, and set the cache time to 60 seconds for this module. I started up SQL Profiler to start a trace for the database and then started to refresh the page manually using F5. Even though the cache time is set to 60 seconds, the database still gets hit each time with the command:

exec dbo.DNN_GetHtmlText @ModuleId = 347

which is the command used to get the html text for the module. If the module is truly cached, why is it still executing this sql command on each refresh. I would expect to see that command when I first show the module, but not again until the 60 seconds was up.

I am using DNN 4.4.0 and I'm logged out of the system so I should be treated like an anonymous user.

When I do this same test on DNN 3.2.2 it behaves like I would expect, only running that command once every 60 seconds.

Could this be a bug of DNN 4.4.0?

Hi Philip,

I was logged out when I completed the test. Here's a way to duplicate what I did. Perhaps there is another setting that is affecting the cache.

Using the DNN 4.4.0 install package, I created a brand new DNN install and logged in as host. I deleted all of the modules from the home page, except for the 'Welcome to DotNetNuke' module. I changed the cache setting in that module to 60 seconds and logged off. I started a trace against the database and repeatedly refreshed the page using F5. On each refresh, the dbo.DNN_GetHtmlText proc is run.

Under Performance Settings I have the following:

Page State Persistence = Memory
Module Caching Method = Disk
Performance Setting = Moderate Caching
Authenticated Cacheability = ServerAndNoCache
Compression Setting = GZip Compression
Compression Level (Deflate) = None
Use Whitespace Filter = True (checked)

I've tried messing with Light and Heavy Caching but the same thing happens. Has anyone been able to duplicate my findings?