Umbraco cache problems

Question

I am having a problem with the umbraco cms. We are using umbraco 4.6.2 with .net usercontrols. Everything was running fine up until a couple of weeks ago when the client started complaining about updated content not displaying on the front end.

After some investigation I was able to determine that just before this started happening that one of the users experience an error stating that a file in App_Data/ExamineIndexes could not be updated as was in use by another process/locked.

A college suggested that I stop site and delete all files from App_Data/ExamineIndexes folder. I did this and the site ran fine again for a couple of days then same thing happened and I did fix again. This was a daily occurrence for a week and then one day the fix did not work and I was forced to start pulling data directly from umbraco database rather than using the standard umbraco built in methods. This fixed my content caching on existing pages but now when I create new pages the umbraco.config file is not being updated and as a result no new pages are being created.

I've already tried republishing entire site and that does not work. Permissions to the App_Data/umbraco.config are correct.

Has anybody experienced something similar? I would also love to know if somebody could give me a reason why file locked in the first place.

TLDR; Umbraco caching broke and have been unable to get it running again any help will be deeply appreciated.

Answer 1

Check that you Application Pool has Maximum Worker Processes set to 1. Umbraco does some in memory caching before it dumps it out to the XML cache. If your back office is running across multiple processes it gets very confused which is exhibited by showing different versions of pages when you refresh your page, similar to a load balanced web farm with servers that aren't synchronized properly.