Browser loads old version of css/masterpage/page layout

Question

We have a few different environments for dev/test/uat and prod, in the prod environment we have an issue with cached files that never get updated. I have compared the site collection settings for cache between the environments and they are all the same. I have compared the web app settings in web.config and they are the same.

In prod, if I delete a file in a library, empty recycle bin, IIS reset, clear browser cache and all I can still browse to it by pasting the URL, but if I go to the library it is gone (and this even after a few weeks).If I add new files it's fine but if I update a style sheet in the style library and download it (send to ->download a copy) I can see the changes but if I click on it to open it in the browser then it's still the old one.

We're using blob cache storage, could this cause an issue like this? I have never really experienced anything like this before.

Any ideas where to start looking?

Edit: I have tried with adding a random query string after images etc. but still get the old version.

Answer 1

Blob cache refreshes on a timed basis only and causes what you are seeing.

However you can clear it via powershell and I think central admin, but here is the powershell:

$webApp = Get-SPWebApplication "<WebApplicationURL>"
[Microsoft.SharePoint.Publishing.PublishingCache]::FlushBlobCache($webApp)

The setting for the time is here in the web config.

" path="\.(gif|jpg|png|css|js|swf|flv)$" maxSize="10" enabled="true" max-age="36000" />