Include specific folder content in BlobCache SharePoint

It is quite possible that you instruct blob cache framework to include only specific SP document Libraries . ( I have mentioned it as document libraries , as you must be aware it does not work well with custom folders created using designer etc)

Suppose I have few heavy .jpeg  and .dhx  in a spdocumentLibrary called  HeavyContent .

I want to cache all .pdf , .doc ,.docx ,.flv,.f4v ,.swf  in my web application , but  .jpeg and .dhx   are the one only from spdoc lib "HeavyContent"

Search for a tag similar to below mentioned  in web.config and edit the path parameter.  :

<BlobCache location="C:\myBlob\Public" path="(\.(doc|docx|pdf|swf|flv|f4v)$|HeavyContent.*\.(dhx|jpeg)$)" maxSize="10" max-age="86400" enabled="true" />

This will mark items as specified by path parameter regex  for 24 hrs , to be cached.

\.(doc|docx|pdf|swf|flv|f4v)$    <---->  everything which ends with extension mentioned

|                                            <---->   or

HeavyContent.*\.(dhx|jpeg)$ <----> content inside HeavyContent ending with dhx or jpeg



Disclaimer : I am not sure how performance will be affected by making path parameter complex.

Mime Types with BlobCache

Now suppose your IIS does not support some mime types like dhx and f4v.  You have two options :

Option 1 : add mime type at server level in IIS.

Option 2 : use    browserFileHandling = "Nosniff"  in the webconfig section discussed above.  [ Ref : http://blogs.msdn.com/b/ie/archive/2008/09/02/ie8-security-part-vi-beta-2-update.aspx ]

How to  Flushing the BLOB cache

1. IISRESET [Recommended : Increase the startup and shutdown time limits on the web application to accommodate the extra time it takes to initialize or serialize the cache index for very large BLOB caches]


2. Powershell :

Write-Host -ForegroundColor White ” – Enabling SP PowerShell cmdlets…”
If ((Get-PsSnapin |?{$_.Name -eq “Microsoft.SharePoint.PowerShell”})-eq $null)
{
$PSSnapin = Add-PsSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue | Out-Null
}

$webAppall = Get-SPWebApplication
foreach ($_.URL in $webAppall) {
$webApp = Get-SPWebApplication $_.URL
[Microsoft.SharePoint.Publishing.PublishingCache]::FlushBlobCache($webApp)
Write-Host “Flushed the BLOB cache for:” $_.URL
}

3. change enable to false in web.config , change location parameter , set enable to true

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