Hi All

If anyone can provide any assistance with this it would be much appreciated. I have an Umbraco site that is load balanced in a 'Sorry state' i.e. web server 1 serves the site on the domain while active, then should that site fail an exact replica of the site on web server 2 kicks in a takes over until the first site is fix/starts responding.

So far I had had no problems with the installation. I have both site communicating via distributed calls, and I have Microsoft Sync Toy install on the servers to manage the copying of all other files from one server to the next.

However one night this weekend the second site went down with the following errors occuring repeatedly in the event log:

- Unable to find assembly 'Lucene.Net, Version=2.9.2.2, Culture=neutral, PublicKeyToken=null'
- Lucene.Net.Index.MergePolicy+MergeException
- Faulting application name: w3wp.exe, version: 7.5.7600.16385, time stamp: 0x4a5bd0eb
Faulting module name: KERNELBASE.dll, version: 6.1.7600.16385, time stamp: 0x4a5bdfe0
Exception code: 0xe0434352
Fault offset: 0x000000000000aa7d
Faulting process id: 0x12cc
Faulting application start time: 0x01cc1d11465b233a
Faulting application path: c:\windows\system32\inetsrv\w3wp.exe
Faulting module path: C:\Windows\system32\KERNELBASE.dll
Report Id: 86e10eb0-8904-11e0-b686-0050569b0018

The only way to get the site back up and running was to copy the code from the working server back to the broken server.

After checking the Umbraco logs the last event was as follows:

[UmbracoExamine] Error optimizing Lucene index,background merge hit exception: _c20:c2910 _c2v:c25 _c2w:c1 _c2x:c1 _c2y:c1 _c2z:c1 into _c30 [optimize] [mergeDocStores], IndexSet: InternalIndexSet

Can anyone shed any light on what may have happened, and how this would have caused the site to crash so horrendously with any user intervention?

Cheers

Ben