Problem: You are not able to connect to your SSAS instance. You got the error message below:

Cannot connect to ServerName\InstanceName.
A connection cannot be made. Ensure that the server is running. (Microsoft.AnalysisServices.AdomdClient)
Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. (System)
An existing connection was forcibly closed by the remote host (System)

This issue occurs with SSAS 2005 or 2008 on Windows 2003 SP2 or Windows 2008.

Background: You have defined a DNS alias for your Analysis Services instance.


Work done:
In SQL Server Management Studio, the connection works fine when :
 - connecting to this SSAS instance remotely with DNSalias\Instance or machineName\InstanceName.
 - connecting to this SSAS instance by replacing DSNAlias by local

The connection doesn't work only in local when server name is DSNAlias\InstanceName

Cause: A loopback check security feature that is designed to help prevent reflection attacks on your computer. Therefore, authentication fails if the FQDN or the custom host header that you use does not match the local computer name.


Workaround: Execute your command remotely or in local with server name like .\instanceName.

There is another  workaround extracts from the article kb http://support.microsoft.com/kb/983444 . The method is to disable the loopback check by setting the DisableLoopbackCheck registry entry. But it's not recommanded. This workaround may make a computer or a network more vulnerable to attack by malicious users or by malicious software such as viruses. Use this workaround at your own risk.

 

See also : Use a DNS alias for SSAS 2005/2008 instance

Michel Degremont | Microsoft Premier Field Engineer - SQL Server Core Engineer |