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 |

You would like to configure a DNS alias (CName) for each server to  redirect transparently clients for high availability.

There is no indication against to use a DNS alias, you can use CNAME to connect to SSAS 2005 or greater. However there are some considerations to take into account.

1. Be carefully on cluster system

2. Be sure that you can “reverse lookup” the CNAME / Alias. SSAS has to reverse lookup the hostname during connection 

3.  Changing the DNS Alias: DNS caching might cause some delay
- Client side cache: It can be cleared with ipconfig /flushdns
- Server Side cache : Depends on the structure, by multilevel structure multiple caches might exist Clearcache possible with dnscmd or GUI (there are settings for the cache lifetime but it is not recommended to change them (it might increase the traffic on the DNS server))

4. Cannot connect locally to your SSAS instance using DNS alias

5.  As the alias uses only server name you cannot configure the protocol , the name of the instance or the port.

6.  At kerberos level you can have false SPN. The SPN needs to be re-registered on the alias name too.

7.  At TCP level you can have errors

8.  DNS will no provide an port information to clients.  If Default instance is listening on a non-default port (SQL Browser cannot redirect) , then port has to be defined in the connection string.

You can create a DNS alias following this article kb: How to set up application names in SQL Server 2000 Analysis Services

Connect bug: Create and alias to a (named) instance of Analysis Services 2005/2008

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

You will find below a summary of important points to know to use the mount points with SQL Server.

SQLServer andSSASsupportsmount points in cluster if and onlyif atleast one letternamed asthe primary driveby instance.Then youcan add yourmount points.

You must also meet the following prerequisites:
1. You can not put the files directly to the root mount point. It is imperative to create the root of each mount point, a directory, then place the files in that directory.
2. As part of a cluster for each mount point, you must create a cluster resource. Then add a dependency to indicate that SQL Server will not start if all dependencies and disk mounting points are not all online.

In addition, references to KB articles:

1. FIX: You are prompted to format the volume when a formatted volume is mounted on a NTFS folder that is located on a computer that is running Windows Server 2008 or Windows Vista (http://support.microsoft.com/kb/971254/ )

2. It is recommended not to put files to the root of the mount point for support by Microsoft for support. Solution: create a directory to deposit your files.

E.G. SQL Server 2008 setup fails to install on a Windows Server 2008-based cluster mount point(http://support.microsoft.com/kb/2216461/)
“Note: SQL Server does not support installing to the root of the Volume Mount point because the permissions are not propagated to the Mount Point since Windows does not let you replace permissions on the root of a volume. To prevent problems during new installations and applications of updates to SQL Server, to create a folder on the root of the mount point and install to that folder. At this point, permissions are set correctly. If you previously installed to a root directory, we highly recommended that you create a folder, validate the current database integrity by using the DBCC CHECKB process, and then move the database to the folder.” To work around this problem, simply create the root of each mount point, directory, then move the files in that directory.

3. Cluster : Dependencies and mounts point : http://support.microsoft.com/kb/819546/
“The SQL Server 2005 (and later versions) resource depends on the SQL network name resource and the physical disk resources that hold its data. When mount points are being used together with the physical disks, each mount point must appear as a cluster resource. Additionally, each mount point must also be added as a SQL Server dependency. If only the root physical disks dependency is added and the mount points are not added, database corruption will occur on failover. Database corruption may also occur when SQL Server is restarted without failing over.”

4. Cluster : SQL Server support for mounted volumes(SQL 2000,2005 and 2008) : 
"Because of the number of available drive letters, the number of the virtual instances on a cluster is limited to 25. SQL Server 2005 and later versions have the same limitation. SQL Server supports use of mount points hosted only by drives that have drive letters that are not hosted by other mount points."  (http://support.microsoft.com/kb/819546)

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

I will try to illustrate how to get various information about Analysis Services by using powershell.

You could find below the first script to make the first connection:

$serverName = "serverName\SQL2008_InstanceName"

# Load the AMO assembly in Powershell
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.AnalysisServices")

# Create a server object :
$serverAS = New-Object Microsoft.AnalysisServices.Server

# Connect to your Analysis Services server
$serverAS.connect($serverName)

# Select the information
$serverAS | SELECT  Name,Edition,Version

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

You could find below a sample a script powershell to see which property is no default value of Analysis Services:

$serverName = "serverName\SQL2008_InstanceName"

# Load the AMO assembly in Powershell
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.AnalysisServices")

# Create a server object
$serverAS = New-Object Microsoft.AnalysisServices.Server

# Connect to your Analysis Services server
$serverAS.connect($serverName)

# Creation of my dataset to store my result
$myDS = new-object System.Data.DataSet
$myDS.Tables.Add("myDS")
$myDS.Tables["myDS"].Columns.Add("name",[string])| out-null
$myDS.Tables["myDS"].Columns.Add("value",[string])| out-null
$myDS.Tables["myDS"].Columns.Add("defaultvalue",[string])| out-null

# Browsing all properties to see which one has been changed  
foreach($b in $serverAS.ServerProperties | SELECT name,value,defaultvalue )
{
    # Check if the current value is different from the default value
    if ($b.value -ne $b.defaultvalue)
    {       
   
        # Add a new row to my Data Set
        $dr = $myDS.Tables["myDS"].NewRow()
       
        # Fill the cells
        $dr["name"] =  $b.name;
        $dr["value"] = $b.value.ToString();
        $dr["defaultvalue"] = $b.defaultvalue;
       
        $myDS.Tables["myDS"].Rows.Add($dr)

    }

}

# Query the result
$myDS.Tables["myDS"] | SELECT  name,value,defaultvalue;

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

Sometime , Analysis services engine terminates unexpectedly with an internal error when unexpected exception occurred. In this case, you could find in the log directory various mini memory dump.

It is recommended to contact Microsoft Support to help on the analysis of the dump to identify the root cause of the problem

$serverName = "serverName"
$instanceNameOLAP = 'mySSAS_InstanceName'
 
# Get the internal OLAP instance Name 
$InternalInstanceName=(get-itemproperty -path "HKLM:\SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\OLAP").$instanceNameOLAP

# Get the registry path where dumpDir is located 
$keyName="HKLM:\SOFTWARE\Microsoft\Microsoft SQL Server\"+$InternalInstanceName+"\CPE"

# Get the value of ErrorDumpDir key
$serverLogFolder=$(Get-ItemProperty $keyName).ErrorDumpDir

# Lists the objects stored in this folder where the extension is .mdmp.
$dump = dir $serverLogFolder | ?{$_.name -match “^*.mdmp$”}

foreach ($b in $dump | SELECT LastWriteTime,Name)
{
    write-host 'Found memory dump inside '$serverLogFolder
    break;
}

$dump | SELECT LastWriteTime,Name, Length

Script updated  9th April 2012.

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

Previously, SSAS was listening on all IP addresses of the cluster group using the default port (2383). Any alternate port configuration is ignored until version 2005 and 2008/R2. It’s not the same behavior with a standalone instance. 

But since Analysis Services 2012, we are able to change the default  port in cluster by editing the properties or msmdsrv.ini file.

Don't forget to configure your firewall to allow incoming requests on TCP port 2383. See also others port: 2382, 80,440 (Configure the Windows Firewall to Allow Analysis Services Access)

Test case:

- In my test below, I run the command  tasklist /svc | findstr msmdsrv to get the processID of my instance SSAS 2012.

- Then, I run netstat -ano | findstr <myProcessID> to check if my instance is listening on my new configured port 5555.

- As you can see, it works :-)

Regarding the limitation of 2005/2008:
- http://connect.microsoft.com/SQLServer/feedback/details/377639/2008-rtm-ssas-named-analysis-services-instance-port-doesnt-adjust-to-the-configured-port-after-a-failover
- http://support.microsoft.com/kb/2466860
- http://blogs.msdn.com/b/karang/archive/2009/09/05/sql-server-analysis-services-port-sql-2005-2008.aspx

 IMPORTANT (9 November,2012) :  Although you can connect to instance like "virtualName:port" ,  my colleague from Support Team confirm me, that we are not allow to change de port 2383 on clustered instance.

Port configuration for an Analysis Services cluster : On computers that have multiple network cards, Analysis Services listens on all IP addresses using the port you specify. On a clustered instance, Analysis Services will listen on all IP addresses of the cluster group, but only on TCP port 2383. You cannot specify an alternate fixed port for a clustered instance. (http://msdn.microsoft.com/en-us/library/ms174937.aspx#bkmk_cluster

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

How add Analysis Services to a clustered SQL Server instance ?

It's not supported to Add or Remove features for Clustered instances

SQL Server setup 2012 does not support adding features to an existing failover cluster instance. By using the wizard, you will get the following error message:
-  Instance name '<Instance Name>' is already in use. To continue, specify a unique instance name.
- The SQL Server failover cluster instance name '<virtual name>' already exists as a clustered resource.  Specify a different failover cluster instance name.

Analysis Services cannot be added to an existing instance of SQL Server. To share a resource group with an instance of SQL Server, you must choose to install Analysis Services during the initial installation of SQL Server. On the same note removing features from a clustered instance is also not supported.

Reference regarding old version: You cannot add or remove features to a SQL Server 2008 or SQL Server 2008 R2 failover cluster

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

Problem description : The PowerShell command below uses to run every 5 minutes. But since 2 days, I got the error message below :  Invoke-Sqlcmd : The 32-bit OLE DB provider "MSOLAP" cannot be loaded in-process on a 64-bit SQL Server.

 (Invoke-Sqlcmd -ServerInstance $R -Database SSAS_Monitor -Query "INSERT INTO dbo.SSAS_DISCOVER_SESSIONS SELECT  '$I', getdate(), * FROM OpenRowset('MSOLAP', 'Data Source=$I;' ,'SELECT * FROM `$system`.DISCOVER_sessions WHERE SESSION_USER_NAME <> ''$proxy''')")

Work done :
-  I had a look to windows event system and application but I didn’t see any error about that.
-  I didn’t see any reboot or new installation of any Hotfix or whatever.
-  I can see that provider for 32bit and 64bit are installed for MOLAP.5 (2012 RTM for the both)
-  I can see that provider for 32Bit only was installed for MOLAP.4 (2008 R2 RTM)
-  Process Monitor didn’t give me any clue.
-  I restarted the server just in case, but theissue was still there.

Workaround : It looks like my query is using now MOLAP.4 instead of MOLAP.5 (I guess but not sure). As the version for 2008R2 is installed only in
32bit,the script failed with the message The 32-bit OLE DB provider "MSOLAP" cannot be loaded in-process on a 64-bit SQL Server

Step 1 : Unregister the both DLL:

regsvr32 /u "C:\Program Files (x86)\Microsoft Analysis Services\AS OLEDB\110\msolap110.dll"
regsvr32 /u "C:\Program Files\Microsoft Analysis Services\AS OLEDB\110\msolap110.dll"

Step 2 : Register the both DLL, with 32Bit in first position:

regsvr32 "C:\Program Files (x86)\Microsoft Analysis Services\AS OLEDB\110\msolap110.dll"
regsvr32 "C:\Program Files\Microsoft Analysis Services\AS OLEDB\110\msolap110.dll"

Step 3 : Restart SQL Service

After that, everything was working well :-)

Relative links :

- Explanation of Regsvr32 usage and error messages
- How to perform a SQL Server distributed query with OLAP Server

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

Analysis Services is clustered as  a generic service resource on a Windows failover cluster. This applies to 2005, 2008, 2008R2, and 2012.

Since SSAS 2005 version, Analysis Services is fully integrated into clustering Setup (the install of SQL):

        - SSAS 2005 cluster setup is adding the service on all cluster nodes on the same setup
        - SSAS 2008, the setup have to be done node by node Analysis Services is presented to the cluster as generic resource with the type Application Service and doesn’t implement his own explicit IsAlive method. Unlike SQL Server, Analysis Services doesn't have a cluster resource .dll that knows how to do that work like connect to AS and run a simple query to check that it responds.

Possible cause of failure that is detected for an Application Service:

       - The service stopped(ie. crash, or was killed) then the cluster resource would notice
       - A dependency in the group where the generic service is configured failed (a disk fails or goes offline, an IP, virtual name, mount point, SQL server…other dependencies affecting the group)

Note :Application Service will NOT detect a hang situation in SSAS, where all connections are rejected.

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

Problem description: After you moved SSAS databases to a new drive on the same server, you are not able to administrate  Analysis Service. SSAS databases is up and running. When you add a database or user, it appears that users are added successfully, but when going back out of the dialog nothing happened.

Work done: To move you database to a new drive, you followed the step below.
  
   Step 1: With Microsoft SQL Server Management Studio, connect to Analysis Server, then right Click on the server and click on Properties.
   Step 2: Edit the path of you data directory. And replace the old path by the new one.
   Step 3: Stop the SQL Server Analysis Services Service.
   Step 4: Move the Data to the new directory location.
   Step 5: Start the SQL Server Analysis Services Service.
   Step 6: verify that you can browser all database.

Cause: Inside the SSAS log, you can see an  issue relating to something not allowing SSAS to update or access this file

     Message: Service started. (Source: ?\D:\Log\msmdsrv.log, Type: 1, Category: 289, Event ID: 0x41210000)
     Message: The file '\\?\E:\OLAP\Data\master.vmp' could not be deleted.
     Please check the file for permissions. (Source: ?\D:\Log\msmdsrv.log, Type: 3, Category: 289, Event ID: 0xC121001F)

I run Process Monitor and after SSAS restart I saw an access denied on various file and also on master.vmp.

For insformation:  The master.vmp file is the master version map that contains the GUIDS for all of the objects and the version of each object that currently exists on the server. When the server starts, it looks at the master.vmp file and need to update it ( More information with my colleague Karan)

Resolution: You can solve this issue you can give the right "Modify" to SSAS service account to this new data folder.

Others points:

1. A database can be moved in many ways (SSMS Attach/Detach, AMO, XMLA). You could find some various way in the bol (Move an Analysis Services Database)
2. You can only move the file regarding Data, Backup, Log or Temp. However it's not supported to move manually the BIN and Config directory. You must reinstall your instance.

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

Problema:  No son capaces de conectarsea la instancia deSSAS.Ustedtiene elmensaje de error siguiente :

No se puede conectar a InstanceName
No se puede establecer una conexión. Asegúrese de que se está ejecutando el servidor. (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)

Este problema se produce con SSAS 2005/2008 en Windows 2003 SP2/Windows 2008.

Antecedentes:Se ha definidoun alias deDNSpara lainstancia de Analysis Services.

Trabajo realizado: En SQL Server Management Studio, la conexión funciona bien cuando: 
 - conectarse a esta instancia de SSAS de forma remota con DNSalias\Instancia o machineName\InstanceName.
 - conectarse a esta instancia de SSAS mediante la sustitución de DSNAlias ​​por locales

La conexión no funciona sólo en locales cuando el nombre de servidor es DSNAlias\InstanceName

Causa: Una comprobación de bucle invertido característica de seguridad que está diseñado para ayudar a prevenir los ataques de reflexión en el equipo. Por lo tanto, la autenticación falla si el FQDN o el encabezado de host personalizado que utiliza no coincide con el nombre del equipo local.

Solución: Ejecutar el comando de forma remota o en local con el nombre del servidor como .\instanceName.

Hay otra solución extractos del artículo de KB http://support.microsoft.com/kb/983444. El método consiste en deshabilitar la comprobación de bucle invertido mediante el establecimiento de la entrada del Registro DisableLoopbackCheck. Pero no es recomendada. Esta solución temporal puede hacer que un equipo o una red sean más vulnerables a los ataques de usuarios malintencionados o de software malintencionado, como los virus. No recomendamos esta solución, pero proporcionamos la información para que pueda decidir por sí mismo si la implementa. Utilice esta solución temporal bajo su responsabilidad.

Véase también : Usar un alias de DNS para una instancia SSAS 2005/2008

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

Problème : Vous n'arrivez pas à vous connecter à votre instance SSAS. Vous obtenez le message d'erreur suivant :

Ne peut pas se connecter à InstanceName
Une connexion ne peut pas être établie. Vérifiez que le serveur est en cours d'exécution. (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)

Ce problème arrive sur  SSAS 2005/2008 on Windows 2003 SP2 or Windows 2008.

Configuration : Vous avez défini pour cette instance Analysis Services un alias DNS.

Travaux réalisés : Dans SQL Server Management Studio, la connexion  fonctionne correctement  quand :
 - la connexion à cette instance SSAS est distante avec comme nom instance  DNSalias\InstanceName ou  machineName\InstanceName.
 - la connexion à cette instance SSAS est local mais que vous remplacez le nom de l'alias DNS par local

En claire, la connexion ne fonctionne pas uniquement quand vous êtes en local et que vous entrer en nom de serveur l'alias DNS.

Cause : C'est dû à une fonctionnalité de sécurité  de bouclage qui est conçu pour aider à prévenir les attaques par réflexion sur votre ordinateur. Par conséquent, l'authentification échoue si le FQDN ou l'en-tête d'hôte personnalisé que vous utilisez ne correspond pas au nom de l'ordinateur local.

Solution de contournement : Executez vos commandes à distance lorsque vous utilisez un alias DNS ou en local mais en modifiant le nom du serveur par  .\instanceName.

Il existe une autre solution de contournement extraits de l'article http://support.microsoft.com/kb/983444 . La méthode consiste à désactiver le contrôle de bouclage en définissant l'entrée DisableLoopbackCheck dans la base de registre . Mais cette opération n'est pas recommandée. Cette solution de contournement peut rendre un ordinateur ou un réseau plus vulnérable aux attaques d'utilisateurs malintentionnés ou de logiciels malveillants comme les virus. Utilisez cette solution de contournement en toute connaissance de cause.

Voir aussi : Utilisez un alias DNS pour une instance SSAS 2005/2008

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

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 |

Que le gustaría configurar un alias de DNS (CNAME) para cada servidor para redirigir de forma transparente los clientes de alta disponibilidad.

No hay ninguna indicación para utilizar un DNS contra alias CNAME que usted puede usar para conectarse a SSAS 2005 o mayor. Sin embargo hay algunas consideraciones a tener en cuenta.

1. Con cuidado con a cluster sistema

2. Asegúrese de que usted puede "reverse lookup" el CNAME/Alias​​. SSAS tiene que invertir de búsqueda el nombre de host durante la conexión.

3.  Cambiar el alias de DNS: DNS caching puede provocar algún retraso :
- Caché de cliente lado: Se puede borrar con el comando ipconfig / flushdns.
- Caché del lado del servidor: Depende de la estructura, por la estructura de varios niveles multiples caches pueden existir clearcache posible con dnscmd o GUI (hay configuraciones para la vida de cache pero no se recomienda para el cambio (que podría aumentar el tráfico en el servidor DNS)).

4. No se puede conectar a nivel local para la instancia de SSAS con el alias de DNS

5. A medida que el alias sólo utiliza el nombre del servidor no se puede configurar el protocolo, el nombre de la instancia o el puerto.

6. A nivel de kerberos se puede tener SPN falsa. El SPN es necesario volver a registrarse en el nombre del alias también.

7. En el nivel TCP que puede tener errores.

8. DNS no proporcionará una información del puerto a los clientes. Si la Instancia predeterminada escucha en un puerto no predeterminado (SQL Browser no puede redirigir) , entonce el puerto tiene que ser definido en la cadena de conexión.

 Puede crear un alias de DNS siguiente este artículo KB: Cómo configurar los nombres de aplicación de SQL Server 2000 Analysis Services

Connect bug: Create and alias to a (named) instance of Analysis Services 2005/2008

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

Vous souhaitez configurer un alias DNS (CNAME) pour chaque serveur afin rediriger de manière transparente des clients pour  de la haute disponibilité.

Il n'y a pas d'indication contre à l'utilisation d'un alias DNS, vous pouvez utiliser un CNAME pour vous connecter à vos instances  SSAS 2005 ou supérieur. Cependant il y a quelques considération à prendre en compte.

1. Attention dans un environnement en cluster.

2. Soyez sûr que vous pouvez  faire un "reverse lookup"  sur le CNAME/Alias. SSAS doit pouvoir faire une recherche inversé sur le nom d'hôte lors de la connexion

3.  Modification de l'alias DNS: DNS cache peut causer un certain delai
- Cache côté client: il peut être effacé avec ipconfig / flushdns
- Cache côté serveur: dépend de la structure, pour les structures multi-caches multiples il peut exister un ClearCache possible avec dnscmd ou GUI (il ya des paramètres pour la durée de vie du cache, mais il n'est pas recommandé de les changer (il pourrait augmenter le trafic sur le serveur DNS))

4. Impossible de se connecter localement à votre instance SSAS en utilisant l'alias DNS

5. Comme l'alias utilise le nom du serveur que vous ne pouvez pas configurer le protocole, le nom de l'instance ou le port.

6.  Au niveau kerberos vous pouvez avec un SPN faux. Le SPN a besoin d'être enregistré sur le nom de l'alias DNS aussi.

7.  Au niveau TCP vous pouvez avoir des erreurs.

8.  DNS ne fournira pas d'information sur le port à ses clients. Si l'instance par défaut écoute sur un défaut non-port (SQL Browser ne peut pas rediriger), le Port doit être défini dans la chaîne de connexion.

Vous pouvez créer un alias DNS en suivant l'article KB suivant : Comment configurer des noms d'application dans SQL Server 2000 Analysis Services

Connect bug: Create and alias to a (named) instance of Analysis Services 2005/2008

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

You would like to configure a DNS alias (CName) for each server to  redirect transparently clients for high availability.

There is no indication against to use a DNS alias, you can use CNAME to connect to SSAS 2005 or greater. However there are some considerations to take into account.

1. Be carefully on cluster system

2. Be sure that you can “reverse lookup” the CNAME / Alias. SSAS has to reverse lookup the hostname during connection 

3.  Changing the DNS Alias: DNS caching might cause some delay
- Client side cache: It can be cleared with ipconfig /flushdns
- Server Side cache : Depends on the structure, by multilevel structure multiple caches might exist Clearcache possible with dnscmd or GUI (there are settings for the cache lifetime but it is not recommended to change them (it might increase the traffic on the DNS server))

4. Cannot connect locally to your SSAS instance using DNS alias

5.  As the alias uses only server name you cannot configure the protocol , the name of the instance or the port.

6.  At kerberos level you can have false SPN. The SPN needs to be re-registered on the alias name too.

7.  At TCP level you can have errors

8.  DNS will no provide an port information to clients.  If Default instance is listening on a non-default port (SQL Browser cannot redirect) , then port has to be defined in the connection string.

You can create a DNS alias following this article kb: How to set up application names in SQL Server 2000 Analysis Services

Connect bug: Create and alias to a (named) instance of Analysis Services 2005/2008

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