• Learning to Add a New Citrix XenApp Server to a XenApp Farm

    Eventually every Citrix Administrator needs to add an additional server or servers to their farm.  Adding additional servers to the farm, installing applications to them and then adding the new servers to the published applications allows XenApp to provide automatic load balancing of users of those applications across servers.  XenApp uses the concept of Least Busy Server to determine which server will launch the application requested by the user.

    There are two pieces of information you need before you can add an additional server to your Farm:

    1. Database type used for the data store
    2. Server hosting the database

    To find the information on the database and data store will require the use of regedit on a server already in the farm.

    Important This section, method, or task contains steps that tell you how to access the registry. However, serious problems might occur if you access the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following to view the article in the Microsoft Knowledge Base:

    How to back up and restore the registry in Windows

    DATA STORE USING MICROSOFT ACCESS

    Start regedit: Start -> Run type regedit and then click OK.

    Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\IMA.

    The value for DatabaseDriver tells you the type of database being used, ImaAccess.dll is Access.

    DataSourceName shows the location of the DSN file you need to check to find the name of the server hosting the database.

    Looking at the MF20.dsn from the server using Access:

    Shows the Driver as Microsoft Access and the file is located on that server in C:\Program Files\Citrix\Independent Management Architecture.

    You now have the two pieces of information necessary to add a new server to the Farm.

    To see the entire XenApp 5 for Server 2003 installation process, please see this article:  Learning the Basics of XenApp 5 Part 4 of 7.  This article will only show the steps where a new server is added to an existing farm.

    The Farm being used in this article was created for the series Learning the Basics of XenApp 5.  For that series, the Farm was named Learning and two applications were published: Notepad and Paint.  There is only one server in the Farm, CitrixONE, using Access for the data store.  For this article, the server being added is named CitrixTWO.

    On the Create or Join a Server Farm dialog, select Join an existing farm.

    On the Join a Server Farm dialog, enter the name of the server, CitrixONE, that hosts the Access data store.  Accept the default port 2512.

    Note:  Citrix calls this Indirect Connection mode to the data store.  This server is using another server to connect to the data store.  Direct Connection mode is made using the option Connect directly to the database using ODBC.  The difference?  If CitrixONE goes offline, then CitrixTWO no longer has a connection to the data store and farm functionality is severely crippled.  Direct Connection mode does not rely on any other XenApp server for access to the data store.

    Enter the credentials to access the Access database.

    If the wrong credentials are entered, you get a warning message.  Click OK and the entire data store selection process starts over.

    Accept the default Use the global farm settings for the license server.

    DATA STORE USING MICROSOFT SQL SERVER

    Start regedit: Start -> Run -> regedit and then click OK.

    Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\IMA.

    The value for DatabaseDriver tells you the type of database being used, ImaSql.dll is Microsoft SQL Server.

    DataSourceName shows the location of the DSN file you need to check to find the name of the server hosting the database.

    Looking at the MF20.dsn from the server using SQL Server:

    This shows:

    • The driver as SQL Server
    • UID (User ID) used to log into the SQL Server and database is Administrator
    • The server this MF20.dsn came from (WSID) is CITRIXPS.
    • The SQL Server hosting the data store is CitrixSQL
    • The DSN description is Citrix DS

    To see the entire XenApp 5 for Server 2003 installation process, please see this article:  Learning the Basics of XenApp 5 Part 4 of 7.  This article will only show the steps where a new server is added to an existing farm.

    The Farm being used in this article was created for the series Learning the Basics of XenApp 5.  For that series, the Farm was named Learning and two applications were published: Notepad and Paint.  There is only one server in the Farm, CitrixONE, using Access for the data store.  For this article, the server being added is named CitrixTWO.

    On the Create or Join a Server Farm dialog, select Join an existing farm.

    Click Connect directly to the database using ODBC and click Next.

    Enter a description and either type in the name of the SQL Server or click the drop down and select the SQL Server.  Click Next.

    Click Next.

    Click Next.

    Click Finish.

    Click the Test Data Source… button.

    Click OK.

    Click OK.

    Enter the user name and password to access the SQL Database.

    If the wrong credentials are entered, you get a warning message.  Click OK and the entire SQL Server selection process starts over.

    Accept the default Use the global farm settings for the license server.

    XENAPP 5 INSTALL IS COMPLETED

    Looking at the IMA registry key from CitrixTWO:

    Because this is an Indirect Connection, there is nothing in either the DatabaseDriver or DataSourceName registry keys.  There are two new registry keys: PSSERVER and PSSERVERPORT.  The presence of these two registry keys is how to tell if a XenApp server is using a Direct or, in this case, Indirect Connection to the data store.  PSSERVER holds the name of the XenApp server hosting the data store.

    When the XenApp install completes, restart the server, login to Windows and then apply all the same XenApp updates that are on the original XenApp server.  Failure to have the new XenApp server at the same update level as the original will cause version mismatch errors in the Access Management Console (AMC) on the new server.  For the Learning series, Hotfix Rollup Pack #3 was the most current XenApp update.  After all the updates are applied, restart the server, login to Windows and start the AMC on the new server.

    The Configure and run discovery wizard starts.  Since the Web Interface is not installed on the new server, it is deselected.

    To administer both servers from this AMC, click the Add Local Computer button.

    Then click the Add button ..

    .

    and add the original server.

    With both servers in the list of servers to administer, click Next.

    Click Next on the Preview Discovery screen.

    Click Finish.

    Note:  If you are running in a Windows Workgroup environment, you may see “access denied error 0x80041003” as an alert in the AMC.  To resolve this error, add the account used to install XenApp 5 as a Full Farm Administrator.

    The list of published applications and servers can now be seen.

    Right-click the new server, CitrixTWO in this case, select Properties and then License Server.  The new server is using the Farm settings for License Server.

    The next steps to be taken are to:

    • Install applications to the new XenApp server in the same location with the same options as the existing XenApp server
    • Add the new server to the existing published applications
    • Publish any applications that exist only on this XenApp server

    You have learned to add a server to a Farm, determine the type of database used for the data store and verify that your new server is using Farm settings.

    If there is any other aspect of adding a XenApp server to a farm you would like to see covered, send an e-mail to webster@carlwebster.com.

    If you have screen shots for Oracle or DB2 I could use, send them to me and I will make sure you receive credit in the article.

    Thanks

    Webster

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    About Carl Webster

    Webster is a Sr. Solutions Architect for Choice Solutions, LLC and specializes in Citrix, Active Directory and Technical Documentation. Webster has been working with Citrix products for many years starting with Multi-User OS/2 in 1990.

    View all posts by Carl Webster

    2 Responses to “Learning to Add a New Citrix XenApp Server to a XenApp Farm”

    1. Saranya Says:

      Thanks for the sharing, i had a one doubt dont think it is bad i’m a beginner in citrix, If i add a server to the existing farm mean that servar should have the citrix xenapp or not?

      Reply

      • Carl Webster Says:

        Yes, you must install XenApp. During the install, it will ask if you want to Join a Farm or Create a Farm. Select Join, answer the questions and you are on your way.

        Reply

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