Consideration before XenApp6 installation

Unattended Installation and Configuration

Unattended installation can be performed using the following files:

• XENAPPSETUPCONSOLE.EXE
• XENAPPCONFIGCONSOLE.EXE

Hardware Requirements

Hardware requirements include:

• 64-bit CPU
• 512MB RAM (minimum)
• 32GB disk space (minimum)
• 6MB to 120MB for Web Interface plus 3.5MB for each site

Software Requirements

XenApp must be installed on a Windows Server 2008 R2 operating system (64-bit)

XenApp components such as the Delivery Services Console and Web Interface can be installed on additional operating systems

XenApp Configuration Options

During XenApp configuration, administrators select options for XenApp components and features

Which Farm or Zones Will Be Used in the  Environment?

A farm:

• Can be managed as a single entity
• Use a single data store database
• Can balance load among server in the farm Zones:
• Are a logical grouping of servers within a farm
• Are typically based on geographic location

Which License Server Will Be Used for the Server Farm?

A License Server:

• Can be installed before, during or after the XenApp installation
• Can be installed on a dedicated server or a server that provides additional functionality

Which Database Engine Will Be Used for the Data Store Database?

The following database software can be used for the XenApp data store:

• Microsoft SQL Server Express 2005
• Microsoft SQL Server Express 2008
• Microsoft SQL Server 2005
• Microsoft SQL Server 2008
• Oracle 11g R2

Will Shadowing Be Enabled?

Shadowing allows authorized users to view and interact with user sessions

• The default shadowing sessions are recommended for most farms
• If shadowing is prohibited during the XenApp installation, it cannot be enabled without reinstalling XenApp

On Which Port Will the Citrix XML Service Run?

The Citrix XML Service:

Communicates the least busy server and names of published resources

• Uses port 80, by default
• Can share port 80 with IIS
• Can be set to use a port other than port 80

When Will Users Be Added to the Local Remote Desktop Users Group?

Users can be added before or after XenApp installation.

Options include:

• Add the authenticated users
• Add the list of users from the Users group
• Add anonymous users

Which Pass-through Client Will Be Used in the Environment?

The pass-through client:

• Gives users of older, less feature-rich clients access to the features of the Citrix online plug-in
• Allows users to access their published applications through a XenApp Services site

Will Pass-through Authentication Be Used in the Environment?

Pass-through authentication:

• Authenticates a user to XenApp using the credentials used to log on to Windows
• Can be enabled during installation
• Requires the plug-in to be reinstalled on a server, if passthrough authentication is enabled after the XenApp installation

Will Information in the Data Store and Configuration Logging Databases Be Protected with IMA Encryption?

IMA encryption:

• Can encrypt the credentials of the data store and configuration logging databases
• Must be enabled on all XenApp servers if it will be used
• Can be enabled using the CTXKEYTOOL command 

          Eg:   ctxkeytool [generate | load | newkey | backup] filepath

                  ctxkeytool [enable | disable | query]

New Features in XenApp 6.5

Application streaming

The steaming client has been enhanced to allow VHD’s to be mounted directly as the RadeCache. This is specifically for the pooled desktop scenario where you don’t want users generating lots of write IOPS to your difference disk by launching streaming applications that then create the radecache (i.e. write traffic), which in turn gets redirected into the difference disk thus generating write IOPS.

Mounting the VHD directly into the filesystem (supported natively by the OS in Windows 7) means the RadeCache is “pre-populated” and thus makes no changes to the system image on first launch, generating no write IOPS to the difference disk, improving application launch time, and reducing load on the storage.

The VHD’s can be created at profiling time by a new version of the Streaming Profiler.

Load evaluators

Citrix have removed the ability to assign load evaluators directly to servers (and also the corresponding Set-XAServerLoadEvaluator Power Shell command). Load evaluators can now only be assigned to servers via a Worker Groups or OUs and applied by XenApp/AD group policy.

This has the advantage that newly provisions servers can automatically be assigned a non-default load evaluator based on it’s OU membership.

The biggest knock-on effect of this is that load evaluator changes will now be subject to the AD policy refresh period, as per all other XenApp policies, whereas previously they were picked up on the next LHC/datastore sync.

Multi-stream ICA

The single TCP Stream that used to run over port 1494 (or 2598 with session reliability) can now be split into four separate TCP streams if required. These can then be assigned different network-level QoS policies to prioritise certain kinds of ICA traffic over others. There is also a UDP audio stream for XenDesktop.

 

Desktop Director for XenApp

The Desktop Director web-based console shipped with XenDesktop has now been enhanced and includes XenApp sessions, and HDX monitor functionality.

Session pre-launch

Session pre-launch starts up a pre-defined application on the server at a specific event (either the user has logged into the client OS, or at a scheduled time). The user is not connected to their session until they actually launch the application via its usual shortcut, but they then only have to wait for a session reconnection (a few seconds) rather than a complete login (upto several minutes depending on your login script and profile size)

Things to bear in mind:

• It’s the client that issues the pre-launch, so you need the new v13 client to support this
• A CCU license is consumed as soon as the pre-launch session is active, so you might start consuming more CCU licenses
• Running many prelaunch sessions may require more XenApp server resources to cover sessions pre-launched but not yet in use. Remember the application is still running in a pre-launch session – just that the user is not yet connected to it.

Session linger

Normally when you close the last application in your session, you will be logged off the server and your session will close. Session linger allows that session to remain for a period determined by policy. The advantage of this is that if you then decide to launch the same, or another application, it will launch almost instantly, as it won’t have to perform all the login actions (logon scripts, loading your profile etc)

The disadvantages are that there are server resources being consumed by users who aren’t using any applications, and sessions that are lingering are still consuming a CCU license.

Data store configuration by policy

In XenApp 6, support was added to allow XenApp servers to be provisioned, however there were a few
leftovers of configuration that still had be to “baked into the image”. These were the Zone that the server was to be added, and the data store configuration.

Both these items can now be configured into an AD Group Policy Object (GPO) meaning servers will inherit their data store configuration and zone information based on the parent OU the server is added to. Note these policies are the only ones that can’t be stored in IMA as the server has no IMA connection at the time these policies are applied (i.e. server farm joining)

New “session-only” and “controller” roles

New Session-only role : no XML service, sync’s fewer data store tables to reduce data store replication when adding/removing servers from the farm

Controller role: Full XenApp functionality (akin to a XenApp 6.0 server). Can be used for Zone Data Collectors and XML Gateways.

These changes mainly impact larger farms only where adding/removing servers cause a large amount of datastore replication traffic, putting stress on the datastore and ZDCs.

Biggest impact to farm administrators will be that you won’t be able to run the AppCenter console (formerly Discovery Services Console) on any server in your farm and choose “localhost” in the discovery – you will have to point the console at a Controller server.

Power & Capacity Management

• Can now query and control VM power status using Hypervisors API
• Support for Hyper-V and ESX/vSphere added
• Can now use the new Logon control feature to drain users

Probably by the month of September Xenapp 6.5 will release.