Before you can
determine how many servers you need in your farm and on which servers to
install applications, decide which applications you want to deliver and how you
want to deliver them.
factors when defining your farm’s hardware and operating system configuration:
- Can I run the applications?
Citrix recommends testing non-Vista-compliant applications before you publish
them on your farm. Some non-Vista-compliant applications run using the
Application Compatibility feature.
- How many users do I
anticipate will want to connect to each application during peak and off-peak
hours? Do I need to allocate servers for load balancing?
- Will users be accessing
certain applications frequently? Do I want to publish all of these applications
on the same server to facilitate session sharing and reduce the number of
connections to a server? If you want to use session sharing, you might also
want users to run applications in seamless windows. .
- Will my organization need to
provide proof of regulatory compliance for certain applications? Will any
applications undergo a security audit? If you intend to use SmartAuditor to
record sessions on these servers, install the SmartAuditor agent on these
servers. In addition, make sure the servers have sufficient system resources to
ensure adequate performance.
- Will any of my applications
be graphically intensive? If so, consider using the XenApp SpeedScreen, Memory
Utilization Management, or CPU Utilization Management features as well as more
robust hardware for sessions hosted on these servers.
Assessing Applications for XenApp Compatibility
Ensure applications are compatible with the server operating system
and are multiuser compatible. Application compatibility drives the application
delivery method (for example, accessed from the server, streamed to server, or
streamed to client desktops).
Evaluate whether or not applications are compatible with multiuser
environments and, if so, the application server’s scalability. Before testing
applications for compatibility, investigate how the application works with
Remote Desktop Services or XenApp. Remote Desktop Services-compliant and
Windows Logo certified applications experience few, if any, issues compared
with noncompliant applications.
Initial application compatibility testing typically involves
publishing the application so that is installed and hosted on a server in a
test farm and having multiple test users connect to it. Applications that
function correctly should be tested for conflicts with other applications you
want to install on the server and, then, scalability.
Applications that do not function correctly might not have been
designed for multiuser, multiapplication environments. Applications not
designed for these environments can conflict with other applications or have
scalability or performance issues. Registry settings, attempts to share files
or DLLs, requirements for the exclusive use of files or DLLs, or other
functionality within an application can make it incompatible. You can resolve
some application issues through streaming, using features like Virtual IP, or
siloing the application.
After testing, if these solutions do not work, you might need to find
and fix the root cause of the problem. To identify root applications issues,
consider using tools like the Microsoft Application Compatibility Toolkit (ACT)
or Microsoft’s Windows Sysinternals. Examples of common issues include:
- .INI files that contain
hard-coded file path names, database connection settings, and read/write file
locking configurations that need to be reconfigured to prevent file conflicts.
- Custom applications
developed with hard-coded paths in the registry.
- Applications that use the
computer name or IP address for identification purposes. Because a server can
run multiple instances of the application, all instances could use the same IP
address or computer name, which can cause the application to fail.
When you find any of these hard-coded settings or other conflicts,
document the setting in your farm design document. After you find resolutions
to these issues, design your farm and test your design by creating a pilot test