Basic Concepts of Citrix XenApp

Citrix Licensing: A Citrix License Server is a required component for all XenApp deployments. Install the license server on either a shared or standalone server, depending on your farm’s size. After you install the license server, download the appropriate license files and add these to the license server.

Data Store: The data store is the database where servers store farm static information, such as configuration information about published applications, users, printers, and servers. Each server farm has a single data store.

Data Collector: A data collector is a server that hosts an in-memory database that maintains dynamic information about the servers in the zone, such as server loads, session status, published applications, users connected, and license usage. Data collectors receive incremental data updates and queries from servers within the zone. Data collectors relay information to all other data collectors in the farm. By default, the first server in the farm functions as the data collector. By default, the data collector is configured on the first farm server during the Create Farm Setup and all other servers are configured so they have equal rights to become the data collector if the data collector fails. When the zone’s data collector fails, a data collector election occurs and another server takes over the data collector functionality. Farms determine the data collector based on the election preferences set for a server. The data collector is an infrastructure server and applications are not typically published on it.

Zone: A zone is a grouping of XenApp servers that communicate with a common data collector. In large farms with multiple zones, each zone has a server designated as its data collector. Data collectors in farms with more than one zone, function as communication gateways with the other zone data collectors. The data collector maintains all load and session information for the servers in its zone. All farms have at least one zone, even small ones. The fewest number of zones should be implemented, with one being optimal. Multiple zones are necessary only in large farms that span WANs.

Streaming File or Web Server: Applications can be delivered to users by either streaming or hosting the applications on the server. If you are streaming applications, either to client or server, you must install a streaming file server in your environment. When streaming applications, you create profiles of the application and then store the profile on a file or Web server. The profile consists of the manifest file (.profile), which is an XML file that defines the profile, as well as the target CAB files, a hash key file, the icons repository (Icondata.bin), and a scripts folder for pre-launch and post-exit scripts.

Web Interface: The Web Interface is a required component in any environment where users access their applications using either the XenApp plugin or a Web browser. Install the Web Interface on a stand-alone computer; however, where resources are limited, the Web Interface is sometimes collocated with other functions. For instructions, see the Web Interface Administrator’s Guide.

XenApp Web and XenApp Services Sites: XenApp Web and XenApp Services sites (formerly known as Access Platform and Program Neighborhood Agent Services sites, respectively) provide an interface to

the server farm from the client device. When a user authenticates to a XenApp Web or XenApp Services site, either directly or through the XenApp plugin or the Access Gateway, the site:

• Forwards the user’s credentials to the Citrix XML Service
• Receives the set of applications available to that user by means of the XML Service
• Displays the available applications to the user either through a Web page or by placing shortcuts directly on the user’s computer.

Citrix XML Service and the Citrix XML Broker: The Citrix XML Broker functions as an intermediary between the other servers in the farm and the Web Interface. When a user authenticates to the Web Interface, the XML Broker:

• Receives the user’s credentials from the Web Interface and queries the server farm for a list of published applications that the user has permission to access. The XML Broker retrieves this application set from the Independent Management Architecture (IMA) system and returns it to the Web Interface.
• Upon receiving the user’s request to launch an application, the broker locates the servers in the farm that host this application and identifies which of these is the optimal server to service this connection based on several factors. The XML Broker returns the address of this server to the Web Interface.

The XML Broker is a function of the Citrix XML Service. By default, the XML Service is installed on every server during XenApp Setup. However, only the XML Service on the server specified in the Web Interface functions as the broker. (The XML Service on other farm servers is still running but is not used for servicing end-user connections.) In a small farm, the XML Broker is typically designated on a server dedicated to several infrastructure functions. In a large farm, the XML Broker might be configured on one or more dedicated dedicated servers.

The XML Broker is sometimes referred to as a Citrix XML Server or the Citrix XML Service. For clarity, the term XML Broker is used to refer to when the XML Service functions as the intermediary between the Web Interface and the IMA service, regardless of whether it is hosted on a dedicated server or collocated with other infrastructure functions.

Please let me know if the above article was able to provide you with the information you needed.

Changed names with Citrix XenApp 5.0

With Citrix XenApp 5.0 some of the terminologies are changed as were in Citrix Presentation Server. Below is the list of the terminologies that are changed

- Citrix XenApp is the new name for Citrix Presentation Server

- Citrix XenApp Advanced Configuration is the new name for Presentation Server Console.

- Citrix XenApp Pugin for Hosted Application is the new name for plugin for server side virtualization formerly known as Citrix Presentation Client

- Citrix XenApp Agent is the new name for Citrix Program Agent

- Citrix XenApp Provider is the new name for WMI Provider.

- Citrix XenApp Management Pack is the new name for SCOM Management Packs.

- Citrix XenApp Web is the new name for Citrix Web Interface.

- Citrix XenApp Plugin for Streamed Application is the new name for Citrix Streaming Client.

- Branch Optimization is the new name for WAN Optimization.

- Secure Application Access is the new name for Smart Access.

- Easy Call Voice Services is the new name for Easy Call

- Load Testing Service is the new name for Load Testing

- Provisioning Services is the new name for Provisioning Server for Datacenter.

- Profile Management is the new name for Portable Profile Manager

- Workflow Studio Orchestration is the new name for Workflow Studio

Please let me know if the above article was able to provide you with the information you needed.

Introduction to Citrix Presentation Server

Introduction to Citrix Presentation Server

Citrix Presentation server provides application virtualization and application streaming to the users with any device working over any network. It allows delivery of windows application as a service to the users using any network device. Citrix server can be used to:

- Provide tailored secure access control in any access scenario.

- Deliver continuous access across devices, networks and locations.

- Provide scalability and continuous availability for any business scenario.

- Protect information through a multidimensional secure architecture.

- Observer, monitor and measure access infrastructure resources.

Citrix Presentation server enables multiple users to log on and run applications in separate, protected sessions on a single server or multiple servers across a Farm. Server Farm is a group of Citrix servers that you manage as a single entity. Server Farm provides you with a flexible and robust way of deploying applications and content to the users.

Citrix Web Interface

Citrix Web Interface provides the ability to the users to access the published applications using any Web interface.. The Web Interface dynamically creates an HTML page that shows the allowed published application to the users.

You can use Web Interface with Access Gateway or Secure Gateway to transport data securely over the Internet.

The Platinum edition provides Web Interface integration with the Password Manager self-service features (account unlock and self-service password reset). Users can use Password Manager Agent software and register with security questions. When the security questions are registered, the users can reset or unlock their domain password using Web Interface without the intervention of Account Administrator.

Secure Gateway

The Secure Gateway is a secure Internet Gateway device for ICA data travelling into and out of a server farm. You can secure all traffic travelling across the Internet among computers running Citrix Presentation Server and SSL enabled clients

Citrix EdgeSight for Presentation Server

Citrix EdgeSight can be deployed on Presentation Server Platinum edition. It is an end-to-end performance management solution for computers running Citrix Presentation Server. It monitors user sessions and server performance in real time, allowing you to quickly analyze, resolve and proactively prevent problems. You can use Citrix EdgeSight for endpoints for performance management of end user systems.

Resource Manager for Citrix Presentation Server

Resource Manager can be installed on Presentation Server Enterprise Edition. It enables you to collect, display and analyze data about system performance, application use and user activity.

Resource Manager can track and store information about a wide variety of system and network processes and events. If the value of these metrics falls outside normal limits, Resource Manager can warn you by email and pager alerts.

Installation Manager for Citrix Presentation Server

Installation Manager is installed automatically with Citrix Presentation Server Enterprise Edition. Installation Manager lets you install an application package, such as Microsoft Office 2000, from one server to all the servers in a domain or in a server farm. Use Installation Manager whenever you need to deploy applications, files, service packs, or software patches on the servers in your server farm.

You can automate the application installation process, enabling the replication of published applications to computers running Citrix Presentation Server across the enterprise. Automating the process enables you to save time and reduce errors when installing many applications or applications that are frequently updated.

Network Manager for Citrix Presentation Server

Network Manager allows you to remotely control and monitor the status of computers running Citrix Presentation Server Enterprise Edition, using a third party SNMP management console. Network Manager consists of the SNMP Agent for Citrix Presentation Server, installed automatically as part of Citrix Presentation Server Enterprise Edition, and plug-ins for supported SNMP management console applications. Using a third-party SNMP management console, you can terminate processes, send a message to, log off, or disconnect from an active ICA session on a computer running Citrix Presentation Server Enterprise Edition.

Network Manager also includes the Management Information Base (MIB) definition file for Citrix Presentation Server. You can use any SNMP management console application that supports MIB browsing to monitor and control computers running Citrix Presentation Server. The Network Manager plug-ins interact with the SNMP management consoles through API calls provided by the SNMP management consoles. The Network Manager plug-ins automatically:

- Explore and gather information from servers on which the SNMP Agent is enabled.

- Update the gathered data on the network map.

- Log server traps in the event database

Please let me know if the above article was able to provide you with the information you needed.

Citrix Concepts

Citrix Server is available in the three editions, they are
- Standard Edition: It is ideal for small Organization. This edition is used for single server deployment.
- Advanced Edition: It is ideal for small to medium Organization. This edition is used for deploying Citrix servers in a Farm for providing high availability. It adds Load Manager Component.
- Enterprise Edition: It is ideal for large to very large Organization. It provides all the functionality of Advance edition. In addition it adds Installation Manager, Resource Manager, Load Manager, WMI Manager and Network Manager.

Components of Citrix Server

- Installation Manager: It is a toll which helps in deploying packaged installation to Citrix Presentation Server
- Resource Manager: It is a tool to monitor the resources such as event logs and performance monitor logs of Citrix Presentation Server.
- Load Manager: It is a tool used for managing the load of Citrix Server in a Farm.
- Network Manager: It is a tool to connect presentation server to Operations management server.

Citrix Terminology

- Published Application: It is a component for publishing application on Citrix Server. The authenticated users can access the application as if it is being launched from their desktop.
- Published Desktop: it is a tool for publishing entire desktop to the set of users.
- Published Content: It is a tool for publishing the content of the file such a word or an excel file.

Citrix Client

Citrix resources can be accessed by using the below clients
- Program Neighborhood: It provides the flexibility to the end users to the way they connect to the Citrix Server.
- Program Neighborhood Agent: It provides a shortcut which the user can use to access the application published on the Citrix Server.
- Web Client: It provides the accessibility of published applications on the Citrix Server using Web Client
- Java Client: It provides the ability to access published applications on Citrix Server without installing any Citrix Client on user’s desktop.

Citrix Services

Below are the Citrix services that gets installed based on the edition and application you install
- ADF Installer Service
- Citrix CPU Utilization Management / Resource Management service
- Citrix CPU Utilization Management / user-session sync service
- Citrix Licensing Service
- Citrix Licensing WMI service
- Citrix Print Manager service
- Citrix SMA service
- Citrix WMI service
- Citrix XTE Service
- Citrix Virtual memory optimization service
- Client Network
- Diagnostic facility COM server
- Encryption service
- Independent Management Architecture service
- License Management console for Citrix Licensing service
- Metaframe COM server service
- Resource Manager Mail service
- Secure Gateway

Citrix ICA protocol features

- It provides screen updates and mouse / keyboard clicks
- It is optimized for WAN connections (~30-35 kb/sec connection)

Please let me know if the above article was able to provide you with the information you needed.