Citrix Presentation Server 4.0 Basics

Citrix Presentation Server is the flagship product of Citrix Systems Inc. Citrix Presentation Server 4.0 is a part of the Citrix Access Suite 4.0. The other products of the Citrix Access Suite are Citrix Conference Manager, Citrix Password Manager, Citrix Access Gateway. Citrix Conference Manager is bundled free with the Citrix Presentation Server and is the only product that is dependent on the presence of Citrix Presentation Server. The other products can be installed, configured and managed independently. Briefly, the component of the Citrix Access Suite has the following functions:

Citrix Presentation Server – Presentation Server is used to make applications available to users and can be managed and configured centrally. The other features include load balancing, resource manager, network manager, installation manager.

Citrix Conference Manager – Citrix Conference Manager is used to facilitate application conferencing wherein the application file can be shared and used by multiple users simultaneously.

Citrix Password Manager – Single Sign On solution from Citrix

Citrix Access Gateway – SSL-VPN solution from Citrix which can be completely integrated with Citrix Presentation Server. The training session will focused on only one product of the Access Suite – Citrix Presentation Server. The Presentation Server comes in three editions. They are: 1. Standard – Application Management 2. Advanced – Application\3 Management & Load Balancing 3. Enterprise - Application Management, Load Balancing, Installation Manager, Resource Manager, Network Manager Briefly, the various functions of the editions can be described as follows:

1. Application Management – Application Management is the core functionality of the Presentation Server and is available across all its editions. It allows for deploying, configuring and managing applications and making them available to multiple users. The feature has been enhanced to also make single-user applications multi-user friendly.

2. Load Balancing – In Presentation Server, load balancing is the feature by which the user is directed towards the least loaded server. The server load is calculated on a set of criteria that are completely configurable by the administrators.

3. Installation Manager – It is the a feature which is used to package and deploy applications to all servers in a server farm

4. Resource Manager – It is the enhanced version of the Windows Server Performance Monitor. Apart from monitoring the CPU, Memory and Page File usage, the Presentation Server Resource Manager also tracks things like disk space, network cards, and connection to the data store etc. All the monitoring data can be collected for trend analysis in a database.

5. Network Manager – It is just a plug-in to other network manager tools like HP Openview.

To provide any or all the above functionality of the Presentation Server, the following components may or may not be required (the requirement of the component depends upon the functionality that is to be provided):
1. Presentation Server
2. Presentation Server Clients (Program Neighborhood, Program Neighborhood Agent, Web Client)
3. Web Interface Server
4. Data Store Server (may be on the same server as the Presentation Server but not preferred)
5. License Server (may be on the same server as the Presentation Server but not preferred)
The above components of the Presentation Server can be managed by the following tools:

1. Citrix Management Console – Used to publish applications, delegate administrators, define load-balancing parameters, deploy packed applications, configure policies, track the resource usage of the servers in a server farm. The entire configuration made through the Citrix Management console is stored in a data store. This console can be installed on any workstation and used by the administrator.

2. Access Suite Console – It is a java-based console. This console is primarily used to view alerts generated by applications and server, configure web interface server, configure program neighborhood Agent and Conference Manager. This is an integrated console for monitoring all the products of the Citrix Access Suite from a single console. This console can be installed on any workstation and used by the administrator.

3. ICA Toolbar : It is a collection of tools which allow the administrator to configure farm wide settings. Client update database, connection configuration tool, Shadow Taskbar etc are made available to the administrator through this toolbar.
4. License Management Console - Used to manage licenses being used by the various products of the Citrix Access Suite Console. Before we proceed further with the detailed discussion on the features of Presentation Server it is mandatory to explain certain terms and concepts of Citrix Technology.

Following is a brief description of the same:
IMA – Independent Management Architecture – it runs as a service. It is a collection of subsystems (*.dll) that communicate with each other to provide the services/ functions of the Presentation Server. It uses two ports – 2512 and 2513. 2512 is used as a port for communication between servers and 2513 is used as a port to communicate with the CMC.

Data Store – Data Store is a static collection of data. All server farm configurations are maintained in the data store which is only readable through the CMC. Data Store can be created on Oracle, IBM DB2, SQL, MSDE, and Access. Access is default (mf20.mdb). Access database or the MSDE database the method of accessing the database is indirect. For all other databases it is direct. The static information includes – Server Farm Name, List of published application, policies, servers in the farm, administrators of the farm and their rights, installable packages, load balancing rules.

Local Host Cache - Local copy of a subset of info stored in the data store. It is responsible for providing the services to the users when the connectivity to the data store has been lost.

Data Collector – Holds dynamic data – No. of active sessions, disconnected sessions, licenses used, load balancing information. Most Preferred, Preferred, Default Preference, Not Preferred.

Server Farm – Collection of servers sharing the same data store

Zone – Logical division of the Farm. Each zone has its own Data Collector. May or may not follow the subnet boundaries.

ICA – Connectivity protocol used by clients to connect to the server. Uses port 1494. It has 32 virtual channels which can enabled/disabled. There is a virtual channel for printing, audio, video. They can be turned off to make the channel thinner & facilitate optimum performance over slow WAN Links