The XenApp 7.5 now moves to the FlexCast Management Architecture (FMA) as same as XenDesktop, brings conceptual and more flexible architecture. Here are the differences between XenApp 6 entities and terminology in a XenApp 7.5 world.

FlexCast Management Architecture

The FlexCast Management Architecture (FMA) is a service-oriented architecture that allows interoperability and management modularity across Citrix technologies. FMA provides a platform for application delivery, mobility, services, flexible provisioning, and cloud management.

FMA replaces the Independent Management Architecture (IMA) used in XenApp 6.x

Elements in the new architecture

Delivery Sites

Farms were the top level objects in XenApp 6.x. In XenApp 7.5, the Delivery Site is the highest level item. Sites offer applications and desktops to groups of users.

The FMA requires that you must be in a domain to deploy a site. For example, to install the XenApp servers, your account must have both local administrator privileges and be a Domain Administrator in the Active Directory.

Session Machine Catalogs and Delivery Groups

Machines hosting applications in XenApp 6.x belonged to Worker Groups for efficient management of the applications and server software. Administrators could manage all machines in a Worker Group as a single unit for their application management and load balancing needs. Folders were used to organize applications and machines.

In XenApp 7.5 we use a combination of Session Machine Catalogs and Delivery Groups to manage machines, load balancing, and hosted applications or desktops.

A Session Machine Catalog is a collection of machines that are configured and managed alike. A machine belongs to only one catalog. The same applications or desktops are available on all machines of the catalog.

Delivery Groups are designed to deliver applications and desktops to users. A Delivery Group can contain machines from multiple machine catalogs, and a single machine catalog can contribute machines to multiple Delivery Groups. However, one machine can belong to only one Delivery Group. You can manage the software running on machines through the catalogs they belong to. Manage user access to applications through the Delivery Groups.

Virtual Delivery Agents

The Virtual Delivery Agent (VDA) enables connections to applications and desktops. The VDA is installed on the machine that runs the applications or virtual desktops for the user. It enables the machines to register with Delivery Controllers and manage the High Definition eXperience (HDX) connection to a user device.

In XenApp 6.5, worker machines in Worker Groups ran applications for the user and communicated with data collectors. In XenApp 7.5, the VDA communicates with Delivery Controllers that manage the user connections.

The VDA installs on Server OS machines and Desktop OS machines

Delivery Controllers

In XenApp 6.x there was a zone master responsible for user connection requests and communication with hypervisors. In XenApp 7.5 connection requests are distributed and handled by the Controllers in the site. XenApp 6.x zones provided a way to aggregate servers and replicate data across WAN connections. Although zones have no exact equivalent in XenApp 7.5, we can provide users with applications that cross WANs and locations. You can design Delivery Sites for a specific geographical location or data center, and then allow users access to multiple Delivery Sites. App Orchestration with XenApp 7.5 provides capabilities for managing multiple sites in multiple geographies.

Citrix Studio and Citrix Director

Citrix Studio console is used to configure the environments and provide users with access to applications and desktops. Studio replaces the Delivery Services Console and AppCenter in XenApp 6.x.Administrators use Director to monitor the environment, shadow user devices, and troubleshoot IT issues.

Delivering applications

XenApp 6.x used the Publish Application wizard to prepare applications and deliver them to users. In XenApp 7.5, you use Studio to create and add applications to make them available to users who are included in a Delivery Group. Using Studio, you first configure a site, create and specify machine catalogs, and then create Delivery Groups within those machine catalogs. The Delivery Groups determine which users have access to the applications you deliver.

Database

XenApp 7.5 does not use the IMA data store for configuration information. It uses a Microsoft SQL Server database to store configuration and session information and no more support for MS Access and Oracle databases.

Load Management Policy

In XenApp 6.5, load evaluators use predefined measurements to determine the load on a machine. User connections can be matched to the machines with lesser load. In XenApp 7.5, use load management policies for balancing load across machines.

Delegated Administrators

In XenApp 6.5, we created custom administrators and assigned them permissions based on folders and objects. In XenApp 7.5, custom administrators are based on role and scope pairs. A role represents a job function and has defined permissions associated with it to allow delegation. A scope represents a collection of objects. Built-in administrator roles have specific permissions sets, such as help desk, applications, hosting, and catalog. For example, help desk administrators can work only with individual users on specified sites, while full administrators can monitor the entire deployment and resolve system-wide IT issues.