Citrix Virtual Apps Components
The following graphic shows a layer view of the Citrix Virtual Apps service components:
Citrix Workspace app is installed on user devices and other endpoints, such as virtual desktops. Citrix Workspace app provides users with secure, self-service access to documents, applications, and desktops from any device, including smartphones, tablets, and PCs. Citrix Workspace app provides on-demand access to Windows, web, and Software as a Service (SaaS) applications. For devices that cannot install Citrix Workspace app software, Citrix Workspace app for HTML5 provides a connection through a HTML5-compatible web browser.
Delivery Controller
The Delivery Controller is the central control layer component in a deployment. The Controller’s services communicate through the Cloud Connectors in each resource location to:
- Distribute applications and desktops.
- Authenticate and manage user access.
- Broker connections between users and their virtual desktops and applications.
- Optimize use connections, and load-balance these connections.
- Track which users are logged on and where, which session resources the users have, and if users need to reconnect to existing applications. This includes managing the state of desktops, starting and stopping them based on demand and administrative configuration.
Data from the Controller services is stored in a Microsoft SQL Server site database. A deployment also uses a configuration logging database, plus a monitoring database used by Director.
Citrix license management
License management functionality communicates with the Controller to manage licensing for each user’s session and allocate license files. There are 3 types of licenses: Platinum, Enterprise and Standard.
Citrix Studio
Studio is the management console you use to configure and manage connections, machine catalogs, and delivery groups.
Citrix Director
Director enables IT support and help desk teams to monitor an environment, troubleshoot issues before they become system-critical, and perform support tasks for end users. Displays include:
- Real-time session data from the Broker Service in the Controller, which includes data from the broker agent in the VDA.
- Historical data from the Monitor Service in the Controller.
- Data about HDX traffic (also known as ICA traffic).
Citrix StoreFront
Citrix StoreFront is the predecessor to Citrix Workspace, and is used in on-premises deployments. It offers several similar features to Citrix Workspace, including subscriber access to apps and desktops, authentication, and other subscriber data that ensures consistent experience across devices.
In a service deployment, you can optionally install StoreFront servers in resource locations. Having local stores can help deliver apps and desktops during network outages. The Local Host Cache feature requires a customer-managed StoreFront in each resource location (zone).
Citrix Gateway (NetScaler)
When users connect from outside the corporate firewall, Citrix Virtual Apps and Desktops can use Citrix Gateway technology to secure these connections with TLS. The Citrix Gateway or VPX virtual appliance is an SSL VPN appliance deployed in the DMZ. It provides a single secure point of access through the corporate firewall.
Virtual Delivery Agents (VDAs)
Each physical or virtual machine that delivers applications and desktops must have a VDA. The VDA registers with a Cloud Connector. After registration, connections are brokered from those resources to users. VDAs establish and manage the connection between the machine and the user device, and apply policies that are configured for the session.
The VDA communicates session information to the Cloud Connector through a broker agent in the VDA. The broker agent hosts multiple plug-ins and collects real-time data.
VDAs are available for Windows server and desktop operating systems. VDAs for Windows server operating systems allow multiple users to connect to the server at one time. VDAs for Windows desktop operating systems allow only one user to connect to the desktop at a time. Linux VDAs are also available.