Product Documentation

AppExpert Applications and Templates

Jan 04, 2016

An AppExpert application is a collection of configuration information that you set up on the Citrix NetScaler appliance for securing and optimizing traffic for a Web application, such as Microsoft SharePoint. Managing AppExpert applications is simplified by a graphical user interface (GUI) that allows you to specify application traffic subsets and a distinct set of security and optimization policies for processing each traffic subset. Additionally, it consolidates all deployment tasks in one view, so you can quickly configure target IP addresses for clients and specify host servers.

Prebuilt application templates for widely used Web applications, such as Microsoft Outlook Web Access and Microsoft SharePoint, are available on the AppExpert Templates page of the Citrix Community website at "http://community.citrix.com/display/ns/AppExpert+Templates."

Each prebuilt template provides you with an initial configuration for managing the associated Web application. You can customize prebuilt application templates for your organization. If a prebuilt application template does not suit your requirements, you can create a custom application without using a template.

Regardless of whether you use a prebuilt application template or you create a custom application, you can export the configuration to a template file. You can then share the template with other administrators or import the template to other NetScaler appliances that require a similar AppExpert application configuration.

To get started with an AppExpert application, you must first obtain the appropriate application template and import the template to the NetScaler appliance. After the AppExpert application is set up, you must verify that the application is working correctly. If required, you can customize the configuration to suit your requirements.

Periodically, you can verify and monitor the configuration by viewing the hit counters for various application components, statistics, and the Application Visualizer. You can also configure authentication, authorization, and auditing (AAA) policies for the application.

AppExpert Application Terminology

Updated: 2013-08-30

Following are the terms used in the AppExpert applications feature and the descriptions of the entities for which the terms are used:

Public Endpoint. The IP address and port combination at which the NetScaler appliance receives client requests for the associated web application. A public endpoint can be configured to receive either HTTP or secure HTTP (HTTPS) traffic. All client requests for the web application must be sent to a public endpoint. An AppExpert application can be assigned multiple endpoints. You configure public endpoints after you import a template.

Application Unit. An AppExpert application entity that processes a subset of web application traffic and load balances a set of services that host the associated content. The subset of traffic that an application unit must manage is defined by a rule. Each application unit also defines its own set of traffic optimization and security policies for the requests and responses that it manages. The NetScaler services associated with these policies are Compression, Caching, Rewrite, Responder, and application firewall.

By default, every AppExpert application with at least one application unit includes a default application unit, which cannot be deleted. The default application unit is not associated with a rule for identifying requests and is always placed last in the order of application units. It defines a set of policies for processing any request that does not match the rules that are configured for the other application units, thereby ensuring that all client requests are processed.

Application units and their associated rules, policies, and actions are included in AppExpert application templates.

Service. The combination of the IP address of the server that hosts the web application instance and the port to which the application is mapped on the server, in the format <IP address>:<Port>. A web application that serves a large number of requests is usually hosted on multiple servers. Each server is said to host an instance of the web application, and each such instance of the web application is represented by a service on the NetScaler appliance. Services are deployment-specific, and are therefore not included in templates. You must configure services after you import a template.

Application Unit Rule. Either a classic expression or a default syntax expression that defines the characteristics of a traffic subset for an application unit. The following example rule is a default syntax expression that identifies a traffic subset that consists of four image types:

HTTP.REQ.URL.SUFFIX.EQ("bmp") || HTTP.REQ.URL.SUFFIX.EQ("gif") || HTTP.REQ.URL.SUFFIX.EQ("png") || HTTP.REQ.URL.SUFFIX.EQ("jpg")

For more information about default syntax expressions and classic policy expressions, see "Policies and Expressions."

Traffic Subset. A set of client requests that require a common set of traffic optimization and security policies. A traffic subset is managed by an application unit and is defined by a rule.