Monitoring Web Dynpro Applications with Console Commands 

Use

The console commands described here can be used to check and monitor Web Dynpro applications, for example if errors occur.

The use of console commands is one way to perform monitoring. Other options for system monitoring are provided by the Visual Administrator of the J2EE Engine.

For a description of the Visual Administrator, see the SAP Library at SAP NetWeaver ® Application Platform (SAP Web Application Server) ® J2EE Technology in SAP Web Application Server ® Administration Manual ® Server Administration ® SAP J2EE Engine Administration Tools ® Visual Administrator.

In order to enter console commands, the console must be started. To find out how to call the console, read about connecting and working with Telnet. For information on this topic see the Administration Manual in the SAP Library under SAP NetWeaver ® Application Platform (SAP Web Application Server) ® J2EE Technology in SAP Web Application Server ® Administration Manual ® Server Administration ® SAP J2EE Engine Administration® Administration Services ® Telnet Administration ® Connecting and Working Using Telnet.

Prerequisites

In order to use the console commands the console must be started as described in the section on connecting and working with Telnet. You can find the path to this description in the above section.

Features

The Web Dynpro commands are provided in the console by entering the command add webdynpro. You can then display an overview of the available commands by entering man webdynpro. The syntax for using the Web Dynpro commands is:

      webdynpro <action> <parameters>

Parameter <parameters> is the name of the Web Dynpro application.  With the parameter for <action> you can perform the following functions:

·        get [<depl_object_name>]

Indicates which Web Dynpro archive or applications are known to the J2EE Engine.

·        getrefs

Lists the archive references to other references or libraries.

·        getpaths

Lists the paths to private resources, public resources, and Web resources.

·        getstate

Shows the state of the Web Dynpro archive at the moment. The following states are possible:

¡        stopped

¡        started

¡        starting

¡        unknown

Actions

Use the following syntax when entering console commands:

webdynpro <action> <parameters>

Example

webdynpro getstate SPICE

(SPICE = Name of the application)

Other Console Commands Providing Support if Problems Occur

Further console commands that you can use to analyze problems occurring in connection with deployed Web Dynpro applications are described below.

To activate the following console commands, you must first enter the command

add deploy.

Such problems are for example:

·        You cannot start a deployed Web Dynpro application
With the command list_app you can display the list of all currently deployed Web Dynpro applications. In addition to the name of the application, the list contains the status of the application. If the status of an application is STOPPED, the application can be started with the console command start_app <application name>. If this does not work, the reason might be that the Web Dynpro application defined runtime references that the J2EE Engine could not access.  You see that there is a reference that cannot be accessed if you cannot start the application.  You can check this by entering the command add webdynpro followed by webdynpro getrefs <application name>. The list that is displayed shows all the references that were defined by the Web Dynpro application. This list also includes the status of the references. If the status of a reference is not OK, the application cannot be started.

¡        With the command lss (the abbreviation stands for list services) you get a list of the services that are currently deployed.

¡        With the command lsl (the abbreviation stands for list libraries) you get a list of the deployed libraries.

¡        With the command lsi (the abbreviation stands for list interfaces) you get a list of the deployed interfaces.
You can correct the problem either by changing the definition of the references in the application or by deploying the missing referenced components to the J2EE Engine.

·        The Web Dynpro application ends with a runtime exception error message that classes or resources were not found
In this case, check the class loader of the application.
With the command llr <application name> (the abbreviation stands for list loader) the class loader is displayed. The class loader contains the definition of all the paths and references to which the Web Dynpro application has access. Check if the resource you need is contained in one of the paths. If this is not the case, check if the Web Dynpro application needs a further reference to a library, service or interface.

·        All the Web Dynpro applications have status STOPPED:
Check if the Web Dynpro service, that is the Web Dynpro runtime environment, is correctly deployed and is ready for use. Enter the command lss (the abbreviation stands for list services). The list should contain the entry webdynpro for Web Dynpro and the corresponding status should be STARTED.
If this is not the case, the Web Dynpro runtime environment was not correctly installed. If this is the case, check the status of the system applications, which must always exist. With list_app you get an overview of the applications currently deployed. The list should contain sap.com/tc~wd~dispwda and the status should be STARTED. If this is not the case, the Web Dynpro runtime environment was not correctly installed.