wdisp/system

Value Range and Syntax

The character string has the following syntax:

          
wdisp/system_<xx> = SID=<sap-sid>, [MSHOST=<ms-host>, [MSPORT=<ms-http-port> | MSSPORT=<ms-https-port>] | SILOC=<info-file> | EXTSRV=<external-server-list>], [SRCSRV=<src-host>:<source-ports>,] [SRCURL=<source-urls>,] [NR=<scs-sys-no>,] [SCSHOST=<scs-host>]
            

You must specify the following options to describe the connected system.

• SID=<sap-sid>: Three letter SAP system ID

• Specifies where the Web Dispatcher obtains the meta information about the system.

  Normally, the Web Dispatcher fetches its metadata (which application servers are logged on, which services they provide, what capacity they have, and so on) from the message server of the connected system. Alternatively, you can also set up a file with the information, or configure the data to be forwarded to an external system.

  To do this, you have to specify one of the following variants:

  • MSHOST=<ms-host>, MSPORT=<ms-http-port>: The host name and HTTP port of the SAP Message Server that provides the information about the system in question. If you want to configure the metadata exchange through SSL, use option MSSPORT=<ms-httpS-port> to specify the HTTPS port of the message server. You then have to set parameter wdisp/server_info_protocol = HTTPS.

    More information: Metadata Exchange Using SSL

  • SILOC=<config-file-name>: Name of the configuration file containing the metadata of the system's application servers. The parameter corresponds to parameter wdisp/server_info_location for systems in which information is stored in a file.

    More information: Overview of Parameters

  • EXTSRV=<external-server-list>: You can use this to send requests to an external (non-SAP) system. The URLs, separated by semicolons in the list, are treated by the Web Dispatcher as instances of a system.

    Example

    wdisp/system_2 = SID=EXT, EXTSRV=http://websrv1:8080;http://websrv2:8888, SRCSRV=*:8093

    This sends all requests (“round robin”) arriving in port 8093 on to the two Web servers.

    Caution

    If an external system is configured with more than one server, you can only use stateless requests, since there is no mechanism in the Web Dispatcher for stickiness for external systems.

The remaining specifications are optional.

Description of HTTP Requests for this System

The following options specify which requests the Web Dispatcher forwards to this system. URL prefix and the host/port combination of the incoming request are available as criteria.

• SRCSRV=<source-services>: Specifies the possible host/port combinations in a list separated by semicolons: <source-services>= <host1>: <port1>[; <host2>: <port2>;…], whereby for host name and port the wild card character * can be used to specify every possible host name and port.

  Note

  Each port specified here is configured in the Web Dispatcher as the HTTP port (parameter icm/server_port_<xx>).

  Example

  • SRCSRV=*:8073 means: All requests arriving through the Web Dispatcher port 8073 should be forwarded to this system.

  • SRCSRV=*:8083;*:8073 means: All requests arriving through the Web Dispatcher ports 8073 and 8083 should be forwarded to this system.

• SRCURL=<source-url-prefixes> specifes the possible URL prefixes in a list separated by semicolons: <source-url-prefixes>=<prefix1>[;<prefix2>;…].

  If the incoming request contains one of the specified URL prefixes, the request is forwarded to this system.

  Example

  SRCURL=/sap/;/myapp/ means: Requests whose URL starts with “/sap/” or “/myapp/” are forwarded to this system.

Optional Specifications for the Connected System

• NR=<scs-sys-no> (optional): System number of the message server

  You can use the option NR to specify the SAP system number of the message server. This is required to identify the backend system in the System Landscape Directory (SLD), if the Web Dispatcher is to register with the SLD.

  Note

  Use the NR option to specify the system number of instance that contains the message server. This can be an SCS instance (AS Java), an ASCS instance (AS ABAP), or a classic central instance (DVEMGS).

• SCSHOST=<scs-host> (optional): Host name of the SCS instance.

  The option SCSHOST specifies the host name of the SCS instance, as does option MSHOST.

  Option SCSHOST is then only required if the host name specified in MSHOST does not correspond to parameter SAPLOCALHOST in the SCS instance (or central instance).

  In this case, option SCSHOST contains the value of parameter SAPLOCALHOST in the SCS instance (or central instance). The host name of the SCS instance is required for registering the Web Dispatcher in the SLD data model.