Parameter

Meaning

Unit

Default Value

icm/server_port_<xx>

Starting point for requests, protocols, timeouts, etc.

You have to define this parameter.

Character string

-

wdisp/auto_refresh

The period of time after which the route information tables of the SAP Web dispatcher (server tables, group tables and URL mapping tables) are periodically updated.

Seconds

120

wdisp/max_servers

This parameter determines the maximum number of entries in the SAP Web dispatcher’s server table.                          

Whole number (between 64 and 4096)

128

wdisp/max_server_name_len

This parameter specifies the maximum length of an entry in the SAP Web dispatcher’s server table, that is, the maximum length of an instance name (profile parameter rdisp/myname of the individual servers).

Whole number (between 32 and 128)

64

wdisp/max_server_groups

This parameter determines the maximum number of entries in the SAP Web dispatcher’s group table.

Whole number (between 32 and 4096)

128

wdisp/max_server_group_name_len

This parameter determines the maximum length of an entry in the SAP Web dispatcher’s group table.

You maintain logon groups in transaction SMLG.     

Whole number (between 20 and 64)

20

wdisp/max_url_map_entries

This parameter determines the maximum number of entries in the SAP Web dispatcher’s URL mapping table.       

Whole number (between 100 and 10000)

300

wdisp/max_url_map_path_len

This parameter determines the maximum path length in the SAP Web dispatcher’s URL mapping table.                                

Whole number (between 100 and 2048)

256

wdisp/server_info_location

Specifies from where the SAP Web dispatcher obtains information about the SAP Web Application Server, to which it can distribute the Web requests.

The SAP Web Dispatcher gets its information from the Message Server. The parameter indicates the (relative) URL where in the Message Server this information is.

Character string

/msgserver/

text/logon

wdisp/group_info_location

Specifies from where the SAP Web dispatcher obtains information about the server groups, to which it can distribute the Web requests.

The details are indicated in a URL (absolute or relative).

Usually the SAP Web Dispatcher gets its group information from an application server (transaction SMLG). In this case you can specify the ICF service, where the groups are defined.

If there is no application server with ICF (ABAP) available, you can store this information in a file. In this case you can use this parameter to specify the file path by setting the parameter to file://<path>.

Character string

/sap/public/

icf_info/

icr_groups

wdisp/url_map_location

URL under which the SAP Web Dispatcher finds the URL mapping info.

This is usually a path in the HTTP service hierarchy of the application server (transaction SICF).

If there is no application server with ICF (ABAP) available, you can store this information in a file. In this case you can use this parameter to specify the file path by setting the parameter to file://<path>.

URL path name

/sap/public/

icf_info/icr_

urlprefix

wdisp/server_info_protocol

wdisp/group_info_protocol

wdisp/url_map_protocol

Protocol that the SAP Web Dispatcher should use for communicating with the message server and the application servers for exchanging metadata (server list, logon groups, URL mapping).

With HTTPS you can make this communication secure, see Metadata Exchange Using SSL.

Protocol name, possible values: HTTP or HTTPS

HTTP

wdisp/permission_table

Absolute or relative path for URI permission table. Further profile parameters for configuring the URI permission table are described in section SAP Web Dispatcher as URL Filter.

Character string (file path)

Wdisp/HTTPS/dest_logon_group

This parameter is only relevant when using End-to-End SSL

This parameter determines the logon group for load balancing requests at the SAP Web dispatcher. If a logon group is defined, the requests are passed to the servers in this group only. If no group is defined, the requests can be passed to all of the servers in the system.

You maintain logon groups in transaction SMLG in the system.

Logon group name

wdisp/HTTPS/sticky_mask

This parameter is only relevant when using End-to-End SSL

This parameter describes a bit mask for client IP addresses. The result of the bitwise AND operation on the client’s IP address and the sticky mask is used for load balancing of clients.                   

This way you can summarize groups of client IP addresses.

This functionality is required because large internet providers use several proxies (with different IP addresses) but the clients must be handled in the same way. This is imperative for applications for which the server keeps a status (stateful applications).                                         

Character string

255.255.240.0                                   

The last 12 bits of the client IP address are no longer significant (are not distinguished).                     

wdisp/HTTPS/

max_client_ip_entries

This parameter is only relevant when using End-to-End SSL

This parameter specifies the maximum number of entries in the mapping table between the client IP address and the application server.                                                 

The memory for the mapping table is allocated in the host’s shared memory.                                             

Anzahl Einträge (Integerwert)

50000

wdisp/HTTPS/context_timeout

This parameter specifies the timeout for entries in the client IP table in seconds (default 3600). An entry is deleted from the table, if no request has arrived from this client IP address within the specified time span.

The value of this parameter must always be bigger than the session timeout of the application server. This value depends on whether it is an ABAP or a J2EE request.

·        ABAP: Profile parameter rdisp/plugin_auto_logout, see parameter documentation.

·        J2EE: See Specifying HTTP Session Timeout for Web applications and Additional Configuration Settings using the Visual Administrator.

Seconds

3600

wdisp/HTTP/max_pooled_con

This parameter determines the maximum number of HTTP connections in the connection pool from the SAP Web dispatcher to an SAP Web Application Server.                                                           

You do not normally need to change the default setting.  

Number of connections

32768

wdisp/HTTP/min_pooled_con

Minimum number of HTTP connections that are kept in the SAP Web dispatcher’s connection pool for each application server. This number of connections is kept before the first HTTP request is received.                                       

Number of connections

2

wdisp/HTTPS/max_pooled_con

This parameter is the same as wdisp/HTTP/max_pooled_con, though for HTTPS connections.

What is important here is the protocol used from the SAP Web dispatcher to the Web AS. See SAP Web Dispatcher and SSL.

You do not normally need to change the default setting.  

Number of connections

32768

wdisp/HTTPS/min_pooled_con

This parameter is the same as wdisp/HTTP/min_pooled_con, though for HTTPS connections.

What is important here is the protocol used from the SAP Web dispatcher to the Web AS. See SAP Web Dispatcher and SSL.

Since for each HTTP connection in the pool on the Web AS, a thread is blocked in the ICM, you should not change the default value of 0!                                                 

Number of connections

0

wdisp/ssl_encrypt

This parameter determines how the SAP Web dispatcher handles inbound HTTP(S) requests. The following values are permitted:

0: Forward the request unencrypted.                        

1: Encrypt the request again with SSL, in case the request arrived via HTTPS protocol.                                  

2: Always forward the request encrypted with SSL.        

The parameter corresponds to the SSLENC option of the ICM parameter icm/HTTP/j2ee_<xx>

You can also configure the SAP Web dispatcher for End-to-End SSL, by specifying the protocol ROUTER when you define the icm/server_port_<xx> parameter.               

Whole number (0, 1 or 2)

0

wdisp/ssl_auth

This parameter determines which X.509 client certificate of the SAP Web dispatcher can be used with which application servers.  

The following values are permitted:

0: No certificate 

1: Default certificate  

2: Use the certificate specified in the wdisp/ssl_cred parameter.                              

The parameter corresponds to the TYPE option of the ICM parameter icm/HTTP/j2ee_<xx>

Whole number (0, 1 or 2)

0

wdisp/ssl_cred

Name of the PSE file used for the server authentication. This option is only relevant if wdisp/ssl_auth =2.

The parameter corresponds to the CRED option of the ICM parameter icm/HTTP/j2ee_<xx>

File name/path name (corresponds to the operating system convention)

wdisp/ssl_certhost

This parameter is only relevant, if you have configured a connection with SSL, that is, either the connection to the message server (wdisp/server_info_protocol = https), to the application servers (wdisp/group_info_protocol=https or wdisp/url_map_protocol=https. Compare Metadata Exchange Using SSL), or the parameter is relevant for SSL termination (wdisp/ssl_encrypt = 1 or 2). For more information see SAP Web Dispatcher and SSL.

If wdisp/ssl_certhost is not defined, for each application server a server certificate must be set up on the relevant host.

In this parameter you can specify a host on which the server certificate is issued. Then you do not have to provide a certificate for each application server.                                   

Your server certificate is issued on the name "www.sap.com". You activate this certificate for all application servers in transaction STRUST. You also set the value of wdisp/ssl_certhost to www.sap.com.

If this parameter is not set, the host names on the message server (transaction SMLG) and the names the certificates are issued with must be the same.                                 

Host name

wdisp/load_balancing_strategy

Load balancing strategy of the SAP Web dispatcher, see Server Selection and Load Balancing Using the SAP Web Dispatcher

Load balancing strategy

Possible values:

weighted_round_robin

simple_weighted_round_robin

adaptive

weighted_round_robin

wdisp/add_xforwardedfor_header

The parameter determines whether the SAP Web dispatcher includes the IP address of the client in the header field x-forwarded-for. If it does, the application on the application server can read the route that the request has taken. If the parameter has the value false, the Web dispatcher leaves the header field unchanged.

Truth variable (true or false)

false

wdisp/add_client_protocol_header

This parameter determines whether the protocol between the browser and the Web dispatcher (HTTP or HTTPS) is notified to the application server.

This information is sent in the header field. clientprotocol.

If there is a change in protocol in the Web dispatcher, the application server requires this information, to generate absolute URLs (it can get the Web dispatcher host and port names from the header field Host).

Truth variable (true or false)

false

wdisp/enable_sap_hostid

If the value of this parameter is true, a server destination can be specified explicitly in the request URI using the form field sap-hostid, to directly override the load balancing.

This is needed, for example, for debugging server nodes or for test purposes.

webdisp.wdf.sap.corp:4711/sap/public/icman/ping?sap-hostid=binmain_BIN_53

Since with this form field server load balancing can be bypassed (denial of service attacks), the default is this behavior is deactivated and must be explicitly activated using the parameter above.

Truth variable (true or false)

false

wdisp/redispatch_foreign_sessions

If the value of this parameter is true, the Web dispatcher tries to find an alternative server using stateless load balancing for failed stateful requests (incorrect session cookie in target server cannot be accessed).

This has the following advantages:

The relevant backend (J2EE, ABAP) returns more error pages, such as "Please log on again".

The Web dispatcher remains transparent for the user.

A real session failover is made possible, if the relevant server backend is in the position to transfer external sessions.

For security reasons this feature must also be explicitly activated in the above profile parameter.

Truth variable (true or false)

false