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The following SAP Web Dispatcher parameters are relevant for running the Dispatcher with SSL.

For more information see SAP Web Dispatcher and SSL.

The other profile parameters are described in Parameterization of the SAP Web Dispatcher.

Parameter

Meaning

Unit

Default value

wdisp/HTTPS/dest_logon_group

Note Note

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

End of the note.

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

Note Note

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

End of the note.

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

Note Note

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

End of the note.

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.

Example Example

The following table specifies examples of memory requirements with specific settings.

Number of Entries in the Mapping Table

Required Memory Space

10000 entries

1.8 MB

50000 entries

8.9 MB

100000 entries

17.8 MB

1048576 entries

230 MB

16777216 entries

3,000 MB

End of the example.

Number of entries (integer value)

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.

Caution Caution

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 Java request.

End of the caution.

Seconds

3600

wdisp/HTTPS/max_pooled_con

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

Note Note

What is important here is which protocol is used from the SAP Web Dispatcher to the application server.

End of the note.

Recommendation Recommendation

You do not normally need to change the default setting.

End of the recommendation.

Number of connections

32768

wdisp/HTTPS/min_pooled_con

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

Note Note

What is important here is which protocol is used from the SAP Web Dispatcher to the NetWeaver AS.

End of the note.

Caution Caution

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

End of the caution.

Number of connections

0

wdisp/ssl_encrypt

This parameter determines how the SAP Web Dispatcher handles inbound HTTP 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.

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.

Integer (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.

Integer (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.

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).

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.

Example Example

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.

End of the example.

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/ssl_ignore_host_mismatch

If the connection between the Web Dispatcher and application server is re-encrypted (wdisp/ssl_encrypt=1=1), the server must produce an SSL server certificate before the connection can be opened. If the host name in the certificate does not match the server name the Web Dispatcher is connected to (names are not case-sensitive), no SSL connection can be established.

Example Example

The certificate is issued on sdm.int.sap.com. The application server, however, runs on the internal host with the name ld5000.wdf.sap.corp (and it is also logged on with this name to the message server).

End of the example.

If this parameter is now set to 1 or TRUE, the Web Dispatcher ignores the missing match between the server certificate and the server host name, and uses this newly opened SSL connection between the Web Dispatcher and the server for the communication.

Logical value (TRUE, FALSE, 1, 0)

FALSE

SSL (Re)Encryption: Connection Pooling

To increase system performance when using SSL (re)encryption, you can activate Connection Pooling by setting parameter wdisp/HTTP/use_pool_for_new_conn = 1.