The SAP Web Dispatcher Profile Parameter
The following overview describes the profile parameter within the SAP Web dispatcher.
Use
The default values were selected so that you do not have to make any changes to these parameters. You determine the point of access to your SAP system using parameter
icm/server_port_<xx>.You can however use the parameters to adapt the configuration to specific system requirements.
See also:
Example: Profile File of a SAP Web DispatcherPrerequisites
Since the SAP Web dispatcher connects itself to the SAP message server and communicates with it via HTTP, the following parameters must be set correctly in the SAP Web dispatcher profile.
Procedure
The following describes the parameters that you can use to configure the SAP Web dispatcher. You can also find the parameters and documentation in Transaction RZ11.
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Parameters |
Meaning |
Unit |
Default Value |
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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 |
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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 |
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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 |
|
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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 |
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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 |
|
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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 |
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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 |
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wdisp/server_info_location |
Specifies where the SAP Web dispatcher obtains information about the SAP Web Application Server, to which it can distribute the Web requests. |
Character string |
/msgserver/ text/logon |
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wdisp/group_info_location |
Specifies where the SAP Web dispatcher obtains information about the server groups, to which it can distribute the Web requests. |
Character string |
/sap/public/ icf_info/icr_groups |
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wdisp/url_map_location |
Path in the HTTP service tree (Transaction SICF), under which the URL mapping info for the SAP Web dispatcher is stored. |
URL path name |
/sap/public/ icf_info/icr/urlprefix |
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wdisp/server_info |
You can use these parameters for testing purposes. You can use them to have the SAP Web dispatcher fetch information about the servers, server groups and URL mappings that are available from files and not from the system (message server or application server). You can then use these parameters to specify the corresponding path name. |
Path name (corresponds to the operating system convention) |
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wdisp/group_info |
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wdisp/url_map_info |
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Wdisp/HTTPS/dest_logon_group |
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 names |
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wdisp/HTTPS/sticky_mask |
This parameter describes a bit mask for client IP addresses. A client’s IP address, which connects with the Web dispatcher, is linked using this bit mask (AND) and the result is used for load balancing clients. 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 with server 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). |
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wdisp/HTTPS/max_client_ip_entries |
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 created in the host’s shared memory.
The following specifies examples of memory requirements with specific settings. |
Number of entries (integer value) |
50000 |
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10000 entries |
1.8 MB |
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50000 entries |
8.9 MB |
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100000 entries |
17.8 MB |
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1048576 entries |
230 MB |
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16777216 entries |
3000 MB |
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wdisp/HTTP/max_pooled_con |
This parameter determines the maximum number of HTTPS 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 |
|
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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 |
|
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wdisp/HTTPS/max_pooled_con |
This parameter determines the maximum number of HTTPS 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 |
|
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wdisp/HTTPS/min_pooled_con |
Minimum number of HTTPS connections that are kept in the SAP Web dispatcher’s connection pool for each application server. These connections are kept before the first HTTPS request is received.
Since for each HTTP connection in the pool on the Web AS page, a thread is blocked in the ICM, you should not change the default value of 0! |
Number of connections |
0 |
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When you set the maximum values, note that unnecessarily large values can increase the SAP Web dispatcher’s memory consumption.
You can find a rule of thumb for memory consumption in
SAP Web Dispatcher.You can find an example of a profile file in
Example: Profile File of a SAP Web Dispatcher. Minimal Configuration for the SAP Web Dispatcher describes a minimal configuration for the SAP Web Dispatcher.
This parameter is only relevant when using HTTPS!