Sap Web Dispatcher

SAP Web Dispatcher

The Web Dispatcher terminates/forwards HTTP(S) to the SAP back-end (message-server load balancing + SSL). Two deployment shapes:

• Instance-based (modern S/4): a real SAP instance W<nr> with sapstartsrv — driven by SAPControl exactly like any instance (sap-system-lifecycle).
• Standalone binary: the sapwebdisp executable + a profile, started/stopped directly.

Guardrail: it's internet-/user-facing — a stop drops all active HTTP sessions. Identify SID/host, classify PRD, confirm before bouncing. saprouttab-style access and SSL config are security-sensitive.

1. Start / stop / status

Instance-based (has sapstartsrv)

sapcontrol -nr <nr> -function Start          # start;  Stop / RestartSystem to stop / restart
sapcontrol -nr <nr> -function GetProcessList # status — the WEBDISP/ICMAN process GREEN

Standalone binary

# start (UNIX/Windows) — profile holds ports + backend systems:
sapwebdisp pf=<path>/sapwebdisp.pfl          # Windows: sapwebdisp.exe pf=…   [G, W1]
# stop — send SIGINT to the PID:
kill -2 <pid>            # UNIX (graceful)                                     [G, W1]
sapntkill -INT <pid>     # Windows                                            [G, W1]
# or, if installed as a Windows service: Services.msc → stop "sapwebdisp"

Useful start options [G, W1]: -f <tracefile>, -t <tracelevel>, -cleanup (release shared memory), -auto_restart, -shm_attach_mode, -version.

Status also via the admin UI: https://<host>:<https_port>/sap/wdisp/admin (see §3).

2. Ports

3. Profile essentials & admin UI

Minimum config in sapwebdisp.pfl / the instance profile: [G, W2]

SAPSYSTEMNAME = <SID>
icm/server_port_0 = PROT=HTTP,PORT=8000
icm/server_port_1 = PROT=HTTPS,PORT=44300
wdisp/system_0 = SID=<backendSID>, MSHOST=<msg-server-host>, MSPORT=81<nr>, SRCSRV=*:*, SRCURL=/
wdisp/ssl_encrypt = 1
icm/HTTP/admin_0 = PREFIX=/sap/wdisp/admin, DOCROOT=..., AUTHFILE=...

• wdisp/system_<n> defines each back-end system (message-server host/port for load balancing).
• Admin UI: /sap/wdisp/admin — status, back-end groups, trace level, restart. Protect with AUTHFILE.

4. Logs

dev_webdisp (main trace), dev_webdisp_log (start/stop/config), ICM-style HTTP access logs — details and trace levels (icm/trace_level, icm/HTTP/logging_<n>) in sap-log-reference → app-and-component-logs.

Cross-references

• Instance-style start/stop & order: sap-system-lifecycle.
• Health/status detail: sap-health-triage.
• Traces: sap-log-reference.

Run as the correct OS user

Identify the right OS user before running anything, and switch with a login shell. Wrong-user execution is a top cause of SAP failures, and the damage outlives the command: files created by root under /usr/sap, /sapmnt or a DB directory break every later start by the real owner. A login shell also matters because each user carries the environment the tools need (SAPSYSTEMNAME, ORACLE_HOME/ ORACLE_SID, SYBASE, DB2INSTANCE, library paths) — without it, commands fail or act on the wrong system.

Rules

• Switch with a login shell: su - <user> (the - is what loads the environment) or sudo -iu <user>. Windows: use the correct account, or an elevated shell only where documented.
• root only where the procedure explicitly says so — e.g. saproot.sh after a kernel extract, SAP Host Agent install/upgrade. Never as a shortcut around a permission error; that is how root-owned files get created and break the system later.
• Verify before acting: whoami / id, plus the env actually being set (echo $SAPSYSTEMNAME, echo $ORACLE_SID, echo $DB2INSTANCE, echo $SYBASE).
• State the user in every command you hand over (e.g. "as <sid>adm:"), and if the required user is not available, say so and stop — do not substitute another user.

Staying current — check SAP Notes first

SAP Notes supersede this file. Landscapes differ by release, patch level, DB and OS, and SAP changes procedures via Notes/KBAs between doc revisions.

If the SAP Notes MCP is configured, use it before acting on anything version-specific — especially any destructive step, or when a command here doesn't behave as documented:

1. search the topic (e.g. the component + symptom, or a Note number cited below).
2. fetch the promising Note IDs for the current text, validity (affected releases/components), prerequisites and side effects.
3. Prefer the Note over this file where they disagree, and say which Note you followed.

No MCP available? Look the Note up on me.sap.com/notes/<id> and say the check was skipped rather than assuming this file is current.

Sources

• [W1] Starting and Stopping Web Dispatcher — SAP Help Portal (sapwebdisp pf=…; stop via kill -2 / sapntkill -INT / service; options -cleanup/-auto_restart/-f/-t). https://help.sap.com/doc/329ac769552a411b97bc7adb991b6197/3.0.12/en-US/eae7d26b822e4b1facc275f25b4f03a2.html
• [W2] Operating / Installing and Configuring the SAP Web Dispatcher — SAP Help Portal (profile, icm/server_port, wdisp/system, /sap/wdisp/admin). SAP NetWeaver AS documentation.

To confirm/deepen: the SAP Web Dispatcher guide for your release (profile parameter reference) and, for instance-based deployments, sap-system-lifecycle.