2338777 - Avoid having users accessing ICM and redirect to SAP Web Dispatcher

Symptom

For the query on using SAP Web Dispatcher and avoid the users' directly in ICM, the Resolution section provide the details.

If a wrong redirect is made in the ICM side, it is possible that SAP Web Dispatcher, in front of ICM, stop connecting to the ICM reporting errors like:

*** WARNING => Failed to read group info for system <SID> (ABAP,HTTP): Internal ICM error(-1) [icrxx.c 3762]
*** WARNING => Failed to read URL prefix info for system <SID> (ABAP,HTTP): Internal ICM error(-1) [icrxx.c 3762]

Errors with a high trace level are listed as below,

NiICheckPendConnection: connection of hdl 704 to <dest IP>:<port> established
NiIConnect: hdl 704 took local address <source IP>:<port>
NiIConnect: state of hdl 704 NI_CONNECTED
NiIWrite: hdl 704 sent data (wrt=93,pac=1,RAW_IO)
NiIRead: hdl 704 recv would block (errno=EAGAIN)
NiIRead: hdl 704 received data (rcd=376,pac=1,RAW_IO)
IcrIHandleHTTPClientRequest: received response: len = 376
ICT: IctIHttpOpenMessage: 120acf30 typ=2
ICR: HTTP response error code = 307
ICT: IctHttpCloseMessage( 120acf30 ) -> u=0 rc=0
NiICloseHandle: shutdown and close hdl 704/sock 90
IcmConnClientRqFree: Connection 2/64302 closed
IcmConnFreeContext: context 1 released
IcrIHandleHTTPClientRequest: dest=<hostname>:<port>' URL='/sap/public/icf_info/icr_groups?version=2.2' -> -1
HTR: decrement load factor: 80 -> 0 (d=80)
ICR: IcrDetachFromServer -> 0
ICR, system WMW: IcrIHandleHTTPClientRequest failed: Internal ICM error(-1), retry=3

In the browser error "503 Service not available" be reported or even a message like "server is redirecting the request for this address in a way that will never complete."

These are examples of wrong redirections made in ICM side that affect the SAP Web Dispatcher behavior.

Environment

SAP NetWeaver Systems
SAP Web Dispatcher

Keywords

Webdispatcher, HTTP response modification, handler rewrite, header rewriting, Internet Communication Manager, icm/HTTP/mod_<xx>, icm/HTTP/mod_0, RegRedirectUrl, redirect connection to Web Dispatcher, avoid directly connections to ICM , KBA , BC-CST-WDP , Web Dispatcher , BC-CST-IC , Internet Communication Manager , Problem

About this page

This is a preview of a SAP Knowledge Base Article. Click more to access the full version on SAP for Me (Login required).

Search for additional results

Visit SAP Support Portal's SAP Notes and KBA Search.