SAP Web Dispatcher to EXTSVR site

[curtis_mackenzie2]

Hi.

I'm having problems getting the SAP Web Dispatcher to redirect to an internal IIS site.  THe Web dispatcher is setup to terminate the SSL connection and redirect to internal SAP servers which is working perfectly but I would like to add the EXTSRV option as seen below and i cant seem to get it to work.

Does anyone have any ideas to try or perhaps what I'm trying is not possible?

~~~~~~~~~~~~~~Profile~~~~~~~~~~~~~~~~~~

SAPSYSTEMNAME = WP1

SAPGLOBALHOST = SAPWebDispatcher

SAPSYSTEM = 00

INSTANCE_NAME = W00

DIR_CT_RUN = $(DIR_EXE_ROOT)\$(OS_UNICODE)\NTAMD64

DIR_EXECUTABLE = $(DIR_CT_RUN)

DIR_PROFILE = $(DIR_INSTALL)\profile

_PF = $(DIR_PROFILE)\WP1_W00_SAPWebDispatche

SETENV_00 = PATH=$(DIR_EXECUTABLE);%PATH%

#-----------------------------------------------------------------------

# Configuration for medium scenario

#-----------------------------------------------------------------------

icm/max_conn = 500

icm/max_sockets = 1024

icm/req_queue_len = 500

icm/min_threads = 10

icm/max_threads = 50

mpi/total_size_MB = 80

#-----------------------------------------------------------------------

# SAP Web Dispatcher Ports

#-----------------------------------------------------------------------

icm/server_port_0 = PROT=HTTP,PORT=0

icm/server_port_1 = PROT=HTTPS,PORT=443

icm/server_port_2 = PROT=HTTPS,PORT=6666

icm/HTTPS/verify_client = 0

icm/HTTP/admin_0 = PREFIX=/sap/admin,DOCROOT=$(DIR_DATA)$(DIR_SEP)icmandir,AUTHFILE=$(icm/authfile),PORT=6234

icm/HTTP/mod_0 = PREFIX=/,FILE=C:\usr\sap\WP1\W00\sec\icm_filter.pfl

#-----------------------------------------------------------------------

# Start webdispatcher

#-----------------------------------------------------------------------

_WD = $(DIR_EXECUTABLE)\sapwebdisp$(FT_EXE)

Start_Program_00 = local $(_WD) pf=$(_PF)

sec/libsapsecu = $(ssl/ssl_lib)

ssf/ssfapi_lib = $(ssl/ssl_lib)

SETENV_01 = SECUDIR=$(DIR_INSTANCE)/sec

is/HTTP/default_root_hdl = abap

wdisp/permission_table = C:\usr\sap\WP1\W00\sec\urlfilter.pfl

wdisp/ssl_encrypt = 0

wdisp/add_client_protocol_header = true

wdisp/system_0 = SID=ZP1, MSHOST=MySAPServer.domain.com, MSPORT=8100

wdisp/system_1 = SID=EXT, EXTSRV=https://MyInternalSite.Domain.com

~~~~~~~~~icm/HTTP/mod_0~~~~~~~~~~~

if %{HTTP_HOST} RegIMatch "MyHostName.com*" [and]
if %{PATH} RegIMatch "^/ZP1*"
SetHeader x-sap-webdisp-target-sid ZP1
RegRewriteUrl ^/ZP1(.*) /sap$1

if %{HTTP_HOST} RegIMatch "MyHostName.com*" [and]
if %{PATH} RegIMatch "^/EXT*"
SetHeader x-sap-webdisp-target-sid EXT

~~~~~~~~~~~~~~~IE ERROR~~~~~~~~~~~~~~~

500 Dispatching Error   Error: -26 Version: 7200 Component: HTTP_ROUTE Date/Time: Mon Apr 01 14:38:58 2013 Module: http_route.c Line: 3369 Server: SAPWendispatcher_WP1_00 Error Tag: {000001e2} Detail: no valid destination server available for '!ALL' rc=13

© 2001-2009, SAP AG

[Former Member · Accepted solution]

Does it work if you define the external site as http instead of https? If it does see SAP note 1542001.

https://service.sap.com/sap/support/notes/1542001

If it doesn't, can you send the trace file as an attachment, not embedded in the body?

[curtis_mackenzie2 · Accepted solution]

HTTP or HTTPS for fowarding to an IIS site doesnt apear to work either way.  I've attached the dev_webdisp.

dev_webdisp.txt.zip

[Former Member · Accepted solution]

Can you change the configuration for testing purposes so that there is only the EXTSRV system defined? The trace indicates that Web Dispatcher is trying to query a system for message server information, you have to make sure it is not trying to do so for the EXTSRV system.

Also increase the trace level to 2 (or 3), repeat the test and resend the trace file. The verbose trace should also reveal which system is being queried.

To rule out programming error by SAP, can you downgrade to a lower patch level (sub 200 or even sub 100) and see if it works? In the later patch levels there have been many changes to the determination logic of the target system. You can find older releases from the kernel directory, in the SAPEXE.SARs.

[curtis_mackenzie2 · Accepted solution]

Thanks you got me on the right path. 

I backed every thing out so that i was just doing the EXTSRV redirect and it still wasnt working and it was still looking like it was trying to query a system for the message server as you said.  So i started to look at the profile parameters and identified that is/HTTP/default_root_hdl = abap was the one causing the problems.  I've removed it and the EXTSRV redirect is working now.

Thanks for the help!

Is it normal behavior when using the EXTSRV option with the SAP web dispatcher for it to push the communication over to that servers URL?  Or should it be keeping the URL of the Web dispatcher and handeling the traffic?

For instance with an SAP server if i were to go to lets say https://mysapwebdisp.com/SID/bc/ping it keeps this adress, keeps communication routed through the SAP dispatcher instead of correcting the url to https://mysaphost.domain.com/sap/bc/ping.

It seems with the EXTSRV option it will take the https://mysapwebdisp.com/website and rewrite the url to http://www.somewebsite.com and be done with the routing of the communication.

[Former Member · Accepted solution]

I have not used the EXTSRV feature but what you are describing sounds more like a URL rewriting issue.

If EXTSRV indeed only does a HTTP redirect I'm guessing that was chosen because Web Dispatcher has no way of knowing how to handle sessions, session stickiness, pooling, etc. since the accessed external web server could be anything.