Multiple Dispatcher in The Landscape

[Former Member]

Hello Folks,

We are using web dispatcher for our ECC systems. Now we are planning to extend this to our other systems in the land scape llike EP, BI, BO etc..

Request you to share your thoughts planning the web dispatcher in the landscape and following concerns

Scenarios:

A. Multiple systems in a single web dispatcher

B. Indepedent web dispatchers for each landscape.

and

C. if we can go with option B how it would be feasible to put multiple web dispatchers in a single host equipped with high CPU and memory.

Waiting for your response

Thanks in advance

Satyabrat

[Former Member · Accepted solution]

Hi,

One Web Dispatcher CAN handle several systems but this is, however, more complicated.

One Server can host several Web Dispatchers but I wouldn't recommend a single server for all Web Dispatchers due to reasons of "Single Point of Failure" (If the server crashes, ALL Web Dispatchers are down).

The middle road would be to have e g three servers: Dev, Test and Prod.

On each of these you can install all the Web Dispatchers you need for your respective landscape.

In this scenario single point of failure still exists, but it might be enough for your organization.

So by the end of the day, it is a matter of your service level agreements and security demands.

[Former Member · Accepted solution]

Hi Thomas/Sriram,

Why we are planning in the single server is, to reduce hardware cost & maintenance. We want a  dedicated server for all WDs and will put in a HA environment.

So my question is if we put all the WDs on a single host, what are the things that need to be taken into considertaion.

Thanks & Regrds,

Satyabrat

[Sriram2009 · Accepted solution]

Hi

In which OS ?

Kindly refer the installation guide (require SAP S-user id)

https://websmp204.sap-ag.de/~sapidb/011000358700000877232012E

BR

SS

[Former Member · Accepted solution]

I simply can not recommend a single server solution, even if it's a HA environment.
The different Web Dispatchers can be patched separately so that is not the problem.

The problem lies in the life cycle of the solution.
I would never want to be in the situation where I need to perform a certain maintenance, work for the first time ever, in a production environment.

The absolute minimum (in my personal opinion) in your case would be a two-server scenario in that case. One for Dev/Test and one for production.

One Consideration in your case is how the HA-environment can handle the Web Dispatchers.
I haven't seen any specific documentation about Web Dispatcher and HA environment.

it seems to be primary built for local installations on a single server.

I'm sure that you can tweak the installation to work in HA but the Web Dispatchers will, in this case, not be spread evenly between the HA-nodes since all Web Dispatchers will be dependent on the common share "sapmnt" (in windows environment) and thus end up on the same node.

[Former Member · Accepted solution]

Hi Tomas/Sriram,

The OS is windows 2008R2 & 2012 server.

Yes..It would be really make a senese that We can put Two WD, One for all TEST and DEV env and One for Prod  environment.

So if I will put all Prod systems (ECC, EP, PI, BI, BO) in one WD, what are the things I need to be take care and what are the area that need special attention according to you.

Thanks & Regards,

Satyabrat

[Former Member · Accepted solution]

Hi,

I'm sorry if I'm not clear enough. What I was talking about was two servers.

I would recommend one WD per system (much more complicated with one WD for all SAP systems instead of a one-to-one relationship).

Since ABAP and JAVA are using complete different url-paths in the system, it's quite easy to make one WD to handle ERP (ABAP-only) and EP (JAVA only).

That would take down the number of WD's needed but then you have two different kind of installations (some one-to-one and some one-to-two) to maintain.

These kind of differences tend to be expensive in the long run so that's is the reason why I don't recommend it.

I do not see a big problem with maintenance of several WD's since WD is a part of the Kernel (and therefore easy to patch).

[Former Member · Accepted solution]

Hi Tomas / Sriram,

Thanks for your help ful inputs. Further more queries from my end...

1. What will be challenges, if we put multiple ABAP stack on one WD or Multiple Java stack on one WD.

Like in the scenario where we have to put DEV and QA in same WD

2. If you can share some inputs on sizing that would be realy helpful. I have gone through the sizing guide, but not completely sure abt the hardware requriment.

We have 1200 users including 500 ESS/MSS users.

Thanks & Regards,

Satyabrat

[Sriram2009 · Accepted solution]

Hi

Refer the SAP links

Configuring SAP Web Dispatcher for a Large Number of Users - SAP Web Dispatcher - SAP Library

https://websmp107.sap-ag.de/~sapidb/011000358700000877232012E

BR

SS

[Former Member · Accepted solution]

1. What will be challenges, if we put multiple ABAP stack on one WD or Multiple Java stack on one WD.

Like in the scenario where we have to put DEV and QA in same WD

It is still complicated to have one single WD for many systems so I will assume that you have one server wd001.comp.com where you want to install serveral WD's WD1, WD2 and WD3.

In this scenario you have two different choices (in my opinion):

1 - Same hostname, different ports
You have to configure each WD to listen to a unique port

WD1 - listening on port 8080

WD2 - listening on port 8081

WD3 - listening on port 8082

Then they are called accordingly:

http://wd001.comp.com:8080/...

http://wd001.comp.com:8081/...

http://wd001.comp.com:8082/...

2 - Unique hostnames, same port.

You configure several ip-adresses for the same host and give each a unique name.

WD1 - wd1.comp.com

WD2 - wd2.comp.com

WD3 - wd3.comp.com

Then you configure each WD to listen for it's own unique ip-adress and they are called accordingly:

http://wd1.comp.com/...
http://wd2.comp.com/...

http://wd3.comp.com/.. 

[Former Member · Accepted solution]

Hi Tomas,

I want to setup same hostname with different port as now we are planning to use only one WD for all SAP systems.

can you please guide me what shoudl be the parameter need to be maintained in the profile parameter.

Please refer below parameters in my profile parameter.

****************************************************************************************

# Accesssability of Message Server

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

rdisp/mshost = ECC HOST

ms/http_port = 8100

ms/https_port = 8443

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

rdisp/mshost = Portal HOST

ms/http_port = 8101

ms/https_port = 8443

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

# 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=6666

#icm/server_port_1 = PROT=HTTP,HOST=localhost,PORT=81$$

icm/HTTP/admin_0 = PREFIX=/sap/admin,DOCROOT=$(DIR_DATA)$(DIR_SEP)icmandir,AUTHFILE=$(icm/authfile),PORT=81$$

icm/server_port_1 = PROT=HTTP,PORT=7777,TIMEOUT=900,PROCTIMEOUT=900

icm/server_port_2 = PROT=HTTPS,PORT=8443,TIMEOUT=900,PROCTIMEOUT=900

icm/keep_alive_timeout = 900

icm/host_name_full = <Hostname webdisptacher>.abc.com

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

# Start webdispatcher

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

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

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

SETENV_01 = SECUDIR=$(DIR_INSTANCE)/sec

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

# Parameters for the SAP Cryptographic Library

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

ssl/ssl_lib = E:\usr\sap\QWT\W01\sec\sapcrypto.dll

ssl/server_pse = E:\usr\sap\QWT\W01\sec\SAPSSLS.

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

********************************************************************************************************

Thanks & Regards,

Satyabrat

[Former Member · Accepted solution]

Hi,
This is a solution which I can not recommend to you.
One single WD is too much of a SPOF so I have never tested that kind of configuration so this is as far as I can help you in this specific case.

For example, the following parameters can only be entered ONCE in the profile:

rdisp/mshost

ms/http_port

ms/https_port

Instead, you're bound to use redirect (The redirect is not needed if you install several WD's since you then decide which target system to connect to with the above parameters only)..

I'm not sure but I suspect that the WD simply gives you a new url to the target server and port (which is internal host name and not known to the internet (DMZ).

You have to test the parameters for yourself to find out if it works correctly.

You have to define one icm/server_port_<n> for each port you want to listen to
(like you have done in the instance profile).

Then you need to specify one redirect for each server to redirect to (I'm guessing here).

icm/HTTP/redirect_0 = PREFIX=/, FOR=*:6666, TO=/, HOST=<target host>, PORT=<target port>

icm/HTTP/redirect_1 = PREFIX=/, FOR=*:7777, TO=/, HOST=<target_host>, PORT=<target_port>

icm/HTTP/redirect_2 = PREFIX=/, FOR=*:8443, TO=/, HOST=<target_host>, PORT=<target_port>

/ Tomas

[Former Member · Accepted solution]

Hi Tomas,

Lets make it simple. I have installed one WD and I want to use this only for my portal system.

Now the scenario is of 1 to 1

Can you recommend what should be the parameter need to be maintained. The above parameter profile is not working for me.

BR,

Satyabrat

[Former Member · Accepted solution]

Remove the entries for the ERP-host (rdisp/mshost, ms/http_port, ms/https_port).

Decide how you would like to communicate:

1 - Do you want to access WD via http or https
2 - Do you want to access Portal via http or https

icm/server_port_0 should be how you access the WD.

icm/server_port_1 should point to the portal with the correct protcol and port.

remove icm/server_port_2

E g start simple with just HTTP:

icm/server_port_0 = prot=HTTP, PORT=80, HOST=<hostname>.abc.com, VCLIENT=0

icm/server_port_1 = prot=HTTP, PORT=8101, VHOSTIDX=0

if you access the WD with http://<hostname>.abc.com the calls will be re-routed to port 8101 at the portal.

If this works, you can change to WD to use HTTPS and truncate the encryption at WD before the re-route to the portal. Just changing this one line will change that behaviour:

icm/server_port_0 = prot=HTTPS, PORT=443, HOST=<hotname>.abc.com, VCLIENT=0

Note that you need to have your certificates created and imported in order to make it work!

Start simple and then add complexity step by step..

[Former Member · Accepted solution]

Hi Tomas,

Thanks for your valuable inputs. I have also activated https in the server and also set the profile parameter to activate my portal and ecc systems in a single dispatcher. Now things are going smooth.

It was the error with the kernel due to which my Java stacks are not at all recognized by the webdispatcher. Soon the kernel is upgraded its started working.

BR,

Satyabrat

[Former Member · Accepted solution]

Great 😄

[Sriram2009]

Hi Satyabrat

A. Multiple systems in a single web dispatcher

Refer the link  https://help.sap.com/saphelp_nwce72/helpdata/en/c5/ec466f5544409982c7d3ca29ce1ad3/content.htm

SAP Web Dispatcher for Multiple Systems - SAP Web Dispatcher - SAP Library

B. Indepedent web dispatchers for each landscape.

Importing the SAP Web Dispatcher - SAP Web Dispatcher - SAP Library

SAP Web Dispatcher - SAP Library

C. if we can go with option B how it would be feasible to put multiple web dispatchers in a single host equipped with high CPU and memory.

http://scn.sap.com/thread/534817

Memory Requirement of the SAP Web Dispatcher - SAP Web Dispatcher - SAP Library

http://www.sdn.sap.com/irj/scn/go/portal/prtroot/docs/library/uuid/20951016-604e-2a10-2e82-9950bfe0a...

BR

SS

[Former Member]

Hi Sriram,

I have checked the links...but still it not answered my all question.

If I plan to install all web dispatcher (WD for ECC, EP, PI, BI etc) on a single host,  what would be the pros and cons and how it can be achieved.

and how it will be different If I would go for indepedent WD in indepedent hosts (e.g. WD for in ECC one host, EP for one host etc..)

Let me explain...

Scenario :

All ECC systems in WD - EWD

ALL EP system in  WD - PWD

ALL BI systems in WD - BWD

In above scenario I have multiple system  on each WD.  Whether this can be achived.

further if I will go ahead with one more step

Now I want put all the above WDs (EWD, PWD, BWD..) in one single host ...

Whether this is feasible ?

Thanks & Regards,

Satyabrat

[Sriram2009]

Hi Satyabrat

1. Scenario :

All ECC systems in WD - EWD     
ALL EP system in  WD - PWD
ALL BI systems in WD - BWD

1. You can install the web dispatcher for ECC,EP & BI one independent host or

       WD - for ECC - EWD on any one the ECC host

       WD - for EP - PWD on any one the EP host

       WD - for BI - BWD on any one the BI host

.

 In above scenario I have multiple system  on each WD.  Whether this can be achived.

further if I will go ahead with one more step

Now I want put all the above WDs (EWD, PWD, BWD..) in one single host ...

Whether this is feasible ?

For this you can have Cluster environment for single point failure either Windows Failover cluster  or Linux/Unix cluster

BR

SS

[Former Member]

H Sriram,

Can I put all the above WDs (EWD, PWD, BWD..) which contain their repective systems in one single host ??

Thank & Regards,

Satyabrat

[Sriram2009]

Hi

Yes, You can use one single host.

BR

SS