remove a app server from web dispatcher load balancing

[Former Member]

Hi,

We have webdispatcher to process http requests in the PI system which has 6 app servers. If one of the app servers is down, how to remove it from http load balancing so that requests dont go to that app server?

Thanks & Regards,

Saravanan

[former_member789676]

I have some problems with list of active servers in SAP WEB Dispatcher. Currently one of them are shutdown but dispatcher are sending HTTP requests for him. When i check list of active servers - there is only one active J2EE server. SAP WEB Disp version 7.77.0.

[ChrisRae]

Hi Vinogradov.

I notice that this appears to be your first question asked. You may find a bit more help with your issue by asking a new question. The last comment on this question was from 2012.

If you could give us some more details about the problem and the environment, I am sure that someone will jump in and help you.

Chris

[Benny]

This happens automatically as you can see in the manuals:

The load balancer periodically fetches a list of all active application servers of an SAP system from its message server via HTTP. This list includes the host names as well as a static value indicating the capacity of each server (see below). This capacity is separated by stacks, i.e. a dual-stack instance has an ABAP capacity and a Java capacity.
When an instance is shutting down or scheduled for shutdown, the capacity of the instance will be set to 0. This means that stateful requests for existing sessions can still be sent to this instance but the instance should be taken out of load balancing, because it will not accept any new logons.
Servers will be dynamically added and removed from the list whenever the SAP message server detects a new server starting up or a running server shutting down (or crashing), respectively.
It is required that a load-balancing device removes crashed servers from its internal server list immediately for the following reasons:
The message server may take up to ten minutes to detect a server crash. Therefore, the server list may not reflect the current state of the servers
The load balancer should only update the list periodically (e.g. every several minutes)

This also needs some time to recognize it, but surely faster than you doing it manually. You can check with any browser connecting to your message server with a string like this:http://ld8060:8081/msgserver/text/logon?version=1.2

Out of four answers nobody ever read the manuals.  Including the issuer of this question five people do not know how basic network actions work on your systems. Are you really responsible for running SAP systems?

Regards,

Benny

[Former Member]

My bad, I didn't properly read the post since I missed the part that the application server is being shutdown. Of course the application server will be removed from the LB list when it's shutdown.

[Former Member]

Can be achieved by maintaining the logon group(s) for AS JAVA and AS ABAP. See the attached link.

http://help.sap.com/saphelp_nw70ehp1/helpdata/en/48/99c3d999273987e10000000a421937/frameset.htm

[mercedes_fernandez]

Hello Saravanan,

you could deactivate it manually via the Web Admin tool for the SAP Webdispatcher.

hope it helps,

Mercedes

[Former Member]

Hi Mercedes,

Where exactly do i need to deactivate in the Web admin tool. I could see below options

SAP Web Dispatcher Menu

Core System 

    Monitor 

    Active Services 

    Active Connections 

    Trace 

    Parameters 

    Hostname Buffer 

    Release Information 

    Statistic 

    MPI Status 

    ICM Security Log 

HTTP Handler 

    Access Log 

    Server Cache 

    Access Handler 

    Admin Handler 

Dispatching Module 

    Monitor Server Groups 

    SSL End To End Dispatching 

    URL Mapping 

    URL Filter 

    Parameters 

    Session Dispatching