Additional Application server for JAVA only system

[Former Member]

Hi all,

Like in case of ABAP stack we can install multiple additional application(DI) server for load balancing.

Similary for pure JAVA stack can we install multiple additonal java application server and thnn install Web dispatcher on one system which in turn will choose any of the application server to connect to primary server(java stack).

Can anyone tell me ...am I going correct or is ther anything else for JAVA stack load balancing.

I want ppl to just log-in on webdispatcher and rest it will tak care like through which application server it will connect to java stack.

Apart from above is it possible to create log-on grp in java only system so tht perticular grp of user should log-on thru perticular application server only.

Thanks

[Former Member]

Hello,

you surely can install more java application servers just like ABAP dialog instances. And the load balancer is Web Dispatcher, it is a free product delivered by SAP, I am not sure whether there are any third party software balancers, but actually Web Dispatcher is good enough, easy to use and administer.

The web dispatcher gets load information from Java central services instance (message service) to decide which application server to forward. for example. the port for web dispatcher is 8008, and there are two application servers within your java stack, one ICM port is 8005 and another is 8007, you only need to type the address http://192.168.xx.xx:8008 in the internet brower, from this entry point, the dispatcher decides which ICM port (8005 or 8007) it should forward to be processed.

For details, you can refer to SAP material ADM200 or help portal:

[url]http://help.sap.com/saphelp_nw70ehp2/helpdata/en/48/bc1059a70a0611e10000000a42189b/frameset.htm[url]

Hope it will be helpful.

Thanks and best regards,

Nick

[Former Member]

Hi,

thats means if main portal is running on 192.168.0.1

one java application server running on 192.168.0.2 with ICM port 8005

second application server running on 192.168.0.3 with ICM port 8006

and web dispatcher running on 192.168.0.4 on port 8008

Now we need to type url: http://192.168.0.4:8008 and from here web dispatcher will decide which application servr (192.168.0.2 ot 192.168.0.3) to use to connect to main portal(192.168.0.1)

Is that correct ???

Now can I use log-on grp where perticular users can be directed to log-on using only one application server(192.168.0.2)

Regards

[Former Member]

You can run the webdispatcher on any of these systems. You don't need a separate host for this.

For webdispatcher load balancing, check the following link: http://help.sap.com/saphelp_nw70ehp1/helpdata/en/05/d5ca3d695f2051e10000000a114084/frameset.htm

Kind regards,

Mark

[Former Member]

Hi,

Wht will happen if the web dispatcher goes down..

cause thts the single pt of access fr the portal.

DO i need to install multiple web dispatcher ???

[Former Member]

Hi basis,

It seems that there is no auto fail-over mechanism within SAP Web dispatcher, but strangely, my WEB dispatcher never behave strangely, maybe there are auto-restart function hard coded in the kernel? I am not sure....

Normally, only one web dispatcher is enough, because this is the only entry point, it is useless to construct more. But if you are worried about the shutdown of dispatcher, you can try to establish more backup dispatchers with different port number, for example 8008, 8009, 8010, if 8008 failed, you just inform your users to visit through 8009 and meanwhile take actions to recover the 8008 dispatcher. this is just a suggestion , to be honest, I have never tried before.

Thanks and best regards,

Nick

[Former Member]

Hi,

If your system is critical and is HA, you need to have an High Availability Web Dispatcher.

One good solution is to clusterise it.

We did it on an R/3 system running on Windows MSCS. The Web dispatcher was added a an other cluster ressource in the SAP CI group.

Regards,

Olivier

[Former Member]

Hi Oliver,

Can you giv lil idea or any URL wher I can find info abt how to clusterrise Web Dispatcher ...

Is there any way I can direct perticular users to log-in thru perticular application server ??/

Regards n Thanks