Load balancing web services

[Former Member]

Our architecture has 4 app servers and a central instance. Just recently, we enabled web services. The WISDL points to a specific server depending on which server you access the WISDL.

What is the recommended approach to load balance accross the servers? Set up a load balancer switch outside of SAP or can the J2EE handle internally? Should the WISDL point to the central instance? etc.

I am having trouble finding discussions or documentation on this subject.

I will reward points. Thanks!!!1

[Former Member]

Yup point it to the central instance

Rgds

[Former Member]

Narendran....

Can you give the benefits of pointing to the central instance vs. spreading the web services accross the app servers? We are trying to provide a work around while we work to implement an actual load balancing solution.

I will award points for your answer.

[former_member181887]

Hi Stephen,

Another option if your web services are executed in the ABAP Stack is that you can do load balancing via the ICM. You can add load balancing (like logon load balancing) in transaction SICF.

Once you do this you have to call the web service by pointing at the message server (usually on the CI) and it will be redirected automatically.

I'm assuming you have setup a message server for HTTP calls which a pre-requisite for this.

BTW, Web Dispatcher is the preferred method but this works too.

Cheers,

Mike.

[Former Member]

Can you go into a little more detail. We have I believe the same setup as you just described. We have 2 app servers on 6.40 and would like to load balance between them. We have set the ms/server_port_0 = PROT=HTTP,PORT=8100. (Which for some reason rsaparam has flagged as red.) We have set parameter ms/http_port = 8100 in each of the app servers. In SICF we have activated both sap/public/icf_info/urlprefix and sap/public/icf_info/logon_groups. When we run a BW querry it runs just to the CI.

A couple of questions: 1) In the 2 SICF services there is a place for logon groups, is this a pre-requisite and if so, can a normal GUI logon group work that is just pointing to the 2 app servers? If they don't work, how do you create a logon group just for HTTP load balancing? 2) Is there some other settings that we could be missing?

Any help on this matter would greatly be appreciated as we have been struggling with this for some time.

Thanks,

Jared

[Former Member]

So it Netweaver architecture doesn't make this easier than using a third party load balancing solution.

[Former Member]

Hi Stephen,

This is not entirely accurate. The SAP Web Dispatcher integrates natively into the SAP landscape. This means that it gets its load balancing information from the dispatcher of the respective system, using SAP load balancing algothrims. With 3rd party load balancers, this is not the case. Also, the SAP Web Dispatcher is a standard part of a customer's contract, meaning there is no extra charge.

The SAP Web Dispatcher may also work with 3rd party load balancers if necessary.

Also announced at Sapphire is a partnership with Cisco to put the SAP Web Dispatcher directly on Cisco hardware, giving it the performance advantage of hardware load balancers. This solution is currently in pilot stages.

Regards,

Matt

[Former Member]

Hi Stephen,

The SAP Web Dispatcher can be used to load balance. See http://help.sap.com/saphelp_nw04/helpdata/en/42/5cfd3b0e59774ee10000000a114084/frameset.htm.

Best Regards,

Matt