SAP Logon Groups (SMLG)

[Former Member]

Hello,

I need to understand how to setup the automatic load balancing between two SAP systems (central and dialog systems). I searched for some tips in the SAP Help but I can´t find the way to setup the Load Balancing, I want to let the SAP system choose by yourself which instance is better, I mean, when users log on to the system, they are automatically logged on to the server that currently has the best performance statistics and/or the fewest users.

Logon Load Balancing - Configuration - SAP Library

Can you give me some guides... or tips?

Thank you,

samid raif

[Former Member]

Hi Samid,

If I understood your requirement properly, then below information should solve your issue.

After creating logon group, double click on it and go to Attribute tab, here you can set - Response time and Users (number of users) as a threshold to assign new login request to least loaded server.

Regards,

Ashish

[former_member182657]

Hi Samid,

I need to create only one logon group and add to this group the two instances?

Yes a common group can be used for all the instances at your end.For more details on same i would suggest you to follow SAP Note 26317 - Set up for LOGON group for autom. load balancing

& can refer Configure and use logon group (ABAP) - Basis Corner - SCN Wiki

Hope this will help you.

Regards,

[Former Member]

Hi Samid,

I think you already found the answer in the link you have mentioned in your question.

But, if you are looking for more detailed information consider the below scenario, I hoe this will help you understand Logon group configuration.

Lets say you have a SAP system ABC with 4 application servers Z1, Z2, Z3 and Z4. You can decide the servers to which the sap logins to be routed using logon groups concept. For this you can create a logon group name say END_USERS1 and add a application server to this, group. You need to repeat this till you have added all the planned application servers to this group.

So now if you add Z1, Z2 and Z4 application server to logon group END_USERS1 , message server will now decide the best app server available in the logon group to distribute the load .

Once the logon group is created on SAP you need to change the logon pad details on users' SAP GUI which should now have connection type Group/Server Selection and enter the message server name, this will allow you to pick the Group/Server from the drop down list.

I hope this information would help you understand configuration of logon groups.

Please go through the SAP link you mentioned in the question and let us know if you still have any further questions.

Regards,

Pradeep

[Former Member]

Hello Pradeep,

Thank you for your explanation

In my scenario I have two servers (one central instance and one dialog instance), so in this case how can I set the logon groups to have that automatic distribution of users between these two SAP instances? Can you give me an example?

I need to create only one logon group and add to this group the two instances?

Kind regards,

samid raif

[Former Member]

Hi Samid,

Yes, that's correct, you need to create one logon-group and assign the same to these two instances.

Start creating the logon group from transaction SMLG and you will get to know how it works

Let me know if you need more help.

Regards,

Pradeep

[Sriram2009]

Hi Samid

In this case your are having two instances (CI + DI) almost 65 to 75 % of users login into Dialog instance, balance 25 to 35% light users can be use the CI, because the CI = CI + database.

BR

SS

[mamartins]

Hi Samid,

On Netweaver 7.40, SAP recommend to separate the Central Instance (ASCS00) from Dialog Instances (DVEBMGS01 or 02 or 03...).

Usually no one connects to the CI, but to the DI. You only need a LOGON_GROUP if you have more than 1 DI running.

Regards,

M

[Former Member]

Hello Pradeep,

Ok. I already created one logon group and I added it the two instances (Central Instance and the Dialog Instance):

[Image removed by moderator]

I already set the SAP logon entry to the "Group/Server Collection":

But now how can I test the Load Balancing mechanism?! Because when I logon into the system, I always connect in the SAPWD01ERP instance (central instance)... !!

Kind regards,

samid raif

Message was edited by: Moshe Naveh

[former_member185954]

Hello Samid,

You need to simulate user load, SAP application servers are pretty robust, one dialog process in an application server can serve upto 10 users provided none of them is running a job in foreground and occupying it.

I suggest you ask few of your colleagues to attempt to login simultaneously and some of them may get distributed to other application server.

Regards,

Siddhesh

[Former Member]

Hi Samid,

Sriram has explained it very well.

Once the logon group is configured , the logon is automatically performed using the instance of the group that currently has the best dialog quality. You can check this from SMLG->GOTO->Load Balancing

The Instance with better quality will be the next best option for message server to distribute the load.

In the above screenshot the last instance has the best quality among the 4 available instances.

Please refer to the section :

Changing Properties of an Assignment, a Logon Group, or an Instance

in the below link for more details on how to change this configuration.

Configuring Logon Groups - SAP NetWeaver by Key Capability - SAP Library

Regards,

Pradeep

[former_member185954]

Hello Samid,

The link you provided has all the information, what part is not understood ?

Regards,

Siddhesh