RFC Quota

Why this blog is here?

In XI there are many way to up the performance and performance depends on so many of factor. XI uses Remote Function call (RFC) connectivity extensively so optimization of RFC setting on both sides R/3 as well as J2EE can play important role. Lets I try to describe each parameter of RFC Quota in detail.

What it mean?

Depending on existing CPU and main memory, the ABAP side of the XI server can be optimized by different different parameterizations.

 

1) rdisp/rfc_use_quotas : This parameter is used to activate the use of quotas for resource allocation. The following values are permitted:

0: resource allocation deactivated

1: resource allocation activated (default)

 

2)rdisp/rfc_max_queue : This parameter specifies the contingent for the maximum number of outstanding requests in the dialog queue. You can monitor how full the dispatcher queues are in transaction SM51.

SAP Suggestion: You should set this value quite small, as the dialog requests are also kept in this queue, and it is important that the queue does not become full.

 

2) rdisp/rfc_max_login : This parameter describes the contingent for the number of RFC users logged on to the SAP system.With transaction SM04 you can see users list.

 

3) rdisp/rfc_max_own_login : With this parameter you can set the cut-off value for the number of own logons in the SAP system. It is different from the parameter “rdisp/rfc_max_login” in that in this case, it is the logons of one user only that may not exceed the quota. This parameter is valid only if the check is run locally

 

4) rdisp/rfc_max_own_used_wp:This parameter determines the contingent of dialog work processes that an RFC user may occupy simultaneously. The value is specified as a percentage of the configured dialog work processes.

 

5) rdisp/rfc_min_wait_dia_wp :This parameter is used to reserve a number of dialog work processes for dialog mode. It specifies the number of dialog work processes that should be kept free for dialog mode, thereby preventing that all processes are occupied by parallel RFCs.

SAP Suggestion: If a sufficient number of dialog work processes have been configured, this value should be increased. It must be guaranteed that the value of parameter  rdisp/rfc_min_wait_dia_wp is always smaller than rdisp/wp_no_dia, otherwise no RFC requests can be processed.

 

6) rdisp/rfc_max_comm_entries:The value specifies the percentage of communication entries that may be occupied by the user.

 

7) rdisp/rfc_max_wait_time;This parameter determines the maximum period of time in seconds that the system waits after a load check. The wait time is calculated based on the amount of available resources. The fewer resources that are available, the longer the wait time.

For getting RFC Quota transaction RZ12 :

 

You can set the maximum resources for RFC users as follows.

rdisp/rfc_max_login        = 100

rdisp/rfc_max_own_login    = 100

rdisp/rfc_max_own_used_wp  = 100

rdisp/rfc_max_comm_entries = 100

For example, number of work processes which are present in R/3 basis stack for processing the queues and we know that J2EE stack logs on the R/3 basis stack per RFC dialog user. Hence no need to increase the number of batch process need to control dialog process and for that we had parameter “rdisp/wp_no_dia”.

Also , Maximum value for the Max no of Wps used depending on the work process. We should consider every work process Number of available work process can be set with transaction RZ04.For any change in profile parameter restart is required.

For check more parameters to do with RFC, Go with transaction RZ11 :

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TIPS :

Points when configuring the system:

• The number of available resources in the system is a snapshot relating to the current workload in the system. No program can assume that these resources will also be available long term.

• If one of the quotas is exceeded, no resources are returned to the caller.

• The calculated resources are not reserved for the caller. Thus it could happen that competing programs are calculating resources at the same time, and are occupying more dialog work processes than has been set in the quota.  A program therefore cannot assume that the resources calculated are actually also available.

https://help.sap.com/saphelp_nw04s/helpdata/en/fd/1d75a8f34308449ef6c4cdcda4e137/content.htm

Want to digest more?

Here these blog which really impressed a lot to me.

When you talk about performance these two blog  impressed me lot from Prasad Illapani :

Performance Tuning Checks in SAP Exchange Infrastructure

 

Performance Tuning Checks in SAP Exchange Infrastructure(XI): Part-II

 Transaction SARFC :Monitoring RFC Resources on the Application Server

 Reference:

SAP ONLINE DOCUMENT.

Books:

Mastering SAP XI-Administration by Marcus and H Klein.

What next :

Tunning Gateway and communication parameters.