qRFC tips & tricks

This blog will give tips and trick on the basis part of qRFC (queued RFC).

Questions that will be answered are:

  • How to assign a specific server group to qRFC?
  • How to correct host ID in SMQS?
  • What to do with the scheduler error RES_LACK?
  • What to do when inbound entries in SMQ2 stay in status RETRY?

Assigning specific server group for qRFC

In RZ12 you have defined a specific server group. In SMQR or SMQS you can assign that server group with menu option Edit / Change AS group:

How to correct host ID in SMQS?

After a system copy the host ID in SMQS might be still pointing to the old system. To solve this, goto SM51 and select menu option Goto / Host Name Buffer / Reset / Entire System. Then go back to SMQS and re-activate the scheduler via menu option Edit / Activate Scheduler. See also OSS note 2377064 – How to correct the host ID in SMQS.

Outbound scheduler in status RES_LACK

If the outbound scheduler SQMS has the status RES_LACK, then the amount of DIA versus BTC processes is not balanced. Follow the instructions from OSS note 1970757 – Outbound qRFC scheduler with status RES_LACK to balance the processes.

Deletion of queued messages

Deletion of queued messages is possible, but should be done with care. After deletion, support can be lost on certain functions. See for example OSS note 2375304 – Deleted queues from SMQ2. You can apply OSS note 2837536 – Customer Connection – Improvement Request 217719 – Authorization check for message deletion in Smq2 / Smq3 to restrict the access to message deletion via special authorization object.

Inbound queues SMQ2 stay in status RETRY

When inbound entries in SMQ2 queue remain in status RETRY, this is normally caused by lack of authorization for launching batch job. This can happen to background user and user reprocessing the jobs. Check the authorization trace to see what needs to be fixed. More background in OSS note 1862256 – Inbound queues (SMQ2) stay in status RETRY.

Queue resets via batch jobs

Report RSQOWKEX can be used to reset the outbound queue. RSQIWKEX can be used to reset the inbound queue. The goal is to reprocess messages in error state like SYSFAIL, CPIERR. More details are in OSS note 2552322 – RSQOWKEX and RSQIWKEX. Note 2195856 – Double message execution explains to be careful with using these programs with status RETRY.

These programs can be scheduled in batch mode to automate reprocessing.

SWLT performance tuning worklist

This blog explains how to use the SWLT performance tuning worklist to find poorly performing Z code by combining SQL monitoring data from production and ATC results.

Questions that will be answered are:

  • How to setup the SWLT performance tuning worklist tool?
  • How to analyze the results from the SWLT performance tuning worklist tool?

Preparations

As preparation for the SWLT tool you must have run the SQL monitor in a productive system and created a snapshot of the data. This snapshot you can export and import in a development system. In the development system you configure and run the ATC code check tool.

The SWLT performance tuning worklist tool will combine these results. As example we will use this poorly written Z code:

Running the SWLT tool

Start transaction SWLT:

You can reduce the scope by just taking the needed Z packages. Goto the tab Static Checks to select the appropriate result of the ATC run:

Now select the SQL monitor tab to select your SQLM data snapshot you took from your productive system:

Now that all data is loaded, you can hit the execute button to start the SQL performance tuning worklist.

The tool will now start to merge the results. In the example above you can see the following result:

In the total result select a line. On the bottom left you can see the SQL monitor results. Bottom right you can see the ATC check result. Clicking on the underlined program or SQL statement will bring you to the poorly performing ABAP code point.

SQLM SQL monitor

This blog will explain about the SQLM tool to monitor expensive SQL statements in a productive environment.

Questions that will be answered are:

  • How to start and configure the SQLM tool?
  • How to analyze the results?

Configuration of SQLM tool

The SQLM tool does not require specific configuration or installation if you have a bit modern SAP system. To activate it start transaction SQLM and click on the Activate button for All Servers:

The trace is active now until the given time frame.

Example use of the SQLM transaction

First we start by writing a very bad performing Z program:

This program is really inefficient. After activation of the SQLM monitoring we run this program a few times.

Now we goto the SQLMD transaction (or from SQLM and then press display data button) to display the SQL monitoring results:

Selection can be done on total number of executions, execution time, amount of records. Result:

You see now the impact of our badly written program. Double click on the line will jump to the ABAP code point.

Creating snapshots

At the bottom of the SQLM start screen there are the buttons to create snapshots:

This results into the Snapshot screen:

You can create a snapshot here for later re-use. You can also download the snapshot to a different system by using these buttons: first export to file:

When you have the file, goto the target system and start SQLM and press create snapshot. Now use the option Create with Data Source File Import.

This is quite common practice to capture data in production by a basis administrator, who exports it, and hands it over to an ABAP developer using the data as upload in SQLM in the development system to improve poorly performing Z code.

Background information

More background information can be found in OSS note 1885926 – ABAP SQL monitor.

Useful blog (which is start of blog series on SQLM): link.