Parallel Processing when running in background

[paul_thompson5]

Hi

We have implemented a parallel processing solution using the Call Function Starting New Task Destination in Group format to split a large number of updates across an RFC Server Group.

This works well when running the ABAP in dialog, but when we schedule for background processing, the parallel processing does not seem to occur, we get a single background process.

Does anyone have any ideas why this may be occuring ?

Thanks

Paul

[Former Member]

Paul,

Starting new task will start a new LUW in dialog process and not in background. This is the reason you are having a problem. While technically STARTING NEW TASK is used for parallel processing, you need to consider whether the program will be run in foreground or background mode.

In case of background, you need consider using multiple jobs via job open, submit, job close. This way you can initiate more than one process in your server group to do the work.

You will need to consider the # of background WP available and the # of WPs you can use for this program.

So if there are 100 WPs available and you can use only 10 at any give time, then you should schedule 10 jobs and then check the status of the 10 jobs before you can start scheduling the next jobs.

You can use the FM SPBT_INITIALIZE to check the # of WPs that are currently available in the server group.

Hope this helps.

Thanks,

Vikram.M

[paul_thompson5]

Thanks Vikram.

We have implemented as per the SAP help

http://help.sap.com/saphelp_nw70/helpdata/en/fa/096e92543b11d1898e0000e8322d00/content.htm

which seems to suggest, if the report is run in background or foreground, it will still parallel process.

Is this not correct ?

[Former Member]

Dear Paul,

Parallel processing still takes place when the main program is run in the background using the method from the sap help link. Your main program will be running in the background work process and the tasks created in your program will use dialog work processes for execution.

Regards,

Aashrith.

[Former Member]

Paul,

Did you check if you have enough dialog process available when you are scheduling the main program in the background?

Thanks,

Vikram.M

[paul_thompson5]

Thanks Aashrith, that was what I thought reading the help text.

[paul_thompson5]

Yes we do that. 

[paul_thompson5]

The mystery is solved.  It does parallel run as expected in background, but our algorithm for deciding to parallel run or in line run was wrong.

Thank you for you help.