EHP7 SGEN in Shadow System

[Former Member]

Hi Experts,

We are upgrading our ECC EHP6 system to EHP7 using nzdt option. We are using SUM patch 13. We are using SGEN mode:

Generate ABAP loads on shadow system during uptime & start asynchronously in Post downtime

SUM provides an option where we can decide how many  processes we want to use for SGEN. Can you please confirm what is the maximum amount of SGEN Processes which we can use & is it dependent on any of values like ABAP Processes (Uptime/downtime) , SQL Processes(Uptime/downtime), R3trans Proceses(Uptime/downtime), R3load Processes(Uptime/downtime), Parallel Phase(Uptime/downtime)?

So for example can we use 8-10 SGEN processes. if yes what do we need to do ?

Regards,

Ajay Sehgal

[james_wong]

Hello Ajay Sehgal,

I would suggest you follow take a look at KBA 1616401 - Understanding parallelism during the Upgrades, EhPs and Support Packages implementations.

This KBA talked about setting up parallel processes dramatically increase the
performance of Upgrades and Updates in SAP systems.

It is also feature in Upgrade Troubleshooting Guide site: List of Feature SAP Notes - Technology Troubleshooting Guide - SCN Wiki

Best regards,

James Wong

[Former Member]

Hello Ajay,

Please check the following SAP note:-

1674812 - Performance improvement for ACT_UPG

This note talks about (Point 5)Phase ACT_UPG but the number of dialog work process defined in the shadow instance profile will continue to remain till completion of upgrade.

so consider increasing dialog work process as suggested.

I hope this helps you in addressing the issue.

Regards

Anand

[Former Member]

Hi Anand,

The note you mentioned yeah tells how to increase the work processes in shadow instance but this means you will need to fail your running SUM which is stopping & start shadow instance:

Is there any way when we select the advance mode for nzdt we can specify something . There are many parameters on that screen :

ABAP Processes (Uptime/downtime) , SQL Processes(Uptime/downtime), R3trans Proceses(Uptime/downtime), R3load Processes(Uptime/downtime), Parallel Phase(Uptime/downtime)

Regards,

Ajay

[Former Member]

Hello Ajay,

As you said, you have seen that screen right which asks for ABAP Processes (Uptime/downtime) , SQL Processes(Uptime/downtime), R3trans Proceses(Uptime/downtime), R3load Processes(Uptime/downtime), Parallel Phase(Uptime/downtime) and all..?

Please confirm.

Regards,

KK

[Former Member]

Hello Ajay,

Please refer following SAP link,

It talks about option in advanced mode(Even though its in nZDM its related to nZDT)

You will get a fair idea.

Regards

Anand

[Former Member]

Hi KK,

yeah i have seen the screen but what parameter in this screen decides what will be total number of work processes in shadow system.

Warm Regards,

Ajay

[Former Member]

Ajay,

You can stop running SUM as earlier told by you and can continue from the same phase after work process are increased.

Regards

Anand

[Former Member]

In the same screen if you scroll down i mean if you go down... There you can see whether shadow system needs to be on remote system or the system... And processes for SGEN it will ask there.. There we can give the processes what ever we need.

Have you gone through this?

Regards,

KK

[ashish013]

Hi Ajay,

There is no fix value for SGEN. It depends upon on resources your system like memory and cpu. you need to test it once in Dev. Upgrade and then accordingly you can select for your production.

Also check the  http://scn.sap.com/docs/DOC-45291 for SGEN

Thanks & Regards,

Ashish

[Former Member]

Hi Ashish,

Let me put it another way.

1) SGEN is to be running in Shadow

2) I understand i dpenedes on CPU & Memory.

But SGEN uses the dialog procesess on shadown system so obviously it needs to have number of processes to run which we are defining for sgen, so for example 8 for SGEN.

So shadow system needs to have that many free processes available to run it. So which parameter defines that how many work processes will be in shadow system.

Regards,

Ajay Sehgal

[Former Member]

Hello Ajay,

Yes SUM provides that facility to provide number of parallel processes for running SGEN also post upgrade.

For this you can give the 90% of the value of your dialog work processes present in your system.

Suppose if you have 20 dialog work processes then you can give 18...

To give the same.. where ever it asks processes for ABAP processes and SQL... scroll down there.. you will get option for SGEN also.

Please check the same and confirm.

Regards,

Karthik

[Former Member]

Hi Karthik,

Thanks for your response. SGEN is run in shadow system in which it starts the background job which then submits the dialog sessions in shadow system only. As far as i know shadow instance runs with certain work processes. So how is SGEN then dependent on total number of work processes in real system.

Also we are running the SGEN in uptime & not post upgrade.

Regards

Ajay

[Former Member]

Hello Ajay,

I thought SGEN is running in real system so i told about work processes in real system..

If it is running in shadow system also... you would have given the number of work processes at inputs time only.. what ever the work processes are there in real system .. the same will be there in shadow system also...\

So based on that you can decide parallel processes.

If already inputs phase is passed and SGEN already started you can not do the same.

[Former Member]

HI karthik,

I dont think that answer my questions.

On What is total number of SGEN processes depend on.

Regards,

Ajay Sehgal

[Former Member]

Based on the work processes present in your shadow or real system and your input which you have given for your upgrade.

Regards,

Karthik