Ehp R3trans choice

[benoit-schmid]

Hello,

If we increase the number or R3toad processes for EhP application, it increases parallelism.

Therefore phases like TABIM_TRANS consume less time.

But increasing this number of processes also implies more "ORA-00060: Deadlock detected".

These deadlocks consume time.

Therefore I am interested by setting this parameter correctly by selecting the best compromise.

1. Which typical value do you set for this parameter?

2. Is there a way to find the optimal value?

Thanks in advance for your answers.

[JPReyes · Accepted solution]

R3toad

Is that a hybrid of R3trans and R3load?

In any case I think the best value for R3load is 2 per CPU core.

Now, you should not find issue with deadlocks during exports or imports, what are your concerns?

Regards, Juan

[benoit-schmid · Accepted solution]

Hello Juan,

Juan Reyes wrote:

Is that a hybrid of R3trans and R3load? 

In any case I think the best value for R3load is 2 per CPU core.

Now, you should not find issue with deadlocks during exports or imports, what are your concerns?

The non hybrid is R3trans as specified in the tittle.

Sorry for the typo 🙂

You are saying that there is no deadlock issue, but have a look at your Oracle database alert log,

during a TABIM_TRANS phase.

Then you will notice that there are always deadlocks if parallelism is configured.

Regards,

[JPReyes · Accepted solution]

I think you already have the same conversation early in the year

[benoit-schmid · Accepted solution]

Hello Juan,

Juan Reyes wrote:

I think you already have the same conversation early in the year 
Avoid ORA-00060: Deadlock during SPAM update

Last year, I asked if I could tune the DB to avoid these deadlocks.

This year, my question is different.

I am asking for recommendations for setting R3trans process number.

DB tuning and R3 upgrade settings are different even if they are related.

Do you agree that it is different? 🙂

Anyway, up to now I have not got the answer.

A first answer would be to tell me what you do set when you upgrade.

Regards,

[JPReyes · Accepted solution]

Well, have you read?

1127194 - R3trans import with parallel processes

In my experience I try to keep R3trans ratio of 1:1 with the number of CPU's.

Regards, Juan

[benoit-schmid · Accepted solution]

Hello,

Juan Reyes wrote:

Well, have you read?
1127194 - R3trans import with parallel processes

In my experience I try to keep R3trans ratio of 1:1 with the number of CPU's.

This Note specify:

"Therefore SAP is not able to suggest the ideal value for 'n'. Instead, SAP recommend to start importing with "parallel=2", and to increase this number by and by until the performance gains stagnate."

How did you end up to the 1:1 ratio?

Regards,

[JPReyes · Accepted solution]

Instead, SAP recommend to start importing with "parallel=2"

That been said SAP does not tell you how many CPU's the scenario has or how is the DB  setup.

Going for a 1:1 ratio is a safe bet and a thumb rule I used over the years, the same way experience told me that for R3load a 2:1 ratio is good. No rules written about it. You can use your best judgement and even use trial and error to find the perfect tuning for you own scenario, as mentioned in the note you'll find a point were too many processes in parallel does not improve the performance.

Regards, Juan

[benoit-schmid · Accepted solution]

Hello,

Juan Reyes wrote:

Going for a 1:1 ratio is a safe bet and a thumb rule I used over the years, the same way experience told me that for R3load a 2:1 ratio is good. 

I have had worse performances by setting a ratio 3:1.

Have you also seen worse performance or stable performances when setting this to a high value?

Thanks in advance for your answers.

[JPReyes · Accepted solution]

Again its all about resources, Usually the performance will increase until the gains stagnate. Basically you want the system to use as much resources as possible without causing congestion.

Regards, Juan

[Former Member]

I had deadlock issues on SBX and DEV upgrades. Not in QA and PRD. So having a well tuned DB with enough memory means you can safely increase the parallel processes to a max of 2per CPU

Message was edited by: Juan Reyes

[Former Member]

Hi Benoit Schmid,

Refer the below kba  as it will be useful to you :

1616401 - Understanding parallelism during the Upgrades, EhPs and Support Packages implementations

Regards

Ram

[benoit-schmid]

Hello,

The note is not useful.

It explains what parallelism is.

But it does not provide advises for configuring the number of R3trans processes.

1616401 - Understanding parallelism during the Upgrades, EhPs and Support Packages implementations

[Former Member]

Hi Benoit,

Check the below one :

1127194 - R3trans import with parallel processes

1223360 - Composite SAP Note: Performance optimization during import

Regards

Ram