Find out which reports caused a full extended memory

[benoit-schmid]

Hello,

This morning ST02 says EM used yesterday has reached the maximum available size.

It is uncommon on our site.

I would like to find out which report or combination of reports execution has cause the

em to be full.

1. SM21 does not show any error as far as em is concerned.

Shouldn't sm21 show an errror when em is full?

2. ST22 only show one dump but it is related to file not found, not to a memory problem.

Shouldn't we have a dump for each process that could not allocate new memory in em?

3. ST03/STAD do not show any process that have reached a value close to em.

Would you know how we could reached the max if all processes use much less?

4. How do you find em problems sources when you notice them?

Thanks in advance for your answer.

[Reagan · Accepted solution]

Good Day

Here are the answers.

1. SM21 does not show any error as far as em is concerned.
Shouldn't sm21 show an errror when em is full?

There will only be an indication in the system log when the transaction is terminated due to EM exhausted with the name of the dump in the system.

To find out more you need to call Tx ST22 and analyse the relevant dump

2. ST22 only show one dump but it is related to file not found, not to a memory problem.
Shouldn't we have a dump for each process that could not allocate new memory in em?

The dump is recorded only in the event of a transaction failure which gets stored in the SNAP table.

When a WP exceeds the allocated EM ztta/roll_extension (Shared memory), it goes into PRIV mode and starts to use the heap memory (local memory) to complete the activity.

3. ST03/STAD do not show any process that have reached a value close to em.
Would you know how we could reached the max if all processes use much less?

The value for the paramater ztta/roll_extension defines the EM per user context and the total is defined by EM/TOTAL_SIZE_MB.

You already mentioned that you didnt notice any dumps related to memory in Tx ST22.

If you see EM was used up yesterday then kindly call Tx ST03N (Expert Mode)- Yesterday's date - Under Analysis Views - Select "Memory Use Statistics"

Here you can see the top transactions / users for memory consumption for one particular day.

4. How do you find em problems sources when you notice them?

You come to know about Memory problems when the users complains or when you proactively monitor the system for any issues.

In either case you analyse the dumps from Tx ST22 and also make analyse ST03N and ST02 details.

Once you have the details you check the memory related system parameters with the SAP parameter recommendations Notes appropriate to the OS and release.

If there is a need to adjust the memory settings you change it after you identify where the shortage is.

At the end of the day what matters is how much memory you have on the box for the application to use. Increasing the parameter values wont necessarily help you to get rid off the memory issues when there is no sufficient memory on the box.

Cheers

RB

[divyanshu_srivastava3]

check note 185185 from part B - for understanding memory consumption by an application.....

[Former Member]

Hi,

em value in ST02 is total amount of extended memory used mostly by all users contexts. ztta/roll_extension - maximum size of a user context in the SAP extended memory. In case you have no more extended memory for allocation for given user the system begin allocate heap memory for dialog workprocesses and set process to PRIV mode. The SAP system begin to generate dumps in case dialog/nondialog workprocess exceed ztta/roll_extension(ztta/roll_extension_nondia)+abap/heap_area_dia(abap/heap_area_nondia) amount of memory and need to allocate more memory.

Regards,

Roman

[benoit-schmid]

Hello Roman,

Your explaining that having em max reached does not generate dumps

because wp starts to malloc (allocate heap mem).

I agree with that.

This answers my question 2.

Basically it seems that SAP WPs could allocate enough heap when em exceeded.

Therefore there is no st22 dump.

But my questions 1, 3 and 4 are still not answered.

Isn't there is a systematic sm21 error when em is full?

As st03/stad reports no process that are close to even half of the max,

how could I reach the limit?

Which other tools/transaction do you use to find em problems sources?

Thanks in advance for your answer.

[Former Member]

>> Isn't there is a systematic sm21 error when em is full?

As you can see no. But you can configure alerts in CCMS if threshold was exceeded.

>> As st03/stad reports no process that are close to even half of the max, how could I reach the limit?

You have many users in system. Even if each of them have small amount of em allocated the total can be very high.

>> Which other tools/transaction do you use to find em problems sources?

ST02, SM04, ST03/STAD, CCMS monitoring.

Regards,

Roman

[benoit-schmid]

Hello,

Could you please provide me the rz20 menu hierarchy that you are using to monitor the em?

Roman N wrote:
As you can see no. But you can configure alerts in CCMS if threshold was exceeded.

Thanks in advance for your answer.

[benoit-schmid]

Hello,

In ST03, is there a better way of Analysis than using:

Memory Use Statistics -> Sort on ExtMem?

Roman N wrote:
You have many users in system. Even if each of them have small amount of em allocated the total can be very high.

Thanks in advance for your answer.

[Former Member]

Check the following:

SAP ERP Monitor Templates->

   ERP ABAP Application Server->

      <SAPSID>->

           <AppServer>->

                R3BasisSystem->

                    MemoryManagement

Regards,

Roman

[Former Member]

Hi,

refer below links you can get more information

http://scn.sap.com/thread/1643719

http://scn.sap.com/thread/626813

http://scn.sap.com/thread/2006226

With Regards,

V Srinivasan

[benoit-schmid]

Hello,

Srinivasan V wrote:
refer below links you can get more information
http://scn.sap.com/thread/1643719

This one is useless for me because, as I said previously, sm21 does not report anything.

No canceled report appear in sm37.

Regards,

[benoit-schmid]

Hello,

Srinivasan V wrote:
refer below links you can get more information
http://scn.sap.com/thread/626813

This one is useless for me because, as I said previously,

ST03/STAD do not show any process that have reached a value close to em.

The thread also mentions sm04 and sm50 that are useless for histtory diagnostics.

Regards,

[benoit-schmid]

Hello,

Srinivasan V wrote:
refer below links you can get more information
http://scn.sap.com/thread/2006226

This thread does not answer my questions.

It is also useless.

Regards,