EM parameters: History Table

[pietro_marovello]

Dear All,

I need to keep track of all the value changes of the control/info parameters of an event handler during the time: do we have a table in EM where are stored all the values assigned to the same control/info parameter?

Thanks,

Pietro

[pietro_marovello]

Hi Steffen,

is the customizing about "Log EH Posting", "Log Msg.Proc." and "Log exr.Updates" related to the "Change doc. Activation" functionality?

In case yes, if  I select "no logging" for the three options can I reduce the performance impact?

I checked it is enough in order to keep track of the parameters changes.

Best regards,

Pietro

[Former Member]

Hi Pietro,

Change Doc Activation different from Log EH Posting.

Change Doc Activation - This is gives Date, time, parameter, old value and new value, table etc that shows what changes has happened but will not give you in detail how it has happened .

You can find this in /SAPTRX/EH_LIST -> Event Handler Detail Overview -> Change Documents.

Log EH Posting", "Log Msg.Proc." and "Log exr.Updates - Gives you detail step by step how and what has happened during posting.  If you enable you can find the log in Tcode SLG1 and /SAPTRX/EH_LIST -> Display Event Handler Log(F7).

If you are posting less than 25000 events per day, it's ok to activate, however if high number of events posting then ensure that you have strong system resource planned to mitigate the risk.

Regards

GGOPII

[former_member190756]

Hi Pietro,

as Gopi said this has nothing to do with Change Documents. Loggings is normally used to find problems during processing e.g. in the rule set. In production you should switch off logging in any case and only enable it temporarily when needed.

Best regards,

Steffen

[pietro_marovello]

Thank you Gopi and Steffen for the clarification.

So, can I consider the number of 25000 events per day as a benchmark in order to decide the usage of "Change document" functionality respect on the creation of a custom table where are stored all the changes on the control/info parameter?

Best regards,

Pietro

[former_member190756]

Hi Pietro,

no. There is no benchmark for using Change Documents. This is used very seldom. A benchmark for events also makes no sense here. You should check how many change docuemnts are written in your scenario per EH update and Event Message processing. An then maybe check runtime with and without change document switched on. So you can calculate the overhead.

Best regards,

Steffen

[Former Member]

Hi Pietro,

If it's only a handful of parameters for which you want current and previous values, then go for a simple ZTable which can hold these values. This is better than activating change documents which logs every change happening to EH and which might be costly in terms of performance and space. You can build ZEH_PAR something like /SAPTRX/EVM_PAR table.

Thanks,

Vishnu

[Former Member]

Hi Pietro,

I have given the count because we didn't face any issue in our previous project which was count less than 25000.  However, it varies depends on project to project, based on number of fields extraction in System/Control/Info parameters etc.

You can check and simulate the scenario with performance testing team (if you have one) with activating change documents activation and posting events then you know what is resource require to achieve your expected results.

Regards

GGOPII

[pietro_marovello]

So, the only way to keep track of all the control/info parameters values during the time is the "change doc activation" functionality, but it can generate performance issues.

From a performance point of view, do you think it would be better to create a function module in the rule set where,  for the combination tracking ID-event code, I write all the received values of the parameters in a custom table?

Best regards,

Pietro

[former_member190756]

Hi,

yes if you only need to track changes for Info and Control Parameter this would be much more efficient.

But you should add also the EH Guid or AOID fields into the custom table. Tracking-Id and event is not unique.

Best regards,

Steffen

[pietro_marovello]

Yes, of course, I just mentioned that two fields to give an idea.

Thank you to everyone!

Pietro

[Former Member]

If you are loading/updating parameters through events, then use /SAPTRX/EVM_PAR table. This will store the history of parameters which got updated through various events. Only thing you will not be able to see are the parameters loaded through AOType during initial creation or changes to application data.

Thanks,

Vishnu

[pietro_marovello]

Hi Vishnu,

I know that table but I need something similar for control/info parameters, acquiring their values not from the Web UI but from an external system (using in the rule set the rule PARAM_CHANGE).

Best regards,

Pietro

[former_member190756]

Hi Pietro,

in screenshot above:

The flag Change Doc Activation does the logging of changes of all EH data inclduding control/info parameter.

Best regards,

Steffen

[Former Member]

Hi Pietro,

Steffen directed you correctly. Yes we can track control/info parameter through Change Doc Activation.  However, please ensure that you have enough resource requirement once you activate Change Doc Activation.  Most of the clients do not activate Change Doc and History in production systems due to performance issue and highly used storage resource.

Regards

GGOPII

[former_member190756]

Hi Pietro,

you could enable Change Documents on the EH Type.

This would also track changes on Control Parameters in standard SAP Change Document functionality.

You can see the changes then i a tab in /SAPTRX/EH_LIST.

But i would do not recommend it especially if you have a high volume of data. It will have a severe performance impact.

Best regards,

Steffen

[pietro_marovello]

Hi Steffen,

are you talking about the flag "Disable Expected event Historical data" in the customizing of the Event Handler types?

I tried to post the same event two times with two different values of a control parameter, but I was not able to keep track of the old value: where exactly I should see that information?

No other way to keep track of the historical data of a parameter? In case no, I think the only solution is the creation of a custom table...

Best regards,

Pietro

[n_soni]

Pietro,

For EH level, I see only one config that can enable historical data. Not sure if that covers control parameters

If these config is enabled, then check tables if that satisfy your requirement.

/SAPTRX/EH_EEHST               Event Handler Expected Event History Table

/SAPTRX/EH_MEHST               Event Handler Measurement History Data Table

/SAPTRX/EH_STHST               Event Handler Status History Table

For Event Message Parameter, you can get history from table /SAPTRX/EVM_PAR

Regards,

NRS

[pietro_marovello]

Hi NRS,

Yes, I just talked about that customizing, but nothing seems to deal about the historical data of control/info parameters..

Best regards,

Pietro

[Former Member]

Hi Pietro,

Those flags for historical data will not help in your parameter old and new issue. He was talking about change pointers I guess SCDO Tcode.