Locks in SM12, why ?

[Former Member]

Hello All,

As we are facing many locking issue when the users load the huge numbers of CVCs in the planning book which results in over-flowing of the lock table & system throws error like " Unknown Error" . Just want to know, want to under what conditions locks are found in SM12. Please writeback..

Thank you

Regards

Rahul Chitte

[aparna_ranganathan · Accepted solution]

Hi Rahul ,

As Senthil and Satyajith have mentioned , when you try to update a database table , then one or more lock entries will be created based on how many data base tables are affected . It is a good practise to avoid locking lot of entires at once. For example if you want to update 1000 marc records , then around 3000 lock entries may be consumed at a stretch. But this may affect the performance of other processes that are running in parallel. Sometimes the number of locks consimed may exceed the limit set for that server. So when lot of records are to be updated, it is good to do the update in batches instead of doing it in bulk.

Thanks

Saradha

[Former Member]

Thank you !

[Former Member]

Hi Rahul,

Memory overflow takes place when too many locks are there which are not getting released and have to be done manually through SM12. These locks happen if a very memory intensive operatin is executed interactively. e.g. loading large number of materials in planning table and then executing some transaction interactively like heuristics, other e.g. is like trying to download some master data from the sytem in foreground. Secondly when these locks are created in large number the system chokes and users are not released even if they have logged out of a transaction. This gets into a vicious circles and these locked entiries multiply very fast since if the data is accessed from the table this results sometines in LC crashing also.

If this is not the case and as usually even if few lockes are there and are not getting released then you need to contact your Basis team to update the Patch level or apply some notes to overcome this problem. Your Basis team can from Service market place find out the relevent notes.

Thanks,

Harsh

[Former Member]

Hi Rahul,

Please try sap note 1311785 to fix your problem.

Regards

R. Senthil Mareeswaran.

[Former Member]

Hi Rahul,

"Just want to know, under what conditions locks are found in SM12." If any user is processing some data then those are locked. and In sm12 we can see the user specific lock data.

Some times a back ground job is running (by some user) and at the same time someone is trying to change or midify those data, which are being processed by the job. Or some other background job is running at the same time which is also processing the same data (frequent in parallel processing) or for some other purpose . In that case there are probablity of getting errors.

Thanks,

Satyajit

[Former Member]

Hello Satyajit, Thank you very much for your reply..

You said"If any user is processing some data then those are locked. and In SM12, we can see the user specific lock data" * is absolutely correct*.

But, when two users are out from the transaction or logged off from APO (who are using the same data & got locked in SM12 ) still the locks persits their IDs & caused problem for other users. i.e. they cant upload the CVCs in the planning book.System throws __"Unknown Error"__ Here, the lock table gets overflowed.

So my question is why thoses entry remain in SM12 ( unless they have to be deleted ) even though the users are logged off from APO. Any clue to fix this .... any note or ABAP amendations needed ?

Please write back

Thank you

Regards

Rahul Chitte

[Former Member]

Rahul,

Though the user is logged off from APO, but still the data can be locked by background job set by the user. But I think it may not be your case. Practice is that we schedule bg jobs at night, when there are no user working.

You can try for that note mentioned by Senthil.

Please ensure that your default is set to display mode when entering planning books in APO. To check this: Select System\User Profile\Own Data, then select parameter tab.

In our case Parameter ID:/SAPAPO/SDP94_D_MODE

Parameter Value: I (capital i).

Thanks,

Satyajit

Edited by: Satyajit Patra

[Former Member]

Hi,

Locks are found because of one and only one cause:

Related data is in process(direct/indirect/reference processes)

e.g.: if you are processing Bill of material.

then lock will be found because of processing of bill of material.

2ndry: if doing BOM, then material master is linked. so that related data will be locked.

Regards,

Santosh