678501 - System standstill, locks on NRIV

Version	4		Type	SAP Note
Release Status	Released for Customer		Language	English
Responsible	Doerte Goettsch ( D019862 )		Masterlanguage	German
Processor	Britta Vahl ( D020499 )		Last Changed On	04.08.2016 16:21:40
Component	BC-SRV-NUM ( Number Range Management )		Created On	07.11.2003 15:34:51

Symptom

System performance is poor. Locks on table NRIV are displayed in transaction DB01. In transaction SM50, you can see SAPLSNR3 processes with DIRECT READ on table NRIV.

Other Terms

NRIV, lockwaits, number range object, no buffering, DB01, SM50, SM66

Reason and Prerequisites

The missing buffering of number range objects may impede system performance considerably. The reasons for this are as follows: If number ranges are not buffered, the NRIV number range table is accessed with a database lock using 'SELECT SINGLE FOR UPDATE'. The interval in the table will then remain locked until the next commit or rollback and additional numbers cannot be retrieved from this interval. This causes a serialization of the application.
If other performance problems arise, the timespan until the COMMIT can become very long indeed. This means that more and more processes wait for NRIV until the system hangs.
IMPORTANT: The SAPLSNR3 program is not the cause of the problem, the poor performance is rather due to applications that are executed simultaneously and interfere with each other.
Refer to Note 572905.

Solution

To determine the affected number range object and thus the responsible application, proceed as described in Note 572905. Note 504875 contains information about the options for buffering number range objects. There is also a large number of application notes for specific number range objects. You can select these notes on the SAP Service Marketplace by using the number range object as search term.
SAP delivers most number range objects already buffered. If a number range object is delivered unbuffered, this is usually due to legal requirements in some countries which ask for sequential numbering without gaps. In these cases, you must determine if these restrictions apply to your country. In many cases, a type of buffering is possible. Refer to the following notes: 179224, 599157 and 840901.

Note that the change of the buffering type of the number range objects delivered in the standard system constitutes a modification and no support can thus be provided for resulting problems unless the modification is covered by SAP Notes for localization purposes. The modification is overwritten as soon as the affected number range object is redelivered - in other words, you must check the change manually each time you import a release.
Before changing the buffering of a number range object, please check carefully whether this is required - in legal terms.

If a number range object uses main memory buffering in the standard system, the buffering type should be changed only in the case of statutory requirements.