Administration of the Number Range Buffer 

Use

Transaction SM56 is used for the administration of the number range buffer.

You can make other settings in the profile parameters.

Integration

The technical functions and the settings are described in the How the Number Range Buffer Works.

Prerequisites

In the number range object maintenance (transaction SNRO) you have activated buffering in the main memory for a number range object. You must have created a number range object or selected an existing one on the initial screen of SNRO and then chosen No. Range Object: Change (Edit →  Set-Up Buffering → Main Memory) (see Maintaining Number Ranges).

Features

When you call transaction SM56, you can see the statistics of the number range buffer.

Statistical Information

The top screen area contains general information about the statistics.

Information	Meaning
Max. no. of entries	Maximum number of entries in the buffer (see profile parameter nobuf/max_no_buffer_entries)
Current no. of entries	The number of entries currently occupied in the buffer
Max. no. of indexes	Size of an internal administration structure. Normally you can see three times as many entries here than in the actual buffer.
Current no. of indexes	Number of occupied entries in the internal administration structure.
Size	Memory requirement of the buffer in bytes
Buffer calls	Number of calls made to the buffer. (There are other functions too, which are not counted. These are also used by the function group NUMBER_GET_NEXT).
Get calls	Number of calls that are counted
Server calls	Number of calls made to the number range server
Database calls	There are also database calls that are not made within the context of the number range server. These calls are included in the count.
Collisions	SAP internal value for error analysis
Timeouts	If a process wants to assign a number and has to wait because another process is blocking the lock of the buffer or interval, it waits for a specified length of time (nobuf/max_attempts in seconds). Once this time has elapsed, an error is notified to NUMBER_GET_NEXT. The process then tries to assign a number directly from the database. This value shows how often this timeout has occurred.

Under buffer times and server times you can see the distribution of the times calls were made to the number range buffer and to the number range server. Using both distributions you can work out how much time is saved with using the number range buffer.

Buffer Entries

To display the entries in the number range buffer, choose Goto → Entries. You can limit the selection in the next dialog box.

You can then see the details of each interval in the buffer. On the left-hand side you can see administration data for the entries (client, number range object, subobject, interval number(range), year, and whether the interval is external).

On the right-hand side are the following details:

·        From number, To number: number range of the interval

·        Release: current status of the interval in the buffer (this is not the status of the interval in the database).

·        Critical No: the number after which the application is warned by NUMBER_GET_NEXT that the numbers will shortly run out.

·        Buffer to No.: the number up to which numbers can be assigned from the buffer. Once this number has been reached, the number range server must fetch new numbers from the database and put them in the buffer (see How the Number Range Buffer Works).

Reset Buffer

To delete entries from the buffer, choose Number Range Buffer → Reset. This happens automatically when an interval is changed or deleted in transaction SNR0 (or in the application-specific number range maintenance). This mechanism prevents any incorrect numbers still in the buffer from being assigned. You can also perform this action manually from the above menu path. A dialog box appears where you can specify which records you want to reset. If you select the indicator Global reset, the buffer entries on all application servers will be deleted. If the indicator is not selected, only the buffer entries on the current application server will be deleted.

Check Buffer

This function is used by SAP support to facilitate the analysis of any problems that may occur in the number range buffer.