Important Profile Parameters for the Lock Concept

System profile parameters are used to adapt the system as best as possible to the current requirements and resources. A general description of these parameters is provided under Profiles in the CCMS documentation.

Features

The following table describes the main profile parameters associated with the lock mechanism. You can obtain a complete overview by searching for the parameters with the entry *enq* in transaction RZ11.

Parameter	Description
`enque/table_size`	Size of the lock table managed by the enqueue server in the main memory. The lock table contains information about which locks are currently held by whom. Lock table overflows are recorded in the system log. In this case, you should check whether the update server is functioning correctly, since the lock table can grow very fast if the update function stops. If no update problems exist, you can use this parameter to increase the size of the lock table. The Computing Center Management System (CCMS) monitors the status of the lock table constantly and outputs warnings if the space available is not adequate. You can check the space available in the lock table by Displaying the Lock Statistics. Unit: Kilobytes Default value: 16384
`rdisp/wp_no_enq`	Number of enqueue work processes that are to run on this instance. Note Naturally, this parameter is set to `0` on all application servers on which the enqueue server is not running, since only the instance with the enqueue server can contain enqueue work processes. When you use the standalone enqueue server, the parameter is set to `0` on all instances. End of the note. Unit: Integer Default value: 0 The parameter on the enqueue instance is usually set to 1, that is, there is only one enqueue work process in the entire system. The parameter, however, can be set to 2-4 in large systems.
`enque/backup_file`	Complete path to the backup file. This is used to enter the locks, which are transferred to the update, in the lock table again after the enqueue server is restarted. For more information, see: SAP Lock Concept Unit:Character string (path name) Default value: UNIX platforms: `/usr/sap/<SID>/<instance>/log/ENQBCK` Windows: `/usr/sap/<SID>/<instance>/log/ENQBCK.DAT`

Parameter

Description

enque/table_size

Size of the lock table managed by the enqueue server in the main memory. The lock table contains information about which locks are currently held by whom.

Lock table overflows are recorded in the system log.

In this case, you should check whether the update server is functioning correctly, since the lock table can grow very fast if the update function stops. If no update problems exist, you can use this parameter to increase the size of the lock table.

The Computing Center Management System (CCMS) monitors the status of the lock table constantly and outputs warnings if the space available is not adequate.

You can check the space available in the lock table by Displaying the Lock Statistics.

Unit: Kilobytes

Default value: 16384

rdisp/wp_no_enq

Number of enqueue work processes that are to run on this instance.

Note Note

Naturally, this parameter is set to 0 on all application servers on which the enqueue server is not running, since only the instance with the enqueue server can contain enqueue work processes. When you use the standalone enqueue server, the parameter is set to 0 on all instances.

End of the note.

Unit: Integer

Default value: 0

The parameter on the enqueue instance is usually set to 1, that is, there is only one enqueue work process in the entire system. The parameter, however, can be set to 2-4 in large systems.

enque/backup_file

Complete path to the backup file. This is used to enter the locks, which are transferred to the update, in the lock table again after the enqueue server is restarted.

For more information, see: SAP Lock Concept

Unit:Character string (path name)

Default value:

UNIX platforms: /usr/sap/<SID>/<instance>/log/ENQBCK
Windows: /usr/sap/<SID>/<instance>/log/ENQBCK.DAT

Note Note

These are not all the profile parameters that are concerned with lock management. The default values are optimal for your system. Only let experts make changes to your system.

End of the note.

More Information

The most important profile parameters for updating are described under System Profile Parameters for Updating.

If you are using the Standalone Enqueue Server, you will find details of the relevant profile parameters in the section Profile Parameter Settings for the Standalone Enqueue Server.