Zero Downtime Option for SAP S/4HANA

Locks on the Bridge Subsystem

This section is about the locks on the bridge subsystem.

During the update procedure, the bridge subsystem communicates with the tables that are affected by the update. To avoid collisions between the update and the users who work on the bridge subsystem, locks are implemented on the bridge subsystem. These locks can be set by the following processes:

Process

Comment

Table conversion

At the beginning of the update, affected tables become read-only to prevent them from being modified.

After-import methods (AIM)

At the end of the update, affected tables are locked to prevent them from being modified. In this case, you receive an error message with the user usr_persist.

The following locks are implemented in addition:

Lock

Comment

EU_LOCK

At the beginning of the update, a generic lock is set for affected tables and applications.

Client locks

At the beginning of the update, after-import methods (AIM) lock tables that are affected by the update. These tables remain locked until the update is completed.