This document describes how to install and operate a Natural global swap pool in a Natural under UTM environment.
The following topics are covered:
If all tasks of a Natural under UTM application are terminated abnormally, the contents of a local Natural swap pool are deleted. Consequently, when a task is started again, a new swap pool is initialized and all users affected by the abnormal termination must start their Natural sessions again.
To avoid this situation, a global (that is, restartable) swap pool can be used: after an abnormal termination of the Natural under UTM application, when the users log on to the application again, the last screen displayed before the termination is sent again and the users can resume their session at the point where they were interrupted.
The following prerequisites are required for the installation of a global swap pool:
If a global swap pool is to be used, a global buffer pool must also be used. Before the restart of a Natural under UTM application, the global buffer pool must have been initialized; that is, at least one user must have used this buffer pool by normally starting a new Natural session.
If a new global buffer pool is started before an abnormally terminated Natural under UTM application is restarted, a new global swap pool must also be started. However, if a new global swap pool is started, a new global buffer pool need not be started as well.
The relation between the swap pool and the swap file is as follows: When
the first UTM task uses a newly started swap pool, the swap file is opened with
OPEN 'OUTIN', which means that the contents of the swap file are
deleted. When a subsequent UTM task uses an already used (initialized) swap
pool, the swap file is opened with OPEN 'INOUT', which means that
the contents of the swap file can still be used.
A Natural global swap pool must be started with program
CMPSTART. It can
be used from a maximum of five Natural under UTM applications.
To obtain information on the current parameters settings of the global swap pool, as well as the date and time of its start,
Issue the console command:
/INTRtsn,DPR
