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OpenTP1 Version 7 Description
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OpenTP1 enables an OpenTP1 administrator to construct an OpenTP1 system consisting of two duplicated server systems. Each server system consists of OpenTP1, a CPU, and a kernel. When one of the system fails, OpenTP1 can automatically switch to the duplicated system. The parts of OpenTP1 that enable this switching are collectively called the System Switchover facility.
After the system switches, you can automatically or manually restart the OpenTP1 system in which an error occurred and prepare for another system switch.
The system which handles work processing online is called the running system, and the other system is called the standby system. Whenever a System Switchover occurs during online processing, the standby system becomes the new running system, and the old running system becomes the new standby system.
The system can be switched even if the Message Control facility (MCF) or the Message Queuing facility (TP1/Message Queue) is installed in the OpenTP1 system.
There are two types of system switching:
In an automatic system switchover, the running system that has an error is automatically switched to the standby system. In a planned system switch, the running system that has an error is switched using an HAmonitor command.
In both types of switchover, you can treat several products as a group for switching. This is called grouped system switchover. In this type of switchover, when an error occurs in one of the products in a group of a running system, all the products in the group are switched to the standby system. In this operation, you can always use a group of products in the same running system together.
In a grouped system switchover, the timing of system switching may differ from the timing when the products are not grouped depending on the definition of HAmonitor. For details of the grouped system switchover, see the relevant HAmonitor manuals.
During the setup of HAmonitor, you need to decide which system starts as the running system in an online start. You must define the system which starts first as the primary system, and define the standby system ready for an error of the running system as the secondary system. The systems keep these names even after a system switch.
The following figure provides an overview of the System Switchover facility.
Figure 6-1 Overview of the System Switchover facility
![[Figure]](FIGURE/ZU060100.GIF)
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