1.2.3 Server

HA Monitor performs the hot standby operation in units of servers. The term server is used in the meaning of a program.

Organization of this subsection

(1) Types of servers
(2) Server operating methods

(1) Types of servers

Servers are classified into the following two types, depending on the program:

Program with an HA Monitor interface

This type includes programs that have an HA Monitor interface, such as OpenTP1 (TP1/Server Base) and HiRDB.
Program without an HA Monitor interface

This type refers to all programs other than the programs with an HA Monitor interface. Examples of this type of program are JP1, Cosminexus, Oracle, and UAPs.

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(2) Server operating methods

The server operating methods include the server mode and the monitor mode.

The following table compares the server mode and the monitor mode.

Table 1‒1: Comparison of server mode and monitor mode
Comparison item	Server mode	Monitor mode
Comparison item	OpenTP1 (TP1/Server Base) or HiRDB	Monitor mode
Failures detected by HA Monitor	Server failures Host failures	Server failures^#1 Host failures UAP failures^#2
Server monitoring	Performed by HA Monitor	Performed by the user^#1
Unsupported HA Monitor functions	None	Detection of server slowdown^#3 Host pair shutdown^#3 Specification of hot standby type during grouped-system switchover Some user commands Acquisition of server monitoring history Advanced startup of the server in the standby system ...
Required settings	Environment settings for server support	Environment settings for server support Environment settings for programs in the monitor mode^#2 Creation of a server start command (If necessary) creation of server termination and server monitoring commands Creation of program restart commands (when necessary)^#2 Including APIs in UAPs^#2
Unit of one server	One program	One or multiple programs

#1: If a server monitoring command has been created by the user in advance, the user can then monitor the server in the monitor mode and detect server failures. When the monitor-mode program management function is used, HA Monitor monitors UAPs. For details about the program management function, see 3.6 Function for controlling programs (monitor mode).

#2: This applies only to programs that use the monitor-mode program management function.

#3: If a monitor-mode server is monitored by specifying the ptrlcmd_ex operand in the server environment definition, this function can be used (this event can be detected).

For programs with an HA Monitor interface

You can choose either the server mode or the monitor mode as the server operating method. We recommend that you choose the server mode when you use a program with an HA Monitor interface.

A server that runs in the server mode is also called a server with an HA Monitor interface. However, in this manual, such a server is called a server in the server mode.

For programs without an HA Monitor interface

Programs without an HA Monitor interface run in the monitor mode. No other server operating method is supported for them.

A server that runs in the monitor mode is also called a server without an HA Monitor interface. However, in this manual, such a server is called a server in the monitor mode.

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