Introduction to Control-O/COSMOS

This chapter includes the following topics:

Introduction

Control-O/COSMOS monitors objects (started tasks, terminals, disks, and so on) in your computing environment, and maintains each object in a status specified by the user. If the desired status of an object changes, Control-O/COSMOS performs the actions necessary to bring the object to its new desired status.

For example, if CICS is up but it becomes necessary to bring CICS down, the desired status of CICS can be changed to DOWN and Control-O/COSMOS takes the steps necessary to bring CICS down.

Object Status

Two types of status are relevant for each Control-O/COSMOS-controlled object:

  • Current status – Current status of the object.

  • Desired status – Preferred status of the object.

When the desired status and the current status match (for example, when both the current status and the desired status of object CICS are UP), no changes are necessary regarding the object.

When the desired status and current status of an object do not match (for example, the current status of the CICS object is DOWN and the desired status is UP), Control-O/COSMOS detects this and proceeds with actions designed to bring the object to the desired status.

Desired status of objects is set initially according to an option chosen by the user during Control-O/COSMOS startup. The user can then modify the desired status using:

Direct user intervention is not necessarily required to change the desired status of an object. Use of Control-O rules can often replace direct intervention. Once the appropriate rule is defined, the changing of the desired status of the object can be initiated by the rule.

Component Overview

The following concepts and components are central to Control-O/COSMOS functionality:

Table 1 Control-O/COSMOS Concepts

Concept

Description

Databases

A set of AutoEdit variable databases that store information for managing Control-O/COSMOS-controlled objects.

Rules

Control-O rules specifically designed to manage Control-O/COSMOS databases.

Commands

Commands that affect Control-O/COSMOS operations and the information in Control-O/COSMOS databases.

Screens

Screens that enable the user to view and modify Control-O/COSMOS information.

These components are described briefly in this section, and in detail in Component Details.

Control-O/COSMOS Databases

The following AutoEdit databases are used by Control-O/COSMOS:

For information on managing several machines within the same Sysplex, see Using Control-O/COSMOS to Manage a Sysplex.

Object Databases

As mentioned earlier, Control-O/COSMOS monitors objects (started tasks, I/O devices, and so on) in the environment and maintains those objects in their specified desired status. It is therefore necessary to provide Control-O/COSMOS with a list and description of those objects. This information about Control-O/COSMOS-controlled objects is stored in Object databases.

Each row in an Object database contains information about a specific object (for example, object name, class, current status, desired status and mode). Multiple Object databases can be defined.

Control-O/COSMOS periodically scans the current and desired status for each object in the Object databases. If the current and desired statuses for an object do not match, Control-O/COSMOS attempts to bring the object to the desired status (meaning, so that the current status matches the desired status).

Object databases must reflect your current computing environment. They can be generated manually, or they can be automatically generated using the SYSIMAGE facility, as described in SYSIMAGE Facility – Automatic Generation of an Object Database.

Attributes of the objects in the Object databases can be modified by the user at any time to reflect desired changes in the environment or changes that have already occurred.

Prerequisite Database

In many cases, prerequisite criteria must be satisfied before the status of an object is changed (for example, VTAM must be up before CICS can be activated).

It is therefore necessary to provide Control-O/COSMOS with appropriate prerequisite information so that Control-O/COSMOS can ensure that prerequisites are satisfied before changing the status of an object. This prerequisite information is stored in the Prerequisite database. Each row in the Prerequisite database describes an object that must be up before another specified object is brought up.

Before attempting to change the (current) status of an object, Control-O/COSMOS checks the Prerequisite database for prerequisite criteria that must be satisfied.

If all prerequisites for changing the object’s status are satisfied (or if there are no prerequisites), Control-O/COSMOS triggers a rule that modifies the object’s status.

If certain prerequisites are not satisfied, the change is not performed at that time (for example, if VTAM is not up, CICS is not started). Control-O/COSMOS, however, continues to scan the Object and Prerequisite databases. This is important because environments are dynamic, and a prerequisite that is not satisfied at one point in time may be satisfied at a later time. (If, for example, VTAM is brought to an UP status, and therefore the prerequisites for starting CICS are satisfied, Control-O/COSMOS starts CICS the next time it scans the databases.)

All objects referenced in the Prerequisite database must be Control-O/COSMOS-controlled objects (meaning, objects defined in a Control-O/COSMOS Object database).

Method Databases

When a change to the status of an object is to be performed (that is, when the current and desired status of the object do not match and all prerequisites are satisfied), Control-O/COSMOS needs to select the appropriate Control-O rule to perform the actions that bring the object to its desired status. These rules are referred to as Method rules. Information that indicates which Method rule is appropriate for performing the desired change to an object is stored in Method databases.

Each row in a Method database defines a method. A method consists of the particular type of change and the Method rule that can bring about the change. Each row (method) lists an object, object class, current status, desired status, and the name of the Method rule that is used to affect the desired change.

For example, a row in a Method database may indicate that the method defined in the row is used for modifying an object named CICSTEST with a current status of DOWN and a desired status of UP. When invoked, the Method rule specified in this row performs actions that bring the object to a status of UP.

Multiple Method databases can be defined.

Control-O/COSMOS Rules

A collection of predefined rules is supplied with Control-O/COSMOS. These rules detect and intercept changes in the computing environment, update the Object databases accordingly, and periodically verify the accuracy of information in the Object databases. Some types of rules supplied with Control-O/COSMOS are:

  • Rules that perform actions required to modify the current status of Control-O/COSMOS-controlled objects (meaning, Method rules).

  • Rules that intercept initialization and termination messages of common started tasks (for example, CICS, DB2 and JES2), and update the current status of these tasks in the Object database.

  • Rules that intercept Start and Stop commands and set the desired status of appropriate objects to UP or DOWN instead. (Control-O/COSMOS detects the change in the desired status the next time it scans the Object database, and implements Method rules specified by the user to bring the object to the desired status.)

  • Rules that periodically check if the values in the Object database represent the real situation in the system.

  • Rules that execute Control-O/COSMOS commands, described in Component Details.

When implementing Control-O/COSMOS to handle IPL and shutdown processes, ensure that other existing rules do not overlap. To avoid this, it is recommended that you implement Control-O rules, handling IPLs, or shutdown procedures as Method rules. For more details on Method rules, see Method Databases.

Control-O/COSMOS Commands

A variety of commands are provided with the Control-O/COSMOS facility. These commands can be divided into the following groups:

  • Commands that affect the operation of Control-O/COSMOS.

  • Commands that perform actions on Control-O/COSMOS-controlled objects. Many of these commands perform actions that can also be performed using Control-O/COSMOS online screens (described below).

Most Control-O/COSMOS commands trigger Control-O/COSMOS rules that perform desired actions. These command rules can be modified, which enable you to customize the Control-O/COSMOS facility according to your preferred operating procedures (for example, to issue Shout messages describing the action performed)

Control-O/COSMOS Online Screens

Online screens are provided with Control-O/COSMOS. These screens are primarily used to manage ongoing operations. They are accessed using option OC of the IOA Primary Option menu. The following Control-O/COSMOS screens are available:

Table 2 Control-O/COSMOS Screen Types

Screen

Description

Object Status screen

Displays objects and allows actions (for example, changing operation mode) on individual objects.

Database Status screen

Displays a list of Object databases and allows actions on all objects in a specific database or multiple databases.

Options of the Control-O/COSMOS online screens can also be implemented by various operator commands, described in Component Details. For more information about Control-O/COSMOS online screens, see Online Facilities.

Control-O/COSMOS Security

Control-O/COSMOS security is handled by two security modules:

  • IOASE42 – Protects the definition and administration of the IOA Global variables database. For more information, see the IOASE42 section in the INCONTROL for z/OS Security Guide.

  • CTOSE04 – Verifies user authorization to specific Control-O/COSMOS Online entities. For more information, see the CTOSE04 section in the INCONTROL for z/OS Security Guide.