A state is one of a set of predefined possibilities for the condition (for example, up, down, or unknown) of the managed object.
A change in state appears on the WorldView 2D Map or in Management Command Center, as a change in icon color. You can drill down through the network topology, to the machine name or IP address, to Unispace, and to the agent that communicated the state change. From the pop-up menu associated with that agent, you can view the current state of the agent according to the DSM (from Node View) or according to the agent (from Agent View).
Each layer of Unicenter interprets the state of a managed object differently, placing an emphasis on different aspects of the object. For example, a Windows 2003 server may be taken off-line for repairs. The Windows 2003 system agent stops sending information to its DSM. The state of the agent according to the DSM is Absent, indicating that no information is being relayed. However, the state of the agent according to WorldView is Down, indicating that the server is inaccessible.
Knowing how the Monitoring Layer reacts to a breach in a predefined limit (threshold) will help you understand how communication moves throughout your enterprise and how information about monitored resources is conveyed. It will also help you respond to and resolve any problems when they occur.
The following steps outline what occurs architecturally when a threshold breach on device is detected:
The manager layer provides control of the day-to-day operations of your IT infrastructure. The Manager Layer consists of the Distributed State Machine (DSM) and its supporting components. The DSM interprets data collected and makes that information available to applications such as WorldView and Node View. The DSM can run on Windows and UNIX/Linux platforms.
The Manager Layer includes the following components:
These components run as processes that can be started and stopped independently, or as a group, by the Agent Technology Service Control Manager (awservices). To view the Service Control Manager, see the section Tools to Configure Managed Resources. A brief explanation of each component follows.
For more information about any of these components, see the guide Inside Systems Management.
The Service Control Manager, or the Agent Technology Services Manager, displays the status of each DSM component. You can access the Agent Technology Services Manager from its own window. For more information, see Tools to Manage Resources.
The Distributed Services Bus manages communication between all the other Agent Technology components. All information exchanged is placed on and retrieved from the Distributed Services Bus.
The SNMP Gateway encodes requests into SNMP Protocol Data Units (PDUs), sends them to SNMP agents in the management domain, and receives and decodes get response and trap PDUs from the agents.
DIA (Distributed Intelligent Architecture) is a proprietary, encrypted, high-speed facility. You can use the DIA Gateway enterprise-wide only if all agents are running NSM r11, r11.1, or r11.2. Otherwise, SNMP is required for all other agents. DIA is covered more fully in the earlier chapters of this guide.
The Trap multiplexer (MUX) allows multiple management applications to listen for traps on the same trap port. For example, Enterprise Management and the DSM both listen to port 162.
Agent Technology provides a mechanism for the persistent storage of objects, called the object store. The Object Store stores class data on managed objects. Managed object class definitions are loaded into Object Store from DAT files. The DSM uses the class definitions in Object Store to discover agents and managed objects on the appropriate nodes.
The Distributed State Machine controls the discovery of agents and monitored resources in the enterprise and maintains the status of these resources based on information received from remote agents. The DSM also converts trap data, poll responses, and user actions into current object states. The DSM interprets data collected by agents and then makes that information available to applications running on Windows and UNIX/Linux platforms.
The DSM evaluates information received from managed nodes by way of the SNMP/DIA Gateway. The DSM determines what managed object the information pertains to and what the information is saying regarding that object. The DSM has logic for each managed object, which it uses to determine if there has been a change in state.
The DSM stores managed objects and their current states in memory. When the DSM is stopped and restarted, it obtains the last reported state for each previously monitored object and the instance-level properties for those objects.
The DSM Store contains DSM managed objects that represent network nodes, agents, and the resources that are being monitored. These managed objects are created each time the DSM starts up during the DSM discovery process. The DSM uses the managed objects to maintain the current status of monitored resources in its domain.
Each DSM managed object has associated property values assigned based on the class definition that is present for that type of object in the Object Store. An object’s current state is one property value maintained by the DSM.
The DSM is self-managing to ensure that your resources are under constant surveillance and that the health and load of each DSM can easily be determined. DSM Monitor uses various data collection methods to effectively monitor the DSM process, its impact on CA NSM, and its impact on the performance of the server on which it runs. You can use the historical data collected to fine tune the DSM-managed enterprise by balancing the number of managed objects and classes across multiple DSMs.
The WorldView Gateway communicates with MDB through the WorldView Application Programming Interface (API) to get information about any nodes that WorldView has discovered. The WorldView Gateway then filters the list of discovered nodes based on the contents of the DSM Configuration IP Scoping Table, and forwards the appropriate list of managed objects to each DSM.
For example, if DSM1 is configured to manage only devices with IP addresses 172.16.0.0 to 172.52.255.255, then the filtered list provided to DSM1 by WorldView Gateway would include only the addresses of any devices discovered within that range.
The WorldView Gateway also filters the list of nodes based on the node class. This information comes from the Class Scoping Table, which contains a list of the node classes that the DSM should monitor. Another task of the WorldView Gateway is to pass state change information from the DSM to the MDB.
Knowing how the Distributed State Machine (DSM) discovers your resources and determines their state will help you understand how CA NSM communicates throughout your enterprise and how it conveys information about monitored resources. It will also help you respond to and resolve any problems when they occur.
During its operation, the DSM moves through the following steps:
The WorldView layer represents your entire CA NSM enterprise. This layer contains the WorldView 2D Map and Management Command Center, through which you can view all of your monitored resources and their relationships, such as which monitored resources appear on which nodes.
The WorldView layer includes the following components:
For more information about WorldView, see the appropriate chapters in this guide.
When WorldView detects a problem in your network, someone must locate the specific resource that is generating the alert and resolve the problem. CA NSM provides a number of interfaces that let you stop and start services, view monitored resources, and modify their thresholds or properties.
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