A given process component will know at any given point in time exactly the peer components from which it may expect to receive information. It will also know which of those components may be providing directive information (directly or indirectly from the privileged user) or collected, computed, or report information. This knowledge will be used, in part, to ensure security. It will also be used, in combination with the type of information received, and possibly based on some part of the information, whether to use the information actively or pass it along, and to where. Similarly, each process component will maintain information on where it might be forwarding information it generates or receives, and does not retain.

• All process components will know its peer(s), parent(s), as well as nodes that provide collected, computed, or report information
• This will provide security and as a way to distribute information

In some cases it will make sense for a given process component to have primary and secondary destinations for certain types of information. For example, if a specific display device is inoperative, a report might best be written to a file, rather than discarded. This capability will be implemented in a future version of the application.

• Primary and secondary destinations must be configured for each component to eliminate loss of data in the case of a failure
• This capability will be implemented in a future version of the application

5.2 Network Management Application Configuration Change Control

As previously specified, the Network Management Application shall maintain high availability without imposing excessive processing or communication bandwidth consumption on operational components of the network. This shall be achieved, in part, via an explicit distributed architecture.

High availability is achieved by ensuring that for every operational component of the application a duplicate, equivalent component (or set of components) may be launched in a different computer system should the primary component, or the system in which it resides, become unavailable. In network segments where there is a peer node that has access to the same network components as a node in which a process component function resides, one backup process may be sufficient. This might be the case, for instance, in an Ethernet network segment. In other cases it may be necessary to have two or more backup processes to replicate the same management capability. Whenever a process component becomes unavailable, the parent or some peer process component will detect this situation and ensure the duplicate process component(s) go(es) into operation, inheriting the abandoned work load. It is required that every process component be backed up in this manner.

• A peer node must be able to take over a component (or set of components) should the primary component, or the system in which it resides, become unavailable
• This transition will be facilitated by their parent node
• Every process component must be backed up this way

Controlled performance impact is achieved by providing target resource consumption thresholds for the network management processes. Each process will monitor its utilization of resources and will alarm another (parent) process when the threshold is being exceeded. It will then cooperate with the parent process in spawning a helper process component in a different processor and / or using different communication link resources, depending on which resource (CPU, memory, or link bandwidth) is being over utilized. In particular, some of the task assignments of the busy process component must be reassigned to the helper process. Spawning the helper and distributing the work load shall take place before the specified threshold is actually exceeded.

• Thresholds will be set for "resources" (CPU, memory, or link bandwidth)
• Each process component will self-monitor its utilization of its resource
• If the resource is over-utilized, parent process will be notified so that alternate process components may be started on elsewhere.

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CSC405, Spring '96
Distributed Network Manager (DNM) Distribution Control