Meta-management of Dynamic Distributed Network Managers (MEMAD) [chapter]

Ran Giladi, Merav Gat
2000 Lecture Notes in Computer Science  
Distributed network management systems (NMS) have become a crucial necessity, especially for overcoming centralized NMS restrictions such as scalability and inefficient use of network resources. Such systems will also be instrumental in meeting the need for high-power computers and storage capabilities on the NMS platform. Modern technologies used in distributed NMS include management by delegating agents and mobile codes. These methods lead to the creation of a hierarchical architecture, since
more » ... it simplifies management of the distributed agents. Peer management results in a dynamic, survivable and efficient way of managing the network, but it requires a complicated metamanagement mechanism to handle the managers. This study suggests an architecture for this purpose. We term this model Meta-Management of dynamic Distributed network managers (MEMAD). The purpose of MEMAD is to enable Peered Distributed Managers (PDMs) to manage the network by executing delegated or predetermined common management tasks. MEMAD defines a small, shared, replicated, and partitioned database as well as inter-communication SNMP based primitives for providing PDMs with the ability to cooperate efficiently in managing the network. Ran Giladi and Merav Gat 120 In recent times, Web-based management systems have begun to use a technology that somewhat differs from SNMP systems in that the management station communicates with its users or applications via Web-based GUI (e.g., HTML, XML) [13, 15] . Webbased technology also allows Network Elements to respond with HTML pages instead of with SNMP, CMIP, or DMI messages to the management station [14] . In large and complex networks, the managers have to control a vast number of agents and perform all the information processing to the extent that the managers are loaded with information coming from all the agents. As a result, the managers' limited resources and network accesses bottleneck the management system. Additional problems such as increased network congestion, a high probability of disconnecting agents from the manager, slow responses from managers, and lack of redundancy have thwarted the centralized network management architecture from efficiently managing today's networks. Of late, we have begun to witness a new approach to network management that, in principle, decentralizes network management, or better yet distributes it. The distributed network management approach deals mostly with the distribution of network management applications by delegating management tasks to other management entities for execution. Modern technologies presently used in this kind of distributed network management are usually hierarchically structured, since management of the distributed agents is simple and inherent in such structures. Management by delegation (MbD) was among the first mechanisms to be proposed for hierarchical network management [2] . By delegating management tasks to specific agents, the manager's load is decreased and the tasks are executed close to the Network Elements (NE). This leads to a decrease in management traffic, higher availability of the NEs, and less dependency on the manager. However, for executing management tasks delegated by a manager, it has become necessary to devise a flexible and generic mechanism to serve as an extension to the agent. Another approach to hierarchical network management [3] introduced the SubManager as a dual function entity. This manager delegates management tasks to the SubManager with access authorization to the relevant NEs and their agents. The SubManager then executes the task while polling the agents for the required information. This hierarchical model uses an SNMP framework and extends the Management by Delegation model by enlarging the scope of management of the dynamically extended entity (the SubManager). Other approaches to distributed network management that have been suggested include the addition of RMON (remote monitoring) capabilities [4] to the executing entity [5], or the use of a Mid-Level-Manager and SNMP protocols. In the latter, the Mid-Level-Manger is provided with a new MIB (management information base) definition [6], which makes it possible to receive delegated management scripts and execute them on the NE agents, as well as other distributed management tasks. Recent technologies, such as mobile code, have resulted in the Mobile Agent [7] approach. This technology implements the delegation mechanism in a slightly different manner, in that in order to achieve better network resource utilization, every management task is delegated and executed by several agents and servers. The use of recent technologies, such as mobile code, intelligent agents, etc. [8-10], provides more sophisticated and efficient distributed methods than the various hierarchical
doi:10.1007/3-540-44460-2_11 fatcat:l6qqxl2ntza5foo7gvzdcrsj5q