Networks cannot be managed without management plane communications among geographically distributed network devices and control agents. Unfortunately, the mechanisms used in commercial networks to support management plane communications are often hard to configure, insufficiently secured, and/or suboptimal in performance. This paper presents the design and implementation of the Meta-Management System (MMS), a network-layer subsystem that provides robust autonomic support for management plane communications. We demonstrate the practicality of the MMS via a fully functional implementation that runs on commodity hardware, and experimentally show that the MMS is efficient and scalable. The MMS software is freely available.

One of the challenging problems for software developers is guaranteeing that a system as built is consistent with its architectural design. In this paper, we describe a technique that uses runtime observations about an executing system to construct an architectural view of the system. In this technique, we develop mappings that exploit regularities in system implementation and architectural style. These mappings describe how low-level system events can be interpreted as more abstract architectural operations and are formally defined using Colored Petri Nets. In this paper, we describe a system, called DiscoTect, that uses these mappings and we introduce the DiscoSTEP mapping language and its formal definition. Two case studies showing the application of DiscoTect suggest that the tool is practical to apply to legacy systems and can dynamically verify conformance to a preexisting architectural specification.

One of the challenges for software architects is ensuring that an implemented system faithfully represents its architecture. We describe and demonstrate a tool, called DiscoTect, that addresses this challenge by dynamically monitoring a running system and deriving the software architecture as that system runs. The derivation process is based on mappings that relate low level system-level events to higher-level architectural events. The resulting architecture is then fed into existing architectural design tools so that comparisons can be conducted with the design time architecture and architectural analyses can be re-run to ensure that they are still valid. In addition to the demonstration, we briefly describe the mapping language and formal definition of the language in terms of Colored Petri Nets.

One of the challenging problems for software developers is guaranteeing that a system as built is consistent with its architectural design. In this paper, we describe a technique that uses run time observations about an executing system to construct an architectural view of the system. With this technique, we develop mappings that exploit regularities in system implementation and architectural style. These mappings describe how low-level system events can be interpreted as more abstract architectural operations. We describe the current implementation of a tool that uses these mappings, and show that it can highlight inconsistencies between implementation and architecture.

The use of predicates to state constraints in Constraint Satisfaction is explained. If, as an alternative, the traditional approach of Integer Programming (IP) is used, it is desirable to model these constraints so as to give as tight a linear programming relaxation as possible. One of the most commonly used predicates is the “all_different” predicate. Different applications of this are described together with different IP formulations. The facet defining constraints for the convex hull are then described and proved to be facet defining.