Motomitsu Adachi

Policy Verification and Validation Framework Based on Model Checking Approach

Policy-based management is drawing attention as a solution to managing todays complex information systems. To be dependable, a policy-based system must be able to check the validity of a policy written by administrators. However, common test methods such as operations tests in a test scenario and simulations cannot check whether systems with given policies will work properly in every possible situation. To solve this problem, we propose a policy verification and validation framework based on model checking that exhaustively verifies a policys validity by considering the relations between system characteristics and policies. We first define the validity of policies and the information needed to verify them from the viewpoint of model checking. We then construct our policy verification framework based on the definition and, finally, present a case study applying this framework to an on-demand data center scenario and show the effectiveness of our approach.

NEPRI: available bandwidth measurement in IP networks

To provide a consistent quality of service in IP networks, it is necessary to know the current performance and available bandwidth of the network adequately. There are some ways to obtain the current available bandwidth such as management information base (MIB) analysis and RMON monitoring. The measurement methods using probing packets are studied, but they require a large number of packets to be transmitted in order to improve the measurement accuracy. They create heavy network traffic, so it is difficult to use such methods for actual networks in use. To solve the problem, we propose a new method called NEPRI. This method detects the macroscopic behaviour of the probing packets queued at the bottleneck and estimates the available bandwidth of the path. We show our method consumes less network resources and is sufficiently accurate.

A policy based networking architecture for enterprise networks

We describe a new concept for policy based systems management (PSM) and propose its component functions. PSM aims to reduce the total cost of ownership (TCO) while providing highly functional enterprise systems that include enterprise networks. Conventional enterprise systems have been managed manually by humans, and are not able to provide a highly functional service with low TCO. For this reason, the policy based networking (PBN) approach is gaining attention. This paper describes the PSM that extends PBN for total systems management and shows the effectiveness of PSM functions with an example of dynamic QoS configuration.

Constraint Verification for Concurrent System Management Workflows Sharing Resources

Workflow is an effective way to define and specify the behavior of autonomic systems which manage themselves. However, when a system is working following several workflows sharing resources, it is very difficult to analyze the behavior of the systems with mutual influences between workflows due to the shared resources, and to decide whether problems may be caused by such mutual influences, despite the need to do so in order to develop trustworthy autonomic systems. To solve this problem, we developed a verification framework to identify whether constraint violations could occur in a system working and following workflows sharing resources. In this paper, we initially define the system management workflows. Next, we show the procedure to translate these workflows into hybrid automata, with the mutual influences between workflows taken into consideration. Finally, we show how to detect possible constraint violations by adopting a model checking technique to the hybrid automata through a case study.

The human interface in a multifunctional communication terminal

An intelligent human interface for a multimedia communication terminal, the Imagephone, is presented. Its adaptive user interface control system (which adjusts the timing of messages to the users ability) and its object-oriented software are described. The interface of the Imagephone proved efficient for a small communications terminal, but there is room for expansion. The object-oriented approach was found to be very effective. Use of C and a general-purpose operating system make the step from prototype to a commercial product a simple one. >

THE HUMAN INTERFACE IN A MULTIMEDIA COMMUNICATION TERMINAL

New multimedia communication networks such as ISDN and office Automation communication systems are being rapidly introduced into existing communication networks. Easy-to-use human interfaces are important to bring out the full potential of these advanced networks. This paper describes the human interface in a multimedia communication terminal, the Image Station.

Process Mining for Job Nets in Integrated Enterprise Systems

Batch jobs such as shell scripts are used to process large amounts of data in large scale enterprise systems. They are cascaded via certain signals or files to process their data in the proper order. Such cascaded jobs are called “job nets”. In many cases, it is difficult to understand the execution order of batch jobs in a job net because of the complexity of their relationships or because of lack of information. However, without understanding the behavior of batch jobs, we cannot achieve reliable system management. In this paper, we propose a method to derive the execution pattern of the job net from its execution logs. We developed a process mining method which takes into account the concurrency of batch job executions in large scale systems, and evaluated its accuracy by a conformance check method using job net logs obtained from an actual large scale supply chain management system.