3 research outputs found
High availability using virtualization - 3RC
High availability has always been one of the main problems for a data center.
Till now high availability was achieved by host per host redundancy, a highly
expensive method in terms of hardware and human costs. A new approach to the
problem can be offered by virtualization. Using virtualization, it is possible
to achieve a redundancy system for all the services running on a data center.
This new approach to high availability allows the running virtual machines to
be distributed over a small number of servers, by exploiting the features of
the virtualization layer: start, stop and move virtual machines between
physical hosts. The 3RC system is based on a finite state machine, providing
the possibility to restart each virtual machine over any physical host, or
reinstall it from scratch. A complete infrastructure has been developed to
install operating system and middleware in a few minutes. To virtualize the
main servers of a data center, a new procedure has been developed to migrate
physical to virtual hosts. The whole Grid data center SNS-PISA is running at
the moment in virtual environment under the high availability system.Comment: 10 page
High availability using virtualization
High availability has always been one of the main problems for a data center.
Till now high availability was achieved by host per host redundancy, a highly
expensive method in terms of hardware and human costs. A new approach to the
problem can be offered by virtualization. Using virtualization, it is possible
to achieve a redundancy system for all the services running on a data center.
This new approach to high availability allows to share the running virtual
machines over the servers up and running, by exploiting the features of the
virtualization layer: start, stop and move virtual machines between physical
hosts. The system (3RC) is based on a finite state machine with hysteresis,
providing the possibility to restart each virtual machine over any physical
host, or reinstall it from scratch. A complete infrastructure has been
developed to install operating system and middleware in a few minutes. To
virtualize the main servers of a data center, a new procedure has been
developed to migrate physical to virtual hosts. The whole Grid data center
SNS-PISA is running at the moment in virtual environment under the high
availability system. As extension of the 3RC architecture, several storage
solutions have been tested to store and centralize all the virtual disks, from
NAS to SAN, to grant data safety and access from everywhere. Exploiting
virtualization and ability to automatically reinstall a host, we provide a sort
of host on-demand, where the action on a virtual machine is performed only when
a disaster occurs.Comment: PhD Thesis in Information Technology Engineering: Electronics,
Computer Science, Telecommunications, pp. 94, University of Pisa [Italy
Design Models for Trusted Communications in Vehicle-to-Everything (V2X) Networks
Intelligent transportation system is one of the main systems which has been developed to achieve safe traffic and efficient transportation. It enables the road entities to establish connections with other road entities and infrastructure units using Vehicle-to-Everything (V2X) communications. To improve the driving experience, various applications are implemented to allow for road entities to share the information among each other. Then, based on the received information, the road entity can make its own decision regarding road safety and guide the driver. However, when these packets are dropped for any reason, it could lead to inaccurate decisions due to lack of enough information. Therefore, the packets should be sent through a trusted communication. The trusted communication includes a trusted link and trusted road entity. Before sending packets, the road entity should assess the link quality and choose the trusted link to ensure the packet delivery. Also, evaluating the neighboring node behavior is essential to obtain trusted communications because some misbehavior nodes may drop the received packets.
As a consequence, two main models are designed to achieve trusted V2X communications. First, a multi-metric Quality of Service (QoS)-balancing relay selection algorithm is proposed to elect the trusted link. Analytic Hierarchy Process (AHP) is applied to evaluate the link based on three metrics, which are channel capacity, link stability and end-to-end delay. Second, a recommendation-based trust model is designed for V2X communication to exclude misbehavior nodes. Based on a comparison between trust-based methods, weighted-sum is chosen in the proposed model. The proposed methods ensure trusted communications by reducing the Packet Dropping Rate (PDR) and increasing the end-to-end delivery packet ratio. In addition, the proposed trust model achieves a very low False Negative Rate (FNR) in comparison with an existing model