Network virtualization is a promising way to overcome the current ossification of the Intemet. It is essential challenge to find effective, efficient and robust embedding algorithms for recovering virtual network. The...Network virtualization is a promising way to overcome the current ossification of the Intemet. It is essential challenge to find effective, efficient and robust embedding algorithms for recovering virtual network. The virtual network mapping algorithm based on integer programming which was proposed months ago. But it did consider the faults of physical network resources, which is so called survivable virtual network embedding （VNE） problem. Previous strategies for enabling survivability in network virtualization focused on providing protection for the physical network or enhancing the virtual networks by providing backup physical resources in advance, and treated all the physical failures as link failures. In the article, a dynamic recovery method is proposed to solve the survivable virtual network embedding problem based on the integer programming VNE algorithm. The dynamic recovery method doesn＇t need to backup physical resources and it makes more substrate resources which can be used in the embedding. The dynamic recovery process will be activated only when physical failures occur. Different algorithms are used to recovery node and link failures. Simulations show that the method helps to recover almost all of physical failures by finding the substitute nodes and paths, and its performance is very close to that of pure VNE method without considering physical failures.展开更多
In the web context, there is an urgent need for a self-healing database system which has the ability to automatically locate and undo a set of transactions that are corrupted by malicious attacks. The metrics of survi...In the web context, there is an urgent need for a self-healing database system which has the ability to automatically locate and undo a set of transactions that are corrupted by malicious attacks. The metrics of survivability and availability require a database to provide continuous services during the period of recovery, which is referred to as dynamic recovery. In this paper, we present that an extended read operation from a corrupted data would cause damage spreading. We build a fine grained transaction log to record the extended read and write operations while user transactions are processing. Based on that, we propose a dynamic recovery system to implement the damage repair. The system captures damage spreading caused by extended read-write dependency between transactions. It also retains the execution results for blind write transactions and gives a solution to the issues of recovery conflicts caused by forward recovery. Moreover, a confinement activity is imposed on the in-repairing data to prevent a further damage propagation while the data recovery is processing. The performance evaluation in our experiments shows that the system is reliable and highly efficient.展开更多
基金supported by the National Basic Research Programs of China(2012CB315801)
文摘Network virtualization is a promising way to overcome the current ossification of the Intemet. It is essential challenge to find effective, efficient and robust embedding algorithms for recovering virtual network. The virtual network mapping algorithm based on integer programming which was proposed months ago. But it did consider the faults of physical network resources, which is so called survivable virtual network embedding （VNE） problem. Previous strategies for enabling survivability in network virtualization focused on providing protection for the physical network or enhancing the virtual networks by providing backup physical resources in advance, and treated all the physical failures as link failures. In the article, a dynamic recovery method is proposed to solve the survivable virtual network embedding problem based on the integer programming VNE algorithm. The dynamic recovery method doesn＇t need to backup physical resources and it makes more substrate resources which can be used in the embedding. The dynamic recovery process will be activated only when physical failures occur. Different algorithms are used to recovery node and link failures. Simulations show that the method helps to recover almost all of physical failures by finding the substitute nodes and paths, and its performance is very close to that of pure VNE method without considering physical failures.
基金Supported by the National Hi-Tech Research and Development 863 program of China under Grant No. 2006AA01Z430
文摘In the web context, there is an urgent need for a self-healing database system which has the ability to automatically locate and undo a set of transactions that are corrupted by malicious attacks. The metrics of survivability and availability require a database to provide continuous services during the period of recovery, which is referred to as dynamic recovery. In this paper, we present that an extended read operation from a corrupted data would cause damage spreading. We build a fine grained transaction log to record the extended read and write operations while user transactions are processing. Based on that, we propose a dynamic recovery system to implement the damage repair. The system captures damage spreading caused by extended read-write dependency between transactions. It also retains the execution results for blind write transactions and gives a solution to the issues of recovery conflicts caused by forward recovery. Moreover, a confinement activity is imposed on the in-repairing data to prevent a further damage propagation while the data recovery is processing. The performance evaluation in our experiments shows that the system is reliable and highly efficient.
