资源重配置算法在系统可存活性中的应用

Application of Resources Reconfiguration Algorithms in System's Survivability

可存活性是用来表明系统在面对蓄意攻击、故障失效或偶发事故时仍能完成其任务的能力。如何提高系统的可存活性是当前安全研究领域的重点。目前提高系统可存活性的方法主要集中在体系结构的设计和资源重配置上。从资源重配置的角度,通过剥夺非关键服务的资源分配给资源受到破坏的关键服务,从而保障关键服务持续运行,实现系统的可存活性。从被剥夺资源的非关键服务尽可能少这一角度出发,利用近似度算法得到一个分配方案;从非关键服务对于关键服务的响应时间尽可能短这一角度考虑,采取时间优先算法得到另一个方案。在近似度算法的实现过程中,同时加入对关键服务响应时间的考虑;在时间优先算法的实现过程中,考虑服务间占有资源的近似度。然后比较两种算法产生的两个方案,选取综合性能较好的一个作为最终的资源分配方案。无论是近似度算法还是时间优先算法,实现容易、时间及空间效率较高、产生的分配方案综合性能较优。

Survivability is the capability of a system to fulfill its mission,in a timely manner,in the presence of attacks, failures, or accidents. How to increase the system＇s survivability is the point research in the realm of security. Presently the method to increasing the survivability is mainly concentrated on the design of system architecture or resource reconfiguration. Based on the view of resource reconfiguration,maintain the critical service running continuously to realize the system＇s survivability, through depriving non-critical services of their resources reconfigured to the critical service. From the point that the number of non-critical services deprived of resources is as small as possible, introduces the ap- proximation degree algorithm（ADA） to get a scheme, and from the point that the time the non-critical services response to the critical is as short as possible, introduces time first algorithm（TFA）to get another scheme. In the procedure of ADA realization,we considered the response time of the non-critical meanwhile, also in the procedure of TFA realiza- tion, we considered the approximation degree of resources between services. Then we compared the two schemes, and chose one which is better in the comprehensive performance as the final scheme. Whether ADA or TFA, the algorithm is easy to realize, efficiency of time and space higher, and the final scheme is better in the over-all performance.