隨著科技的蓬勃發展,現今的網路應用服務迅速增加。近年來十分熱門的雲端運算將是提供快速服務的一大趨勢,它是一個包含龐大的異質處理單元、記憶體和高速網路的分散式運算環境,並透過網路來為人們提供服務。因此,在各種異質性節點和應用服務下,如何提供最合適及快速的服務,將是排程演算法的一大考驗。 然而,先前學者所提出許多演算法,如Min-Min、Max-Min和Sufferage等,都不適應於異質性雲端運算環境。主要是因為Min-Min及Max-Min只考慮了單一節點能力,而未考慮節點間的負載平衡,進而無法降低任務完成時間,而Sufferage雖然改善了工作負載不均的問題,但仍於任務預估完成時間差距大的情況下,將無法降低任務完成時間。 所以,本研究將針對異質性雲端運算環境,以所提出的ClusterMaxSufferage(CMS)演算法來改善傳統演算法的缺點,進而降低任務完成時間及實現系統之負載平衡,以提昇整體系統之效能及可用性。但因為CMS演算法會優先分配較大的任務,而未考慮其他節點能力,造成任務分配到較差的節點,使任務的完成時間增加。因此我們再提出ClusterMaxSufferage+ (CMS+)來改善先前的演算法之缺點,進而降低任務完成時間及達到系統之負載平衡。
With the exploded development of technology, the applications of network services increase more and more. Cloud providers need a system to provide quick network service, thus the cloud computing is proposed in recent years. The cloud computing system is consists of a huge number of heterogeneous nodes, memories, high-speed networks, and various application services to provide a lot of service over the Internet for users. However, how to provide the suitable and fast service among a huge heterogeneous service node is an important issue. Therefore, the previous studies proposes many algorithms, such as Min-min, Max-min, and Sufferage algorithms cannot adapt to existing heterogeneous cloud computing environment. It is because that the Min-min and Max-Min algorithms have high makespan and workload in a high heterogeneous environment. In Sufferage algorithm, the workload of each service node can be improved to achieve load balance of system. But, it cost high makespan in a heterogeneous task environment. As a result, we proposes a ClusterMaxSufferage (CMS) algorithm base on Sufferage heuristic to improve the performance of system and achieve load balance in a heterogeneous cloud computing environments. However, the a larger tasks will be assigned in CMS algorithm first without estimate the ability of other nodes. Therefore, the task is easy to assign to a poor node to increase the task of completion time. As a result, we proposes ClusterMaxSufferage+ (CMS+) algorithm again to improve the CMS to reduce the task of completion time and the achieve load balance.