The Research Of Load Balance For DHT Server Cluster System

With the rapid development of Internet, the network bandwidth and data processing requirements are also increasing. To solving this problem, the DHT (Distributed Hash Table) server cluster technology is getting everyone's attention. Now this technology has been used in many scenarios, such as P2PSIP server clusters, distributed IMS system and DSN system. In the DHT server cluster system, there are also the load balacing problems. DHT network often has O(log N) of the load imbalance degree. Traditional load balancing algorithms do not take full account of the particularity of DHT server clusters, and they just can achieve limited load balancing. This paper proposes a load balancing schem for DHT server cluster. Compared to traditional methods, this scheme can achieve better load balancing, and needs a smaller overhead.The main work includes the following components:1,Proposed novel virtual node load balancing scheme, which can reduce route maintenance overhead. In the traditional program, each physical node will maintain V copies of the routing table and the neighbor node list. This paper separates the two funcitions of routing maintenance and data storage. Through this improvement, each node in the system only needs to maintain a single routing table and neighbor table. It greately reduces the overhead of routing maintenance.2,The virtual ID specified generation scheme been proposed to achieve better load balancing. Compared to the traditional program of randomly generated virtual ID, our scheme generates the virtual ID in a more purposeful and more focused idea. The simulation shows that our algorithm is much better than the traditional method, it has better load balancing, and has less transfer costs when the node leaves the network.3,Achieve the DHT cluster system BLESS, and test the performance of load balancing algorithms. The overall structure of the BLESS system, the designs of key modules will be introduced in this paper. The virtual ID specified generation algorithm and random generation algorithms are tested in BLESS system. The result is similar to the simulation result.In summary, this paper proposes a novel load balancing scheme for DHT server cluster. The scheme can achieve good load balancing degree, and has less cost, compared to the traditional algorithms. In this paper, we use both of simulation and implementation to validate the availability and reliability of the algorithms.