Research And Implementation Of Read Load Balance In Swift

In recent years, with the rapid development of cloud computing technology, cloud storage technology also gets attention and is increasingly applied in the industry. Object cloud storage system Swift, as a kind of cloud storage, becomes the leader in cloud storage system because of the development of its relied platform OpenStack and its excellent characteristics such as scalable architecture, no single point of failure, strong data persistency and so on, and is applied in many occasions. Howerver, Swift use random way to assign servers for requests when it processes read requests, and this will cause servers'load is not even and the rate of processing requests is low. After analysis, this dissertation thought that the causes of such defects mainly include two aspects:the first hand is that Swift doesn't consider servers' readl-time load when assigning requests, and the other hand is that Swift cannot use storage space uniformly. Aiming at the first reason, this dissertation proposed read load balance algorithm based on request process time. Aiming at the second reason, this dissertation proposed storage load balance algorithm based on virtual node. At last, this dissertation designed and realized RB-Swift prototype system which has the read load balance function and verified the system's effectiveness. The specific tasks are as follows:1.By analyzing the process on how Swift deal with clients'read requests deeply, this dissertation found that the low efficiency of request process is attributed to two aspects of shortcomings:not considering server's real-time load and not making use of storage space equablyi. Based on this, aiming at Swift not considering servers' real-time load, this dissertation proposed read load balance algorithm based on request process time, and this algotithm condisers requests' difference, servers' real-time load comprehensively.2.Aiming at Swift cannot make use of storage space evenly, this dissertation proposed storage load balance algorithm based on virtual node. This algorithm considers every virtual node's free space, classify virtual nodes according to free space, and group or merge virtual nodes based on the results of classification. At last, all the objects will be stored in whole storage space uniformly.3.On the basis of read load balance algorithm and storage load balance algorithm above, this dissertatition realized RB-Swift prototype system which has read load balance function. RB-Swift system added preprocess component, requests assign component and virtual node management component based on Swift. At last, this dissertatition verified the RB-Swift's effectiveness.