Research And Implementation Of Cache Mechanism In Web Application Services

With the rapid development of Internet and browser technology continuously improves, Web has become the primary platform for users to retrieve and post information. However, with the increase of user access, the Web server is slowing down without the ability to response users’request immediately. To solve this problem, a lot of new technologies had been proposed. The caching mechanism is considered to be one of the most effective methods to improve the response time of the Web service without changing the original architecture of the Web service. So the caching mechanism is important to know. Our work will deep into the caching mechanism from every side of web service under the Multimedia Conference System. The main work includes:At the beginning of the work, we analyze the HTTP protocol header fields associated with the cache, theory and implementation of Web services static cache technology.Then we design and implement a new caching system based on LRU replacement strategy by analyzing the popular cache replacement policies and taking advantage of multimedia conferencing data characteristics. The system includes four major functional modules:Cache Manager, Cache Replacement Policy Module, Cache Listener and Cache Data Storage Module. In Cache Replacement Policy Module, We propose an LRU replacement policy which effectively increases the byte hit rate compared with original replacement policy. In the Data Storage Module, we propose a labeling algorithm which can effectively improve memory utilization and reduce memory fragmentation. With these technologies, we improve the cache system response time significantly.In our work, we also propose a Memcached based solution to solve the problem that the session cannot be shared in distributed environment. We deploy the Memcached service in Hibernate framework to achieve the database caching which improves access throughput and service response time.Finally, we apply the caching system into multimedia conferencing system with a full functional experiment. The results prove that our caching system has a higher byte hit ratio, memory utilization and faster response over the original one. The caching system greatly improves the performance of multimedia conferencing system.