Abstract:
Proxy server is a dedicated server to cache Internet objects, requested from clients. If the object does not exist in the proxy server, it will retrieve that object from the original server. Every time a client access to the Internet, it has to access through a proxy server. Therefore the server has to be reliable and available.
This thesis proposes an approach to improve the reliability of proxy system by using the idea of redundant server. The additional server and program are added without any change to old software system.
There are two levels of failure protection, hardware level and software level. To accommodate hardware reliability, additional server is added. Therefore, when a failure occurs at one server, another server can continue to operate without an interruption. At the software level, the additional program modules are added in order to reactivate dead cache process once detected. Also, a synchronization program is added in order to make sure the caches content between both servers are identical.
Experimental results in this study have shown that, the cache contents of both servers are synchronized during normal operation and after recovery process is performed after cache failures. Moreover, the reliability of the proposed system improved while the hit rates and userà à à à ¢ s response time is maintained.
