word in the query which ranges from 1 to n the current read page of which described by the i th position of the vector pageword is smaller than all the others described in the vector pageword read_pageword reads the successive pages in the file associated with the index i and extracts the triplet site_id page_id relevance check_samepage checks whether the n pages described in the vector pageword coincide if this is the case it returns the boolean value u201c true u201d otherwise it returns the boolean value u201c false u201d read_sitepages reads the number of pages which make up the site specified by the file f_site_pages for implementing the system of indices the search engine is hosted by a redundant server system the operating process being given by the parallelism ensured by the dual core processors which enable several processes to be implemented simultaneously and ensure a high level of stability and efficiency to considerably reduce the risk of denial of service a repeated database system is also provided which besides improving performance has the further advantage of averting the risk of data loss to improve system maintenance and prevent risk of attack a virtual server platform has been used in practice the actual machine hosts different virtual servers which operate on the resources made available by the real machine in this manner possible attacks may block the virtual server but not the physical server which can continue to operate and in the case of failure of the virtual server can automatically restart it the operating system is linux in the fedora distribution the virtualization software is xen developed.