Patent ID: 7287144
Filing Date: 2007-10-23
Classification: G06F

Abstract:
1. A hit ratio estimation device for estimating a hit ratio in a session data cache, in which a Web server sets up said session data cache of preset size for each Web application, reads said session data from said session data cache or a permanent store, depending on whether a cache hit for session data in said session data cache or a cache miss, and refers to or updates an attribute value of read data; wherein, a leave probability as the reciprocal of an average value of the number of data reading sessions per session is defined as p wherein, said Web server mounts one or more counters for counting predetermined count information capable of calculating p wherein, one or more data reading sessions corresponding to one Web page transmission request within the same session are called a group of data reading sessions, and a first data reading session among said group of data reading sessions is called a first reading session of the group of data reading sessions, said hit ratio estimation device estimating the hit ratio ra in said session data cache only for the first reading session of said group of data reading sessions, said hit ratio estimation device comprising: a computational expression setting component adapted to set a computational expression f(a)=a (a on the left side is a substituted for original value, and a on the right is a as new value obtained from the left side computation) including p a true value searching component adapted to search an almost true value of a by the fix point computing method based on said computational expression f(a)=a; and a estimation component adapted to estimate ra based on a searched value of a.