Web search engines retrieve a vast amount of information for a given search query. But the user needs only trustworthy and high-quality information from this vast retrieved data. The response time of the search engine must be a minimum value in order to satisfy the user. An optimum level of response time should be maintained even when the system is overloaded. This paper proposes an optimal Load Shedding algorithm which is used to handle overload conditions in real-time data stream applications and is adapted to the Information Retrieval System of a web search engine. Experiment results show that the proposed algorithm enables a web search engine to provide trustworthy search results to the user within an optimum response time, even during overload conditions.