To help administrators optimize their query service, the system provides a number of different performance monitors. These monitors measure criteria such as the number of documents that need to be indexed and how fast queries are being processed. The system was designed to require little, if any, maintenance. Once Index Server is set up, all operations are automatic, including updates, index creation, optimization, and even crash recovery if there is a power failure. Index Server was designed from the start to work in mission-critical environments where the server must be running 24 hours a day, 7 days a week.