Use the Governor to limit user activity on the XDB Server. The settings you enter for the Governor can affect performance. The more frequently the Governor checks a user's activities, the slower the XDB Server will run. There is a trade-off among frequency of checking, performance, and how long the Governor will wait before terminating a user session.
Every n seconds, the Governor checks the status of the various options against actual server activity. Because the monitoring is not constant, the limits you set could be slightly exceeded before the Governor ends the user session. For example, a user might actually make 104 engine calls before the Governor sees that the user was allowed only 100 engine calls. You can make the Governor more accurate by setting the frequency for checking higher (such as every 10 seconds as opposed to every 30 seconds). However, there is a performance penalty for more frequent checking. See the chapter Server Configuration Utility for information about setting the governor cycle time.