1. A non-transitory computer-readable recording medium having stored therein an event processing control program for event processing that processes received event data in accordance with processing rules and outputs output data, the event processing control program causing a computer to execute a process comprising: obtaining first assessment values pertaining to output data by the event processing for a first type of events, periodically by a first period; calculating a correlation coefficient value of first received event data and second received event data periodically by a second period that is longer than the first period, the first received event data being received event data of the first type and the second received event data being received event data of a second type that is different from the first type of events; comparing the calculated correlation coefficient of the first received event data and the second received event data, and when the calculated correlation coefficient is greater than a threshold value, automatically generating a second filtering condition pertaining to the second received event data, based on a first filtering condition and the correlation coefficient value, the first filtering condition pertaining to the first received data and being specified from the assessment values, wherein at least one of the first filtering condition and the second filtering condition is discarded when the at least one of the first filtering condition and the second filtering condition is beyond a validity period of the at least one of the first filtering condition and the second filtering condition.