1. A log analysis system comprising: a first processor unit configured to append common information to analysis target information generated by events; the processor unit being configured to make information granularities uniform based on the contents of the analysis target information and the common information to output analysis unit information; and a second processor unit configured to integrate the analysis unit information output from the first processor unit to generate detection target event candidates, the second processor unit being configured to determine whether or not the events have at least one specific quality, the events having generated the analysis target information specified by the detection target event candidates.