The present invention pertains to cloud computing systems and handling of events that occur in the cloud. A correlation system obtains and analyzes various events to obtain comprehensive information about the behavior of the cloud. An event repository receives and maintains time-stamped events, which may be obtained from the cloud itself or from external sources reporting on the cloud. A query engine is employed to select, filter and aggregate events from the event repository. The query engine may take into account metadata which describes relationships between different parts of the cloud. Results from the query engine may be presented on a display or otherwise reported. Using such information, the system may fix known problems or change certain parameters to improve the cloud computing process.