Today’s online applications consist of middleware units (such as databases, web servers, etc.) working together with application software. These units as well as the operating system they run on continuously generate records to mirror their statuses. Collecting and aggregating these records at a central point for real-time examination, analysis and rule-based alert generation is a crucial task in monitoring the health of such component-based systems. Receiving instant notifications in error conditions, and examining the sequence of events at varying levels of detail in order to determine the root cause is necessary to assure the smooth operation of the system and for resolution of errors in a way that has the least impact on customers. The ZettaLogs system is designed as a cloud-based log management service to achieve the above objectives. Users register to use the service from the web interface and request the logs they are interested in from the ZettaLogs service. The system maintains records for a retrospective period and provides users with the necessary infrastructure and interfaces to analyze their records in real time.