[syslog-ng] Analysis of logs and alerting

Hi, I am implementing a syslog-ng centralized correlation server. The server receives the log entries from some servers, apps and devices. Is there any good product (commercial or open-source) with GUI or web interface to analyze these logs and give real time alerts with strong data mining tools? I need a tool which could be used by both help desk non-technical staff and technical engineers. It should give basic alerting on applications' or devices' failures first for help desk, and then engineers could dig deeper into these alerts to understand the problem. Kind regards