ELFms monitoring system (LEMON)

Lemon is a server/client based monitoring system. On every monitored node, a monitoring agent launches and communicates using a push/pull protocol with sensors which are responsible for retrieving monitoring information. The extracted samples are stored on a local cache and forwarded to a central Measurement Repository. Sensors can collect information on behalf of remote entities like switches or power supplies. The Measurement Repository can interface to a relational database or a flat-file backend for storing the received samples, and can be queries via a SOAP based API.

• http://cern.ch/lemon

Lemon consists of several parts and depending on your need you may install only a certain part of it. The components are:

• Lemon client - contains sensors and sensor agent
• Lemon server - depending on your choice you can install either flat file based or Oracle based server. They slightly differ in functionality. Oracle based installation offers more full featured system. On the other hand requires some knowledge on the Oracle administration/ or help from a DBA.
• Web interface - this includes caching system for the data as well as direct access to the data repository. In case you want to use flat file repository to the server, it is needed that you install the web interface on the same machine (or have data directories exported to the machine where your web server will run).