The Monitoring and Control System of the LHCb Event Filter Farm

The LHCb experiment at CERN will have an on-line trigger farm composed of up to 2000 PCs. In order to monitor and control each PC and to supervise the overall status of the farm, a farm monitoring and control system (FMC) was developed. The FMC is based on distributed information management (DIM) system as network communication layer, it is accessible both through a command line interface and through the Prozeszligvisualisierungs und Steuerungssystem (PVSS) graphical interface, and it is interfaced to the finite state machine (FSM) of the LHCb experiment control system (ECS) in order to manage anomalous farm conditions. The FMC is an integral part of the ECS, which is in charge of monitoring and controlling all on-line components; it uses the same tools (DIM, PVSS, FSM, etc.) to guarantee its complete integration and a coherent look and feel throughout the whole control system.