The Process Manager in the ATLAS DAQ System

This paper describes the process manager in the ATLAS DAQ system. The purpose of the process manager is to perform basic process control on behalf of the software components of the DAQ system. It is able to create, destroy and monitor the basic status (e.g., running, exited, killed) of software components on the DAQ workstations and front-end processors. Section I gives a brief overview of the process manager functionalities. Section II focuses on the requirements the process manager system has to fulfil to be fully integrated in the DAQ system. Section III shows how the requirements are met by the current implementation. The communication schema between the different parts of the process manager system, the procedure to launch a process and the possible states in which a process can be are described in Sections IV, V and VI. Section VII deals with some consideration of the process manager performance while some conclusions are given in Section VIII.