= Node Handler = The nodehandler is the central experiment controller. A central '''NodeHandler''' process communicates with '''NodeAgents''', one on each active node in the testbed. The '''NodeHandler''' is hosted on one of the testbed's utility servers. Applications are loaded and executed by a '''NodeAgent''' on instructions from the '''NodeHandler'''. These instructions will also include the initial property settings for the applications. In addition to providing interfaces for experiment execution, nodehandler also provides the following built in applications: * [wiki:Internal/Infrastructure/OMF/NodeHandler/Applications/LoadNode load] - Install a given disk image on the nodes in a testbed * [wiki:Internal/Infrastructure/OMF/NodeHandler/Applications/SaveNode save] - Saving node image * [wiki:Internal/Infrastructure/OMF/NodeHandler/Applications/TellNode tell] - Switch ON/OFF the nodes in a testbed? * [wiki:Internal/Infrastructure/OMF/NodeHandler/Applications/StatNode stat] - Returns the status of the nodes in a testbed?