A reconnection system re-forms a control tree for an application that is executed in parallel without terminating execution of the application. The reconnection system detects when a node of a control tree has failed and directs the nodes that have not failed to reconnect to effect the re-forming of the control tree without the failed node and without terminating the application. Upon being directed to reconnect, a node identifies new child nodes that are to be its child nodes in the re-formed control tree. The node maintains the existing connection with each of its current child nodes that is also a new child node, terminates the existing connection with each of its current child nodes that is not also a new child node, establishes a new connection with any new child node that is not a current child node, and directs each new child node to reconnect.