System with executing nodes for executing schedules

摘要

In a system (1) with storing means (2) for storing schedules (200, 210, 220, 230) and comprising nodes (3-6) for executing the schedules (200, 210, 220, 230), first and second nodes (3, 4) are primary and secondary nodes and comprise checking means (302, 402) for checking the storing means (2) and collecting means (303, 403) for collecting schedules on the node's own initiative. This all is done without the nodes (3, 4) being monitored by a monitoring process of a system supervisor. The different kinds of nodes create a node hierarchy. At least one so-called single point of failure in the form of a monitoring process has been removed. Marking means (304, 404) mark the schedules in the storing means (2). The nodes (3, 4) comprise event driven scheduler (300, 400) for controlling the means (302-304, 402-404). The checking means (302) of the primary node check the storing means (2) a first predefined time-interval ahead of an actual schedule and the checking means (402) of the secondary node check the storing means (2) a second predefined time-interval ahead of an actual schedule, the first predefined time-interval being larger than the second predefined time-interval, to make the primary nodes more privileged than the secondary nodes.