Simplified support of an isolated computer network

The invention concerns a method, a device and computer program products product for allowing performance related data to be obtained from an isolated computer network that includes a diagnostics collection function. According to the present invention selections from a support user of nodes (16) and plug-in modules (18) associated with applications provided in the isolated computer network that are to be diagnosed are received (30) by a autocollector file generating unit, which then provides (34) at least one command file with instructions for the diagnostics collection function, including the user selected nodes and plug-in modules, and saves (38) the provided data as an autocollector file (ACF) that automatically makes the diagnostics collection function to apply the command file on the nodes and plug in modules when being activated.