1. A method for monitoring elements of a distributed computing system, the method comprising: evaluating a metric event from a monitored element based on at least one of tags and conditions of the monitored element by applying declared group functions corresponding to declared groups over the metric event; and at least one of admitting the monitored element into membership of a declared group, evicting the monitored element from membership of a declared group, and maintaining membership of the monitored element in a declared group based on the evaluation of the metric event.