1. A computer-implemented method for displaying performance data for a computing environment, the method comprising: determining values for a performance metric for a plurality of entities that comprise the computing environment; and displaying the computing environment as a tree comprising nodes representing the plurality of entities and edges representing parent-child relationships between the plurality of entities; wherein while displaying each leaf node in the tree, the method comprises: comparing the values of the performance metric against one or more state-specific threshold values to determine the performance states for the leaf node; and displaying the leaf node as a shape comprising an indicator for a performance state associated with the leaf node; wherein while displaying each parent node in the tree, the method comprises: determining counts of each of one or more performance states associated with every leaf nodes under the parent node; displaying the parent node as an outer ring and an inner circular shape surrounded by the outer ring, wherein the outer ring comprises visually distinct sections associated with each of the one or more ring performance states, wherein the visually distinct sections are sized proportionately with the determined counts for each of the associated performance states; and displaying an identifier for a type of entity that is represented by the parent node, and an indicator of the performance state of the parent node within the inner circular shape, wherein the performance state is determined based on a worst performance state of any child node under the parent node; and wherein while displaying a set of child nodes for each parent node, the method comprises: determining a performance state for each child node in the set based on a value of the performance metric for an entity associated with the child node, wherein a set of possible performance states vary in severity; wherein if a child node in the set has descendants in the tree, the performance state for the child node includes counts of performance states for the descendants of the child node, and determining a sorted order for the set of child nodes based on counts of descendents of the child nodes having a most-severe performance state; and displaying the set of child nodes in the sorted order.