Notifies this listener that the specified {@code node}'s health has been updated. The node's health can be obtained by calling {@link Node#getHealth getHealth} on the node status information object.Note that the node's health may not have changed since the last update.
On node startup a health update will be made to indicate the initial health of the node.
Once a node has failed, i.e. {@link Node#isAlive() node.isAlive()}returns {@code false}, the node's health will not change.
@param node node status information