Some mapping rules need to be reported to more than one metric or method. If this is necessary for a large number of mapping rules and methods/metrics the permutations can make it difficult to maintain. An additional mapping rule for each permutation will become unmaintainable.

Problem

mapping rule /api/users/

{id} => method a
mapping rule /api/users/{id}

=> method b
mapping rule /api/users/

{id} => method c
mapping rule /api/groups => method c
mapping rule /api/groups => methods d
mapping rule /api/groups => metric 1

h3. Solution
mapping rule /api/users/{id}

=> method a,b,c
mapping rule /api/groups => methods,c,d & metric 1