Best Practices for Web Traffic Sorting

I have been reading through forum topics sorting examples trying to figure out the best way for our company to approach web traffic sorting. We have some PHP, some Java and some Cold Fusion code in separate server pools.

 

 

We would like to sort web traffic to them based on a predictable convention rather than per application since we have well over 100 out there. The approach should not be too complicated but allow for legacy application links, (primarily in cold fusion), to continue to function. Are there any Best Practices out there for this type of situation? That is, what is everyone else doing to keep heterogeneous web applications cooperating?

 

 

Sorting on extensions such as .cfm or .php will not help us since there are several links out there to directories, (rather than individual files) and resources such as images with different extensions that need to find their way.

 

 

Thank you in advance for feedback,

 

 

-P