Here , I have a condition such that my upper system sending multiple request with username and password.My job is validate the user name and password with lower system and send response back to upper system. The difficulty is lower system is very slow and no able to handle load of incoming requests so, I have to build logic to get request from upper system , then check user name and password make an condition if incoming username and password has send for validation to lower system then hold that request for all incoming requests at my end then after the response from lower system send response to all incoming request (has same user name and password ) .

can you please help me to build the logic ?

Thanks in advance !!!!