Described are techniques for controlling a flow of I/O requests. R is received denoting a current maximum number of outstanding I/O requests allowed to be issued by a first data storage system to a second data storage system over a path. Assessment processing is performed to obtain a first performance value, a second performance value, and a third performance value, respectively, when the maximum number of outstanding I/O requests allowed to be issued by the first data storage system to the second data storage system over the path is R+delta1, R, and R−delta2 (delta1 and delta 2 are positive integer values). It is determined whether to update R in accordance with criteria including the first performance value, the second performance value and the third performance value.