  Cloud computing facilitates the access of applications and data from any
location by a distributed storage system. Erasure codes offer better data
replication technique with reduced storage costs for more reliability. This
paper considers the erasure-coded data center with multiple servers in a
wireless network where each is equipped with a base-station. The cause of
latency in the file retrieval process is mainly due to queuing delays at each
server. This work puts forth a stochastic optimization framework for obtaining
the optimal scheduling policy that maximizes users' quality of service (QoS)
while adhering to the latency requirements. We further show that the problem
has non-linear functions of expectations in objective and constraints and is
impossible to solve with traditional SGD like algorithms. We propose a new
algorithm that addresses compositional structure in the problem. Further, we
show that the proposed algorithm achieves a faster convergence rate than the
best-known results. Finally, we test the efficacy of the proposed method in a
simulated environment.
