Joint CLEEN and ACROSS Workshop on Cloud Technology and Energy Efficiency in Mobile Communications Non-Cooperative Computation Offloading in Mobile Cloud Computing Valeria Cardellini University of Roma Tor Vergata, Italy Joint work with: V. De Nitto Personè, V. Di Valerio, F. Facchinei, V. Grassi, F. Lo Presti, V. Piccialli
Computation offloading n Mobile devices have limited computing and processing capabilities Battery life! n Old idea: offload computation to some surrogate server (cyber foraging) n Mobile-cloud convergence n Increasing number of latency-sensitive, compute-intensive and memory-intensive applications on mobile devices Wearable cognitive assistance, edge analytics in IoT, automotive environments, Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 2
Cloud- based augmenta0on of mobile devices n Resource- limited mobile devices can overcome their limita0ons by offloading opera0ons to more powerful servers Either proximate, i.e. single hop (cloudlet) or mul0- hop (cloud data center) Wireless AP Mobile devices Cloudlet Distant cloud servers on Internet Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 3
Cloudlet n Self- managed data center with soc state and located at the network edge Consistent with Fog compu0ng ( Fog is the cloud close to the ground ) and micro cloud concepts n Example of cloudlet infrastructure and socware Cloudlet- specific extensions to OpenStack (by Satya at CMU) Nokia LTE base sta0on with cloudlet- like hos0ng infrastructure Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 4
Three- 0er architecture n Hybrid three- 0er architecture for mobile- cloud convergence Local 0er: mobile nodes Middle 0er: energy- unlimited but resource- limited nearby cloudlets within one wireless hop of mobile devices Remote 0er: resourceful distant cloud servers n Where to offload? How to get the benefits of external servers for offloading while limi0ng latency issues of distant servers and considering energy constraints of mobile devices Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 5
Our proposal n Non- coopera0ve game theore0c approach to analyze and manage the computa0on offloading strategy Unmanaged usage scenario: no central authority Mul0ple non- coopera0ve mobile devices share the cloudlet limited compu0ng resources Mobile devices can send their computa0ons to any of the three 0ers V. Cardellini, V. De NiTo Personè, V. Di Valerio, F. Facchinei, V. Grassi, F. Lo Pres0, V. Picciali, A game- theore0c approach to computa0on offloading in mobile cloud compu0ng, Mathema5cal Programming, available online, Apr. 2015. Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 6
Our goal n Determine whether and where to offload a task based on the impact this has on the user experience, expressed through QoS measures Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 7
System model n Standard queueing theory for system model To capture the effects of computa0on offloading (i.e., task conten0on on shared resources) on users perceived performance Focus on task response 0me 8
Problem formula0on n To determine the op0mal strategy, each user needs to solve: n Problem formula0on: generalized Nash equilibrium problem (GNEP) Both the players objec0ve func0ons and the strategy sets depend on the other players strategies Jointly convex game (common linear constraint) 9
GNEP proper0es and distributed algorithm n Game can be solved by finding a solu0on to a suitable Varia0onal Inequality We show equilibrium existence and monotonicity proper0es of the GNEP n Distributed algorithm for compu0ng an equilibrium strategy for each mobile user n Its design required us: To analyze in- depth the underlying equilibrium problem To apply some very recent algorithmic developments n Appealing for real- world implementa0on Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 10
Distributed algorithm n Synchronous and itera0ve Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 11
Numerical results cloudlet cloudlet cloud mobile mobile cloud Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 12
Numerical results cloudlet mobile cloud cloudlet n Price of anarchy Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 13
Prototype architecture n Working prototype based on offloading middleware Offloading at method granularity Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 14
Prototype addi0onal features n Adapta0on capabili0es based on MAPE cycle n Discovery and deployment of offloading service Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 15
Prototype results: face recogni0on Cloud server: AWS EC2 m3.xlarge Cloud server: AWS EC2 m3.2xlarge Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 16
Conclusions n Non- coopera0ve usage scenario for computa0on offloading in a three- 0er architecture Users try to take advantage selfishly of the available cloudlet resources Solu0on with solid theore0cal founda0on and appealing for real- world implementa0on Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 17
Future work n Possible extension of our proposal Remove limita0on on user generated load (cannot exceed the mobile device capacity) Consider mul0ple class model of tasks launched by users Include monetary cost n More general challenges Use cloudlets to improve reliability Consider mul0ple (possibly coopera0ve) cloudlets Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 18
That s All Folks! Thank you for the aten0on cardellini@ing.uniroma2.it htp://www.ce.uniroma2.it/~valeria Non-Cooperative Computation Offloading in Mobile Cloud Computing @EUCNC'15 Workshop 1, June 29 2015 19