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Computer Systems Lab












               be used by cloud gaming developers, cloud service providers,   widely adopted because of its utility in exploiting distributed
               and system researchers for setting up a complete cloud gaming   resources and processing large-scale data. Nevertheless, such
               testbed. GamingAnywhere is the first open cloud gaming test-  promise is diminished somewhat by the difficulty of fitting
               bed to be reported in the literature. We have conducted exten-  streaming data applications into MapReduce. This is because
               sive experiments to quantify the performance and overhead of   MapReduce is limited to the kind of applications in which every
               GamingAnywhere; in addition, we have derived optimal setups   input key-value pair is independent of each other. We plan to
               for system parameters, which in turn allow users to install and   extend the general applicability of MapReduce by enabling de-
               try out GamingAnywhere on their own servers. We expect that   pendence within a set of input key-value pairs. Based on this
               cloud  game  developers,  cloud  service  providers,  system  re-  new model, we shall develop the corresponding methodology
               searchers, and individual users will use GamingAnywhere to set   and software tools capable of processing streaming applica-
               up complete cloud gaming testbeds for different purposes. We   tions.
               firmly believe that the release of GamingAnywhere will stimu-
               late further research innovation in the field of cloud gaming   4. Storage System Designs for Embedded Systems
               systems, or multimedia streaming applications in general.
                                                                    Embedded systems usually utilize flash memory as their stor-
               3. Storage and Processing of Streaming Data in Clouds  age medium. Reduced costs and advances in manufacturing
                                                                    technologies have resulted in the emergence of high-density
               As more and more streaming data applications are moved to   multiple-level-cell and 3D flash memory chips as popular alter-
               Clouds, efficient parallel frameworks and distributed file sys-  natives for embedded applications; however, this has also intro-
               tems are the key to meeting the scalability and performance re-  duced new challenges relating to reliability, performance, and
               quirements for such streaming data applications. Our research   endurance. To this end, we are working on how to adopt heal-
               focuses on the storage and processing of streaming data in   leveling techniques to improve the endurance of 3D flash, and
               Clouds. A critical requirement for the storage of streaming data   are also exploring the possibility of using software solutions
               is the provision of quality-of-service (QoS), which is the ability   to reduce the write disturbance of real 3D flash memory. On
               to guarantee a certain level of performance for an application.   the other hand, we are also investigating the possibility of in-
               We aim to provide QoS in distributed file systems for Clouds,   troducing emerging byte-addressable, non-volatile memories,
               to meet the bandwidth/latency requirement for access to each   e.g., PCM, ReRAM, and STT RAM, into embedded systems. Due
               QoS file, and to improve the overall utilization of storage re-  to their non-volatility and byte-addressability, these emerging
               sources. In the field of text processing, MapReduce has been   non-volatile memories could serve as both working memory
                                                                                   and as a persistent store. Thus, we propose
                                                                                   the concept of a “one-memory system” that
                                                                                   adopts non-volatile memory as both its
                                                                                   main memory and its storage. However, ex-
                                                                                   isting operating systems consider storage
                                                                                   as block devices, and manage main mem-
                                                                                   ory and storage separately. In order to take
                                                                                   advantage of the one-memory architec-
                                                                                   ture, we are redesigning the memory man-
                                                                                   agement and  storage  systems of existing
                                                                                   operating  systems.  At  the  same  time,  we
                                                                                   are investigating new designs to optimize
                                                                                   the storage capacity utilization and mini-
                                                                                   mize redundant storage accesses, in order
                                                                                   to save energy and improve performance.




                Using Virtual Block Remapping to Enhance Data Reliability of 3D Flash Memory.





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