Wednesday, May 10, 2017

Queueing theory based modeling and optimal scheduling in Map-Reduce-like Frameworks

FORK-JOIN QUEUE MODELING AND OPTIMAL SCHEDULING IN PARALLEL PROGRAMMING FRAMEWORKS

ABSTRACT
MapReduce framework is widely used to parallelize batch jobs since it exploits a high degree of multi-tasking to process them. However, it has been observed that when the number of servers increases, the map phase can take much longer than expected. This thesis analytically shows that the stochastic behavior of the servers has a negative effect on the completion time of a MapReduce job, and continuously increasing the number of servers without accurate scheduling can degrade the overall performance. We analytically model the map phase in terms of hardware, system, and application parameters to capture the effects of stragglers on the performance. Mean sojourn time (MST), the time needed to sync the completed tasks at a reducer, is introduced as a performance metric and mathematically formulated. Following that, we stochastically investigate the optimal task scheduling which leads to an equilibrium property in a datacenter with different types of servers. Our experimental results show the performance of the different types of schedulers targeting MapReduce applications. We also show that, in the case of mixed deterministic and stochastic schedulers, there is an optimal scheduler that can always achieve the lowest MST.

KEYWORDS

Tuesday, May 09, 2017

FORK-JOIN QUEUE MODELING AND OPTIMAL SCHEDULING IN PARALLEL PROGRAMMING FRAMEWORKS

ABSTRACT
MapReduce framework is widely used to parallelize batch jobs since it exploits a high degree of multi-tasking to process them. However, it has been observed that when the number of servers increases, the map phase can take much longer than expected. This thesis analytically shows that the stochastic behavior of the servers has a negative effect on the completion time of a MapReduce job, and continuously increasing the number of servers without accurate scheduling can degrade the overall performance. We analytically model the map phase in terms of hardware, system, and application parameters to capture the effects of stragglers on the performance. Mean sojourn time (MST), the time needed to sync the completed tasks at a reducer, is introduced as a performance metric and mathematically formulated. Following that, we stochastically investigate the optimal task scheduling which leads to an equilibrium property in a datacenter with different types of servers. Our experimental results show the performance of the different types of schedulers targeting MapReduce applications. We also show that, in the case of mixed deterministic and stochastic schedulers, there is an optimal scheduler that can always achieve the lowest MST.

KEYWORDS
Stochastic processes, Computational model, Delayed Tailed Distribution, Optimal scheduling, Cloud computing, Synchronization, Queuing Theory, MapReduce, Stochastic Modeling, Performance Evaluation, Fork-Join Queue.

Thursday, April 27, 2017

Farshid Farhat 's Site @ PSU

Farshid Farhat 's Site @ PSU

Publications

  • Security Weaknesses in PGP Protocol, F Farhat, M Heydari, MR Aref, 2013.

Thursday, August 25, 2016

Diman Zad Tootaghaj 's publications


  1. 1.D. Z. Tootaghaj, F. Farhat. Optimal placement of Cores, Caches and Memory controllers in NoC. arXiv, 2016. [link] [pdf]
  2. 2.F. Farhat, D. Z. Tootaghaj, M. Arjomand. Towards optimizing data computing in the cloud. arXiv, 2016. [link] [pdf]
  3. 3. F. Farhat, D. Z. Tootaghaj, Y. He, A. Sivasubramaniam, M. T. Kandemir, C. R. Das. Stochastic modeling and optimization of stragglers. IEEE transaction on Cloud Computing (TCC), 2016. [link] [pdf]
  4. 4.D. Z. Tootaghaj,  Evaluating cloud workload characteritics. Master’s thesis, The Pennsylvania State University, 2015. [link] [pdf]
  5. 5.D. Z. Tootaghaj, F. Farhat, M. Arjomand, P. Faraboschi, M. T. Kandemir, A. Sivasubramaniam, C. R. Das, Evaluating the Combined Impact of Datacenter Architecture and Cloud Workload Characteristics on Performance, Network Traffic and Cost, IEEE International Symposium on Workload Characterization (IISWC) 2015. [link] [pdf]
  6. 6.F. Farhat, D. Z. Tootaghaj, A. Sivasubramaniam, M. T. Kandemir, C. R. Das, Modeling and Optimization of Straggling Mappers.Technical Report CSE-14-006, Pennsylvania State University. [link] [pdf]
7. D. Z. Tootaghaj, F. Farhat, M. R. Pakravan, M. R. Aref, Risk of Attack Coefficient Effect on Availability of Ad-hoc Networks, IEEE CCNC Research Student Workshop, 2011. [link] [pdf]
8. D. Z. Tootaghaj, F. Farhat, M. R. Pakravan, M. R. Aref, Game-Theoretic Approach to Mitigate Packet Dropping in Wireless Ad-hoc Networks, IEEE CCNC Research Student Workshop, 2011. [link] [pdf]
9. M. A. Kashiha, D. Z. Tootaghaj, Partial Discharge Source Classification and De-noising in Rotating Machines Using Discrete Wavelet Transform and Directional Coupling Capacitor, Journal of Electromagnetic Analysis and Applications and submitted and accepted to Asia-Pacific Power and Engineering Conference (APPEEC), sponsored by IEEE Power & Energy Society (PES), March 2009. [link] [pdf]

Towards Stochastically Optimizing Data Computing Flows

Optimal Placement of Cores Caches and MemoryControllers in NoC

Monday, June 13, 2016

تحليل پنهان سازي تصوير با نرخ درج پايين در حوزه مكان فرحت، فرشيد Farhat, Farshid

  1. شماره پایان نامه:45945
  2. کد دانشکده:05
  3. پديدآور:فرحت، فرشيد
  4. عنوان:تحليل پنهان سازي تصوير با نرخ درج پايين در حوزه مكان.
  5. نام دانشگاه/پژوهشگاه:صنعتي شريف
  6. سال اخذ مدرك:1392.
  7. نام دانشکده:مهندسي برق
  8. مقطع:دكتري
  9. گرایش:مخابرات سيستم
  10. توصیف ظاهری:89ص.: جدول، نمودار، كتابنامه؛ چكيده به فارسي و انگليسي
  11. توصیفگر:نهان نگاري تصويرImage Watermarking
  12. توصیفگر:تحليل نهان نگاريSteganalysis
  13. توصیفگر:تجزيه مقادير ويژهEigenvalue Decomposition
  14. توصیفگر:جاسازي كم ارزش ترين بيتLeast Significant Bit (LSB)Embedding
  15. توصیفگر:خودهمبستگي نسبيRelative Autocorrelation
  16. توصیفگر:مجموع كمترين جزء هاParts Min Sum
  17. توصیفگر:تخمين نرخ جاسازيEmbedding Rate Estimation
  18. توصیفگر:مجموع درگاشت هاي محليLocal Entropies Sum
  19. استاد راهنما.قائم مقامي، شاهرخ
  20. استاد مشاور.عارف، محمد رضا

ارتقاء امنيت پروتكل هاي مسيريابي در شبكه هاي اقتضايي (فرشيد فرحت)

  1. شماره پایان نامه:37533
  2. کد دانشکده:05
  3. پديدآور:فرحت، فرشيد.
  4. عنوان:ارتقاء امنيت پروتكل هاي مسيريابي در شبكه هاي اقتضايي.
  5. نام دانشگاه/پژوهشگاه:صنعتي شريف
  6. سال اخذ مدرك:1386
  7. نام دانشکده:مهندسي برق
  8. گرایش:كارشناسي ارشد (مخابرات رمز)
  9. یادداشت:100ص0: جدول، نمودار، كتابنامه؛ چكيده به فارسي و انگليسي
  10. توصیفگر:رمزنگاريCRYPTOGRAPHY
  11. توصیفگر:امنيتSecurity
  12. توصیفگر:شبكه خودجوشAd Hoc Network
  13. توصیفگر:قرارداد مسيريابيRouting Protocol
  14. توصیفگر:الگوريتم رمز قالبي كليد متقارنSymmetric-Key Block Cipher
  15. توصیفگر:حمله لانه كرميWormhole Attack
  16. توصیفگر:شبيه ساز MANETMANET Simulator
  17. استاد راهنما.عارف، محمد رضا،
  18. استاد راهنما.سلماسي زاده، محمود،