School of ICS

    Khanh Nguyen

I am a PhD candidate in Computer Science Department at UCI, working under my advisor, Prof. Guoqing (Harry) Xu.
I am a recipient of the 2017 Google PhD Fellowship in Systems and Networking. I am also a 2017 Facebook Fellowship Finalist (among the top 5% of 800+ applicants world-wide).
My research aims to develop practical techniques to solve scalability issues in Big Data systems.
Specifically, I am interested in developing programming language extensions, compiler and runtime supports to improve system performance including efficiency, scalability, and latency.
I earned my MS('15) and BS('12) in Computer Science from UCI. Prior to this, I earned my AA('10) in Mathematics and AS('10) in Computer Science from Fullerton College.

I mentored several summer interns in our research group:

  • John Thorpe and Tim Nguyen (2016, UCI undergraduates)
  • Sung-Soo Son and HanSem Jeon (2016, UCI I-SURF Fellows from Kookmin University, South Korea)
  • Emily Hu (2016, from Northwood high school, now at UC Berkeley)
  • Lawrence Xu (2016, from University high school, now at Purdue)
  • Yoonseung Choi and Soyeong Park (2015, UCI I-SURF Fellows from Kookmin University, South Korea)
  • Ankur Gupta (2014, from University high school, now at UCSD)
  • Wendy Wei (2013, from University high school, now at MIT)
  • Allen Min and Jonathon Tsai (2012, from Gretchen A. Whitney high school, graduated UCI'17)

My current CV can be found here
My research summary can be found here

  • Khanh Nguyen, Lu Fang, Guoqing Xu, Brian Demsky, Shan Lu, Sanazsadat Alamian, and Onur Mutlu. "Yak: A High-Performance Big-Data-Friendly Garbage Collector", the 12th USENIX Symposium on Operating Systems Design and Implementation (OSDI), Savannah, GA, November 2-4, 2016. (Acceptance rate: 47/267, 18%) [PDF] [PDF Slides] [Slides]
  • Khanh Nguyen, Lu Fang, Guoqing Xu, and Brian Demsky. "Speculative Region-based Memory Management for Big Data Systems", the 8th Workshop on Programming Languages and Operating Systems (PLOS), Monterey, CA, October 4, 2015. (Acceptance rate: 7/16, 44%) [PDF] [Slides]
  • Lu Fang, Khanh Nguyen, Guoqing Xu, Brian Demsky, and Shan Lu. "Interruptible Tasks: Treating Memory Pressure As Interrupts for Highly Scalable Data-Parallel Programs", the 25th ACM Symposium on Operating Systems Principles (SOSP), Monterey, CA, October 4-7, 2015. (Acceptance rate: 30/186, 16%) [PDF] [1-column PDF] [Slides]
  • Khanh Nguyen, Kai Wang, Yingyi Bu, Lu Fang, Jianfei Hu, and Guoqing Xu. "Facade: A Compiler and Runtime for (Almost) Object-Bounded Big Data Applications", the 20th International Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS), Istanbul, Turkey, March 14-18, 2015. (Acceptance rate: 48/287, 17%) [PDF] [Slides]
  • Khanh Nguyen, and Guoqing Xu. "Cachetor: Detecting Cacheable Data to Remove Bloat", Joint Meeting of the European Software Engineering Conference and the ACM SIGSOFT Symposium on the Foundations of Software Engineering (ESEC/FSE), Saint Petersburg, Russia, August 18-26, 2013. (Acceptance rate: 51/251, 20%) [PDF] [Slides]
Research Projects
  • BigSAT: SAT solving at scale
    • Abstract: The mainstream SAT solvers are all based on the DPLL (David-Putnam-Logemann-Loveland) algorithm that is memory efficient but difficult to parallelize. To build a truly scalable SAT solver, we shift our focus to a long overlooked algorithm, the DP (David-Putnam) procedure, that performs explicit resolutions over clauses. DP consumes more memory but exhibits data parallelism, lending itself to systems optimizations that achieve efficiency and scalability by utilizing large computing resources.
    • This work is under development. We will report the result soon.

  • Yak: a high-performance Big-Data-friendly garbage collector
    • Abstract: Big Data applications often are written in managed languages and have a clear logical distinction between a control path and a data path. These two paths follow different heap usage patterns. State-of-the-art garbage collectors while are effective in the control path, are fundamentally limited in the data path, where most objects are created. This project aims to provide an automated and systematic JVM-based solution while requiring minimal user effort. Our results shows that we can effectively reduce the GC time and improve end-to-end performance considerably.
    • The paper was accepted in OSDI'16. [PDF].
    • The poster presented in PLDI'16 SRC.
    • This work was presented at the SoCal PLS Workshop in Fall 2016 at UC Irvine.

  • Interruptible Tasks: Treating memory pressure as interrupts
    • Abstract: Real-world data-parallel tasks developed in managed languages such as Java and C# commonly suffer from great memory pressure. This leads to excessive GC effort and out-of-memory errors, significantly hurting system performance and scalability. Interruptible task is a new type of data-parallel task that can be interrupted upon memory pressure—with part or all of their used memory reclaimed—and resumed when the pressure goes away. Experiments on two state-of-the-art platforms Hadoop and Hyracks show the effectiveness of the technique. All 13 reproduced real-world out-of-memory problems reported on Hadoop are solved using our system. A second set of experiments with 5 already well-tuned programs in Hyracks on datasets of different sizes shows that the our versions are 1.5–3× faster and scale to 3–24×+ larger datasets.
    • The paper was accepted in SOSP'15. [PDF] [1-column PDF].
    • The poster presented in SOSP'15 and an earlier version in ASPLOS'15 SRC.

  • Facade: a compiler and runtime support for (almost) object-bounded Big Data applications
    • Abstract: Popular Big Data platforms use managed object-oriented programming language such as Java due to its quick development cycle and rich community resources. However, when object-orientation meets Big Data, the cost of the managed runtime system is significantly magnified and becomes a scalability-prohibiting bottleneck. This project aims to remove this bottleneck in Big Data applications by introducing the novel compiler framework called Facade. Facade can automatically generate highly efficient data manipulation code by transforming the data path of an existing Big Data application. The key to efficiency is that in the generated code, the number of heap objects created for data types in each thread is statically bounded regardless of how much data an application has to process. Using Facade, one can obtain significantly reduced memory management costs and improved scalability.
    • The paper was accepted in ASPLOS'15. [PDF].
    • Using this project, I competed and won the third prize (bronze medal) in the ACM Student Research Competition in PLDI'14. The poster presented in PLDI'14 is here.
    • This work was presented at the SoCal PLS Workshop in Spring 2014 at Harvey Mudd College.

  • Cachetor: Detecting cacheable data to remove bloat
    • Abstract: Modern object-oriented software commonly suffers from runtime bloat that significantly affects its performance and scalability. One pattern of bloat is the work repeatedly done to compute the same data values. Cachetor is a novel runtime profiling tool that is effective in exposing caching opportunities and substantial performance gains can be achieved by modifying the program to cache the reported data.
    • The paper was accepted in ESEC/FSE'13. [PDF]
    • This work was presented at the SoCal PLS Workshop in Fall 2012 at UC Riverside.

Asides from my research and programming, I am interested in individual taxation laws. I volunteered in the IRS-sponsored VITA program, which helps low-income individuals and families prepare their tax returns, in 2011-2014.

In 2015, I was the UCI liaison and project manager for the Orange County United Way's Free Tax Preparation Campaign. I managed the development of an online scheduling and volunteer management platform with several UCI undergraduates.

I am the research group's coordinator, working with prospective summer interns. I'm proud to say that in the school of ICS, our group is one of the few groups that have been accepting high school students and undergraduates for summer internship for a number of years. The experience has been very positive for the interns and the group.


Starting Fall 2017, I am supported by a Google PhD Fellowship. Thanks, Google!

I greatly appreciate the Donald Bren School of Information and Computer Sciences for awarding me the Dean's Fellowship with four years of support for my study. My gratitude also goes to organizations such as NSF, ACM, USENIX, ACM SIGSOFT, ACM SIGPLAN (PAC), and ACM SIGOPS for their travel grants.