I am a computer science Assistant Professor at The George Washington University and one of the directors of the Cloud Systems Lab. I teach and do research in the general areas of operating systems and distributed systems. I am particularly interested in how new virtualization technologies can provide application agnostic tools that improve performance, efficiency, and reliability in cloud computing data centers and software-based networks. My research focuses on practical, systems-level challenges created by emerging technologies in these areas.
Prior to joining GW I was a Ph.D. student at the University of Massachusetts Amherst working with Prashant Shenoy. Before that I was an ECE undergraduate at Rutgers University and did research with Yanyong Zhang in the WINLAB.
I primarily work in the fields of operating systems and networking; my current projects include:
Software Defined Network Function Virtualization: We are designing the software infrastructures and management algorithms needed to transition network services like routers, firewalls, and intrusion detection systems from running on hardware to more flexible, software-based environments. The basis for our research is OpenNetVM (NSDI 14, HotMiddlebox 16), a high performance NFV platform that we have released as open source to the research community. Through careful optimizations at the systems-level, OpenNetVM can achieve packet processing rates of nearly 70Gbps, while retaining a flexible, SDN-controlled design. We have recently demonstrated the power of this platform with a self-managing, high speed load balancer for memcached clusters (ICAC 16 Best Paper). This work is supported in part by NSF CNS-1422362. More info here!
Efficient, Flexible, and Dependable Clouds: Modern data centers rely on virtualization to partition servers into isolated components. My early work on "black-box" and "gray-box" virtual machine management (NSDI 07) sought to evaluate the benefits and drawbacks of sending information across the virutalization abstraction layer for resource management. Since then we've explored how carefully puncturing the virtualization abstraction layer can be used to dynamically manage memory (VEE 09 Best Paper, Usenix ATC 12, VEE 14), storage (SC 15, IC2E 16) and CPU (IWQoS 12 Best Paper, CCGrid 14). We've also investigated the challenges with defending cloud services from both natural disasters (SoCC 11) and malicious attacks (EuroSys 11, HotCloud 16). This work is supported in part by NSF CNS-1525992, an NSF CAREER Award, the Comcast Technology Research and Development Fund, and a Google Faculty Award.
The full list of courses I have taught is available here.
I'm proud to have been selected as the GW ACM Professor of the Year Award in 2015, recipient of the GW SEAS Outstanding Teacher Award for an Assistant Professor in 2014, and the GW Engineer’s Council CS Professor of the Year in 2013.
A condensed timeline of events:
- 4/16/2017: I've received the GW SEAS Outstanding Junior Researcher Award!
- 9/12/2016: Our paper on efficiently running LOTS of NFs (80,000+ per second) has been accepted at Co-NEXT! This was a collaboration with IBM and UCR. I'm also co-chairing the Cloud Assisted Networking Workshop at Co-NEXT.
- 5/25/2016: This summer my students Grace Liu will intern at Hewlett Packard Labs and Wei Zhang will intern at AT&T Labs Research.
- 9/1/2015: I have received a grant from NSF's Secure and Trustworthy Cyberspace division. The project, titled EVADE: Evidence Assisted Detection and Evasion of Security Vulnerabilities is a joint effort with Emery Berger from the University of Massachusetts Amherst and will explore operating system and virtualization layer techniques to efficiently detect attacks before they are able to adversely affect a system.
- 12/3/2014: Congrats to my Ph.D. student Grace Liu for winning the HP Women of Openstack Scholarship!
- 9/12/2014: My NSF grant Software Defined Network Function Virtualization (SDNFV) - Flexible, High Performance Network and Data Center Virtualization has been approved. This work will be a collaboration with K.K. Ramakrishnan from UC Riverside.
- 1/5/2014: Our paper NetVM: High Performance and Flexible Networking Using Virtualization on Commodity Platforms has been accepted at NSDI 2014!
- 11/12/2013: My first Ph.D. student, Jinho Hwang has defended his thesis! Jinho will be starting a Post Doc at IBM Research TJ Watson next month.
- 1/14/2013: My NSF Career Award: Application-Agnostic, Distributed-Aware Cloud Platforms has been funded!
- 6/5/2012: Jinho presented our paper at IWQoS and won a Best Student Paper award!
- 10/24/2011: My PhD dissertation has been selected for an Outstanding Dissertation Award by the UMass Computer Science department (sponsored by Yahoo). It was also nominated for the ACM's Doctoral Dissertation Award.
- 8/1/2011: I began as an assistant professor at George Washington University after finishing my Ph.D. at University of Massachusetts Amherst.
Google Scholar reports that my 50+ papers have been cited over 4000 times, with an h-index of 21. Here are some of the highlights of my work.
Flurries: Countless Fine-Grained NFs for Flexible Per-Flow Customization. Wei Zhang, Jinho Hwang, Shriram Rajagopalan, K. K. Ramakrishnan, Timothy Wood. Co-NEXT 16. PDF
OpenNetVM: A Platform for High Performance Network Service Chains. Wei Zhang, Guyue Liu, Wenhui Zhang, Neel Shah, Phillip Lopreiato, Gregoire Todeschi, K.K. Ramakrishnan, Timothy Wood. HotMiddlebox 16. PDF (Source code: https://github.com/sdnfv/openNetVM)
NetKV: Scalable, Self-Managing, Load Balancing as a Network Function. Wei Zhang, Timothy Wood, Jinho Hwang. ICAC 16. PDF (Karsten Schwan Best Paper Award)
NetVM: High Performance and Flexible Networking using Virtualization on Commodity Platforms. Jinho Hwang, K.K. Ramakrishnan, Timothy Wood. NSDI 14. PDF (18% acceptance)
Mortar: Filling the Gaps in Data Center Memory. Jinho Hwang, Ahsen Uppal, Timothy Wood, H. Howie Huang. VEE 14. PDF (36% acceptance)
HybridMR: A Hierarchical MapReduce Scheduler for Hybrid Data Centers. Bikash Sharma, Timothy Wood, Chita R. Das. ICDCS 13. PDF (13% acceptance rate)
An Empirical Study of Memory Sharing in Virtual Machines. Sean Barker, Timothy Wood, Prashant Shenoy, Ramesh Sitaraman. USENIX ATC 12. PDF (14% acceptance rate)
Adaptive Dynamic Priority Scheduling for Virtual Desktop Infrastructures. Jinho Hwang, Timothy Wood. IWQoS 12. PDF (Best Student Paper Award, 22% acceptance rate)
PipeCloud: Using Causality to Overcome Speed-of-Light Delays in Cloud-Based Disaster Recovery. Timothy Wood, Andres Lagar-Cavilla, K. K. Ramakrishnan, Prashant Shenoy, Jacobus Van der Merwe. SoCC 11. PDF (17% acceptance rate)
ZZ and the Art of Practical BFT Execution. Timothy Wood, Rahul Singh, Arun Venkataramani, Prashant Shenoy, Emmanuel Cecchet. EuroSys 11. PDF (15% acceptance rate)
CloudNet : Dynamic Pooling of Cloud Resources by Live WAN Migration of Virtual Machines. Timothy Wood, K. K. Ramakrishnan, Prashant Shenoy, Jacobus Van der Merwe. VEE 11. PDF (29% acceptance rate. Journal version in IEEE/ACM Transactions on Networking, 2015)
Memory buddies: Exploiting Page Sharing for Smart Colocation in Virtualized Data Centers. Timothy Wood, Gabriel Tarasuk-Levin, Prashant Shenoy, Peter Desnoyers, Emmanuel Cecchet, Mark D. Corner. VEE 09. PDF (35% acceptance rate)
Black-Box and Gray-Box Strategies for Virtual Machine Migration. Timothy Wood, Prashant Shenoy, Arun Venkataramani, Mazin Yousif. NSDI 07. PDF (24% acceptance rate, Journal + Conference versions have 1000+ citations)
I am fortunate to work with a variety of excellent PhD students:
- Jinho Hwang - now at IBM Research
- Zhen Ni
- Michael Trotter
If I am listed as your MS advisor, I can help you plan your degree. However, before sending me email you should check this MS Advising FAQ. It will answer the vast majority of your questions.
I have been or will be a member of the program committee for the following conferences:
- ACM/IFIP/USENIX Middleware Conference (Middleware 2017) - Student Activities Chair
- IEEE Privacy-Aware Computing Conference (PAC 2017) - Local Arrangements Chair
- IEEE International Conference on Autonomic Computing (ICAC 2017) - Proceedings Chair
- ACM/SPEC International Conference on Performance Engineering (ICPE 2016) - Publicity Co-Chair
I have acted as an external reviewer for a number of conferences and journals including:
- NSDI, HotCloud, SenSys, Usenix ATC, EuroSys, IEEE TPDS, IEEE TCC, IEEE TC, IEEE TAAS, IEEE TNSM, IEEE TR, IEEE/ACM ToN, ACM Computing Surveys, Elsevier JPDC, VLDB Journal, and Sigops Operating Systems Review
I also run an outreach program to local high schools that teaches students how the popular websites they use are actually built. Contact me if you are interested in this program.
Perhaps these will be useful for others as well…
If you are currently a student at GW or are applying to the Ph.D. program, contact me if you are interested in working on distributed systems or cloud computing problems. You can read more about what I expect from potential graduate students here.