Research

I primarily work in the fields of operating systems and networking; my current projects include:

Isolation and Consolidation at the Edge: The shift of computation away from centralized data centers into 5G-based edge clouds promises to reduce latency… but only if our software infrastructures can evolve to efficiently host a diverse range of applications in a safely isolated multi-tenant environment. We have several projects exploring problems in this space, ranging from clean slate OS designs (Usenix ATC 2020) to secure lightweight containers. Much of our work focuses on how Serverless computing can be redesigned to be more efficient (EuroSys 21) and better fit Edge environments (SoCC 21). This work is supported in part by NSF grants CNS-1763548, CNS-1815690, and CPS-1837382.

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 demonstrated the power of this platform with a self-managing, high speed load balancer for memcached clusters (ICAC 16 Best Paper), explored extreme scalability (Co-NEXT 16), service chain scheduling (SIGCOMM 17), and protocol-stack (SIGCOMM 18) related challenges. This work is supported in part by NSF CNS-1422362 and NSF CRI-1823236. 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 virtualization 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, NSF SaTC-1814234, the Comcast Technology Research and Development Fund, and a Google Faculty Award.

Selected Recent Publications

My full publication list is available on Google Scholar or on my CV. Here are some recent publications most representative of my ongoing work.

• Mu: An Efficient, Fair and Responsive Serverless Framework for Resource-Constrained Edge Clouds. Viyom Mittal, Shixiong Qi, Ratnadeep Bhattacharya, Xiaosu Lyu, Junfeng Li, Sameer G Kulkarni, Dan Li, Jinho Hwang, K. K. Ramakrishnan, Timothy Wood. ACM Symposium on Cloud Computing (SOCC 21), November 2021.
• OFC: an opportunistic caching system for FaaS platforms. Djob Mvondo, Mathieu Bacou, Kevin Nguetchouang, Lucien Ngale, Josiane Kouam, Renaud Lachaize, Jinho Hwang, Timothy Wood, Daniel Hagimont, Noel De Palma, Batchakui Bernabé, and Alain Tchana. EuroSys 2021, April 2021
• Fine-Grained Isolation for Scalable, Dynamic, Multi-Tenant Edge Clouds. Yuxin Ren, Guyue Liu, Vlad Nitu, Wenyuan Shao, Riley Kennedy, Gabriel Parmer, Timothy Wood, and Alain Tchana. Usenix Annual Technical Conference (Usenix ATC 20), July 2020.
• CRIMES: Using Evidence to Secure the Cloud. Sundaresan Rajasekaran, Harpreet Singh Chawla, Zhen Ni, Neel Shah, Emery Berger, Timothy Wood. ACM/IEEE/IFIP Middleware Conference, December 2018.
• REINFORCE: Achieving Efficient Failure Resiliency for Network Function Virtualization based Services. Sameer G. Kulkarni, Guyue Liu, K. K. Ramakrishnan, Mayutan Arumaithurai, Timothy Wood, and Xiaoming Fu. ACM CoNEXT, December 2018.
• Microboxes: High Performance NFV with Customizable, Asynchronous TCP Stacks and Dynamic Subscriptions. Guyue Liu, Yuxin Ren, Mykola Yurchenko, K.K. Ramakrishnan, and Timothy Wood. ACM SIGCOMM, August 2018.
• NFVnice: Dynamic Backpressure and Scheduling for NFV Service Chains. Sameer G Kulkarni, Wei Zhang, Jinho Hwang, Shriram Rajagopalan, K.K. Ramakrishnan, Timothy Wood, Mayutan Arumaithurai, and Xiaoming Fu. ACM SIGCOMM, August 2017.
• Flurries: Countless Fine-Grained NFs for Flexible Per-Flow Customization. Wei Zhang, Jinho Hwang, Shriram Rajagopalan, K. K. Ramakrishnan, Timothy Wood. ACM Co-NEXT, December 2016.
• Netalytics: Cloud-Scale Application Performance Monitoring with SDN and NFV. Guyue Liu, Michael Trotter, Yuxin Ren, Timothy Wood. ACM/IFIP/USENIX Middleware, December 2016.
• OpenNetVM: A Platform for High Performance Network Service Chains. Wei Zhang, Guyue Liu, Wenhui Zhang, Neel Shah, Phil Lopreiato, Gregoire Todeschi, K.K. Ramakrishnan, and Timothy Wood. ACM SIGCOMM Workshop on Hot Topics in Middleboxes and Network Function Virtualization, August 2016.
• NetKV: Scalable, Self-Managing, Load Balancing as a Network Function. Wei Zhang, Timothy Wood, Jinho Hwang. International Conference on Autonomic Computing (ICAC 16), July 2016. Best Paper Award
• IOrchestra: Supporting High-performance Data-intensive Applications in the Cloud via Collaborative Virtualization. Ron C. Chiang, H. Howie Huang, Timothy Wood, Changbin Liu, Oliver Spatscheck. Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis (SC), November 2015.
• NetVM: High Performance and Flexible Networking using Virtualization on Commodity Platforms. Jinho Hwang, K.K. Ramakrishnan, Timothy Wood. Usenix Symposium on Networked System Design and Implementation (NSDI), April 2014. Extended TNSM journal version.

Service

My recent Program Committee service includes:

• ACM/IFIP/USENIX Middleware Conference (Middleware ‘14, 15, ‘16, ‘20)
• IEEE International Conference on Autonomic Computing and Self-Organizing Systems (ACSOS 2020) - Inaugural TPC Co-Chair
• ACM Conference on emerging Networking EXperiments and Technologies (CoNEXT ‘18, ‘20)
• IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN ‘19, ‘20)
• ACM/IEEE Symposium on Architectures for Networking and Communication Systems (ANCS 2018, 2019)
• IEEE/IFIP International Conference on Dependable Systems and Networks (DSN 2020)
• ACM Special Interest Group on Data Communication (SIGCOMM 2019) - Travel Grants Chair
• IEEE International Conference on Autonomic Computing (ICAC ‘19)
• The Web Conference (WWW ‘19)
• ACM/IEEE Symposium on Architectures for Networking and Communications Systems (ANCS ‘18)
• IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN ‘18) - General Co-Chair
• USENIX Symposium on Networked Systems Design and Implementation (NSDI ‘18)
• ACM/IFIP/USENIX Middleware Conference (Middleware ‘17, ‘18) - Student Activities Chair
• USENIX Annual Technical Conference (USENIX ATC ‘17)
• International Teletraffic Congress (ITC ‘17)
• IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN ‘17) - TPC Co-Chair
• IEEE Privacy-Aware Computing Conference (PAC ‘17) - Local Arrangements Chair
• IEEE International Conference on Autonomic Computing (ICAC ‘17) - Proceedings Chair
• Cloud-Assisted Networking Workshop, co-located with ACM CoNEXT (CAN ‘16) - Co-Chair

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.