I am a Computer Science Ph.D. candidate at Johns Hopkins University. I am fortunate to be advised by Dr. Soudeh Ghorbani. My research interests span around designing operating systems and host networking componenets for datacenter applications. For my thesis, I'm investigating the sources and implications of data center traffic burstiness.

Education

• 2019-2025
  • Computer Science Ph.D., Johns Hopkins University
• 2019-2021
  • Computer Science M.S.Eng., Johns Hopkins University
• 2016-2018
  • Computer Software Engineering MSc., Iran University of Science and Technology
• 2012-2016
  • Computer Software Engineering BSc., Iran University of Science and Technology

Current Research

• Today's datacenter workloads are prone to creating bursts of packets that can create congestion and degrade application performance. We are investigating ways to identify, measure and mitigate bursty traffic.
• Host networking stack components can contribute to uncontrolled bursts. We identify how network stack internals shape the traffic on the wire.
• Fair packet scheduling is often represented by Deficit Round-Robin (DRR) scheduling. We argue that DRR's assumptions no longer hold under today's diverse Internet traffic and propose Self-Clocked Round-Robin Scheduling with excellent latency and fairness for interactive flows such as streaming.
• Power efficiency is an improtant consideration for large-scale data center infrastructure. We investigate how to use application knowledge for CPU scheduling and power management for latency-sensitive distributed in-memory data stores.

Publications

Self-Clocked Round-Robin Packet Scheduling

Erfan Sharafzadeh, Raymond Matson, Jean Tourrilhes, Puneet Sharma, Soudeh Ghorbani. 2025. Self-Clocked Round-Robin Packet Scheduling. To appear in NSDI '25

Practical Packet Deflection in Datacenters

Sepehr Abdous, Erfan Sharafzadeh, Soudeh Ghorbani. 2023. Practical Packet Deflection in Datacenters. In CoNEXT '23 (ACM Netw. vol 1)

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Understanding the impact of host networking elements on traffic bursts

Erfan Sharafzadeh,Sepehr Abdous, Soudeh Ghorbani. 2023. Understanding the impact of host networking elements on traffic bursts. In NSDI '23.

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Understanding Microquanta Process Scheduling for Cloud Applications

Erfan Sharafzadeh, Alireza Sanaee, Peng Huang, Gianni Antichi, Soudeh Ghorbani. 2022. Understanding Microquanta Process Scheduling for Cloud Applications. In ACM/IEEE CloudAM '22.

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Poster: A high-resolution study of data center traffic at its origin

Erfan Sharafzadeh, Soudeh Ghorbani. 2021. Poster: A high-resolution study of data center traffic at its origin. In CoNEXT '21

Burst-tolerant datacenter networks with Vertigo

Sepehr Abdous*, Erfan Sharafzadeh*, and Soudeh Ghorbani. 2021. Burst-tolerant datacenter networks with Vertigo. In CoNEXT '21, *co-first authors

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Peafowl: In-application CPU Scheduling to Reduce Power Consumption of In-memory Key-Value Stores

Esmail Asyabi, Azer Bestavros, Erfan Sharafzadeh, Timothy Zhu. 2020. Peafowl: In-application CPU Scheduling to Reduce Power Consumption of In-memory Key-Value Stores. In SoCC '20

Yawn: A CPU Idle-state Governor for Datacenter Applications

Erfan Sharafzadeh, Seyed Alireza Sanaee Kohroudi, Esmail Asyabi, and Mohsen Sharifi. 2019. Yawn: A CPU Idle-state Governor for Datacenter Applications. In APSys '19

CTS: An Operating System CPU Scheduler to Mitigate Tail Latency for Latency-Sensitive Multi-Threaded Applications

Esmail Asyabi, Erfan Sharafzadeh, SeyedAlireza SanaeeKohroudi, Mohsen Sharifi, CTS: An operating system CPU scheduler to mitigate tail latency for latency-sensitive multi-threaded applications, JPDC 2019

Professional and Work Experience

• Research Associate Intern, Hewlett Packard Labs, Hewlett Packard Enterprise, Summer 2023 - Present.
• Artifact evaluation committee member, 2023 ACM Symposium on Operating Systems Principles (SOSP 2023)
• Shadow PC member, 2022 ACM European Conference on Computer Systems (EuroSys 2022).
• Shadow PC member, 2021 ACM European Conference on Computer Systems (EuroSys 2021).
• Design and development of "Shariffood", Sharif University of Technology dorms meal reservation portal.
• Infrastructure lead of IUST Cloud Computing Center: Iran University of Science and Technology IAAS Cloud platform.

Teaching Assistance

• Fall 2016, Advanced Programming, IUST.
• Fall 2017, Operating Systems, IUST
• Spring 2018, Cloud Computing Environments, IUST
• Fall 2018, Operating Systems, IUST
• Spring 2020, Cloud Computing, JHU, course page
• Fall 2022, Computer Networks, JHU, course page

News

• April 17, 2025

  I will be attending NSDI '25 in Philadephia to present our paper, SCRR. Looking forward to meeting you there!

• April 16, 2025

  I defended my Ph.D. dissertation titled "Identifying and Addressing the Implications of Bursty Network Traffic" under the guidance of my advisor, Dr. Soudeh Ghorbani.

• Dec 11, 2024

  Our paper "Self-Clocked Round-Robin Packet Scheduling" is accepted to appear in NSDI '25. SCRR redefines fair packet scheduling for low latency Internet applications!

• Nov 14, 2023

  Our paper "Practical packet deflection for datacenters" is accepted at CoNEXT '23. Can't wait to present our findings in Paris!

• Apr 28, 2023

  I'll be joining the NDSL group at Hewlett Packard Labs as a Research Intern this summer!

• Apr 16, 2023

  I'll be presenting our paper, Valinor, at the NSDI '23 conference in the congestion control track. Grateful to Usenix for the travel award!

• Dec 15, 2022

  Our paper Valinor got accepted to NSDI '23. I'm thrilled to present how network traffic bursts manifist themselves at different scales!

• Dec 5, 2022

  I had the privilege to present our work on Microquanta process scheduler at IEEE/ACM CloudAM 2022 workshop, part of the UCC '22 conference. Grateful for NSF's travel award!

• Dec 7, 2021

  I presented our paper "Vertigo" in the virtual CoNEXT '21 conference. Vertigo proposes selective deflection routing to overcome the impact of microbursts on packet loss and flow performance.

Misc

When I'm away from my PC, I play soccer (goalkeeper indoors, full back outdoors!), play video games (Fable and Far cry fan!), or leaf through my favorite books (I'm a Tolkien fan). Let's chat if our interests align ;)

Contact

You can contact me through my academic email or my personal email.