Ram Alagappan

Assistant Professor, Computer Science, UIUC
Email: ramn@illinois.edu
Office: 3122 Siebel Center, 201 N Goodwin Ave, Urbana, IL 61801

DASSL Research Group
CV | Google Scholar | DBLP

I am an Assistant Professor in the Department of Computer Science at the University of Illinois Urbana-Champaign. I am a computer systems researcher. My work spans storage, memory, and distributed systems. I am often interested in improving the reliability and performance of these systems.

I co-lead the Distributed And Storage Systems Laboratory (DASSL) at UIUC CS.

I am always looking for self-motivated, hardworking, and creative PhD students. If you are interested in systems (OS, memory, storage, distributed systems), please apply to the UIUC CS PhD program and mention my name in the application.

Latest
[Jun 25] Invited talk at TigerBeetle's Systems Distributed 25.
[Dec 24] Awarded NetApp faculty fellowship!
[Nov 24] LazyLog won the Best Paper Award at SOSP 24!
[Nov 24] Co-chaired the Systems Doctoral Workshop at SOSP 2024.
[Oct 24] Invited talk at University of Pennsylvania Distributed Systems Laboratory.
[Sep 24] Invited talk at UC Berkeley Sky Computing Lab.
[Aug 24] Our work on low-latency shared logs will appear in SOSP 24.
[May 24] Will serve on NSDI 25 PC.
[May 24] Will serve on SOCC 25 PC.
[Jan 24] NSF CAREER Award.
[Jan 24] UIUC List of Teachers Ranked as Outstanding (for CS598 - Storage Systems Fall 2023).
[Dec 23] Our work on high-performance replication for KV stores will appear in FAST 24.
[Oct 23] Invited to co-chair ICDCS track on Algorithms for Distributed Computing, Scheduling and OS.
[Sep 23] Invited to serve on the PC for SOSP 24, EuroSys 24 Fall, Systor 24, HotStorage 24.
[Sep 23] Our work on disaggregated storage fault tolerance will appear in EuroSys 24.
[Jun 23] UIUC List of Teachers Ranked as Excellent (for CS598 - Storage Systems Spring 2023).
[Jan 23] UIUC List of Teachers Ranked as Excellent (for CS598 - Storage Systems Fall 2022).

Awards

Research

Best Paper SOSP '24 - LazyLog
NSF CAREER Award
Best Paper FAST '20 - CAD
UW CS Graduate Student Research (Best Dissertation Research) Award - Honorable Mention - 2019
Best Paper FAST '18 - PAR/CTRL
Best Paper FAST '17 - CCFS
Best Paper Nominee FAST '17- Redundancy Does Not Imply Fault Tolerance

Teaching

List of Teachers Ranked as Outstanding at UIUC (for CS598 - Storage Systems Fall 2023)
List of Teachers Ranked as Excellent at UIUC (for CS598 - Storage Systems Spring 2023)
List of Teachers Ranked as Excellent at UIUC (for CS598 - Storage Systems Fall 2022)
CS 739 ranked 1st among all Spring 20 courses in student evaluations
Nominated for SACM CoW Teaching Award for CS 739

Service

Distinguished Reviewer HotStorage - 2021
Best Shadow PC Reviewer Eurosys '19

Grants and Scholarships

IBM-IL Discovery Accelerator Institute (IIDAI) grant 2024
MS Azure Credits Research Award for $50,000 - 2019
Facebook Distributed Systems Research Award for $50,000 - 2019
Alumni Scholarship, UW Madison - 2013

Publications

[Conference] [Workshop] [Journal & Invited]

Conference Publications


Low End-to-End Latency atop a Speculative Shared Log with Fix-Ante Ordering
Shreesha G. Bhat, Tony Hong, Xuhao Luo, Jiyu Hu, Aishwarya Ganesan, Ramnatthan Alagappan
OSDI 2025
PDF
OSDI '25
LazyLog: A New Shared Log Abstraction for Low-Latency Applications
Xuhao Luo, Shreesha G. Bhat*, Jiyu Hu*, Ramnatthan Alagappan, Aishwarya Ganesan
*=equal contribution. SOSP 2024
PDF
Best Paper Award
SOSP '24
IONIA: High-Performance Replication for KV Stores
Yi Xu*, Henry Zhu*, Prashant Pandey, Alex Conway, Rob Johnson, Aishwarya Ganesan, Ramnatthan Alagappan
*=co-primary authors. FAST 2024
PDF
FAST '24
SplitFT: Fault Tolerance for Disaggregated Datacenters via Remote Memory Logging
Xuhao Luo, Ramnatthan Alagappan, Aishwarya Ganesan
EuroSys 2024
PDF
EuroSys '24
Automatic Reliability Testing For Cluster Management Controllers
Xudong Sun, Wenqing Luo, Tyler Gu, Aishwarya Ganesan, Ramnatthan Alagappan, Michael Gasch, Lalith Suresh, and Tianyin Xu
16th USENIX Symposium on Operating Systems Design and Implementation
PDF
OSDI '22
Exploiting Nil-Externality for Fast Replicated Storage
Aishwarya Ganesan, Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
28th ACM Symposium on Operating Systems Principles
PDF, Talk Slides, Video - short, Video - long, Code
Invited to Transactions on Storage
SOSP '21
The Storage Hierarchy is Not a Hierarchy: Optimizing Caching on Modern Storage Devices with Orthus
Kan Wu, Zhihan Guo, Guanzhou Hu, Kaiwei Tu, Ramnatthan Alagappan, Rathijit Sen, Kwanghyun Park, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
19th USENIX Conference on File and Storage Technologies
PDF
FAST '21
From Wisckey to Bourbon: A Learned Index for Log-structured Merge Trees
Yifan Dai, Yien Xu, Aishwarya Ganesan, Ramnatthan Alagappan, Brian Kroth, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Proceedings of the 14th Symposium on Operating System and Design Implementation
PDF
OSDI '20
Can Applications Recover from fsync Failures?
Anthony Rebello, Yuvraj Patel, Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
The 2020 USENIX Annual Technical Conference
PDF
Invited to Transactions on Storage
ATC '20
Strong and Efficient Consistency with Consistency-aware Durability
Aishwarya Ganesan, Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
18th USENIX Conference on File and Storage Technologies
PDF, Talk Slides
Best Paper Award
Invited to Transactions on Storage
FAST '20
Fault-Tolerance, Fast and Slow: Exploiting Failure Asynchrony in Distributed Systems
Ramnatthan Alagappan, Aishwarya Ganesan, Jing Liu, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Proceedings of the 13th Symposium on Operating System and Design Implementation
PDF, Talk Slides
OSDI '18
Protocol-Aware Recovery for Consensus-Based Storage
Ramnatthan Alagappan, Aishwarya Ganesan, Eric Lee, Aws Albarghouthi, Vijay Chidambaram, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Proceedings of the 16th USENIX Conference on File and Storage Technologies
PDF, Talk Slides
Best Paper Award
Invited to Transactions on Storage
Invited to ATC 19 Best of the Rest
Coverage: Morning Paper, zdnet
FAST '18
Atomic In-Place Updates for Non-Volatile Main Memories with KaminoTx
Amir Saman Memaripour, Anirudh Badam, Amar Phanishayee, Yanqi Zhou, Ramnatthan Alagappan, Karin Strauss, Steven Swanson
Proceedings of the Twelfth European Conference on Computer Systems
PDF
EuroSys '17
Redundancy Does Not Imply Fault Tolerance: Analysis of Distributed Storage Reactions to Single Errors and Corruptions
Aishwarya Ganesan, Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Proceedings of the 15th USENIX Conference on File and Storage Technologies
PDF, Talk Slides, Code
Best Paper Award Nominee
Invited to Transactions on Storage
Invited to Usenix ;login:
Coverage: StorageMojo, Morning Paper, DHSR's blog
FAST '17
Application Crash Consistency and Performance with C2FS
Thanumalayan Sankaranarayana Pillai, Ramnatthan Alagappan, Lanyue Lu, Vijay Chidambaram, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Proceedings of the 15th USENIX Conference on File and Storage Technologies
PDF, Talk Slides
Best Paper Award
Invited to Transactions on Storage
Invited to ATC 17 Best of the Rest
Coverage: Morning Paper
FAST '17
Correlated Crash Vulnerabilities
Ramnatthan Alagappan, Aishwarya Ganesan, Yuvraj Patel, Thanumalayan Sankaranarayana Pillai, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Proceedings of the 12th Symposium on Operating System and Design Implementation
PDF, Talk Slides, Code
OSDI '16
All File Systems Are Not Created Equal: On the Complexity of Crafting Crash-Consistent Applications
Thanumalayan Sankaranarayana Pillai, Vijay Chidambaram, Ramnatthan Alagappan, Samer Al Kiswany, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Proceedings of the 11th Symposium on Operating System and Design Implementation
PDF, Code
Invited to Communications of the ACM
Invited to ACM Queue
Coverage: Morning Paper
OSDI '14

Workshop Publications


Reasoning about modern datacenter infrastructures using partial histories
Xudong Sun, Lalith Suresh, Aishwarya Ganesan, Ramnatthan Alagappan, Michael Gasch, Lilia Tang, Tianyin Xu
HotOS 2021
HotOS '21
The Storage Hierarchy is Not a Hierarchy: Optimizing Caching on Modern Storage Devices with Orthus
Kan Wu, Zhihan Guo, Guanzhou Hu, Kaiwei Tu, Ramnatthan Alagappan, Rathijit Sen, Kwanghyun Park, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
NVMW 2021
NVMW '21
Too Many Knobs to Tune? Towards Faster Database Tuning by Pre-selecting Important Knobs
Konstantinos Kannelis, Ramnatthan Alagappan, Shivaram Venkataraman
15th Workshop on Hot Topics in Storage and File Systems
PDF
HotStorage '20
Beyond Storage APIs: Provable Semantics for Storage Stacks
Ramnatthan Alagappan, Vijay Chidambaram, Thanumalayan Sankaranarayana Pillai, Aws Albarghouthi, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
15th Workshop on Hot Topics in Operating Systems
PDF,
HotOS '15

Journal/Invited Publications


Exploiting Nil-Externalizing Interfaces for Fast Replicated Storage
Aishwarya Ganesan, Ramnatthan Alagappan, Anthony Rebello, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Transactions on Storage - May 2022
Fast tracked
PDF
TOS '22
Can Applications Recover from fsync Failures?
Anthony Rebello, Yuvraj Patel, Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Transactions on Storage - Vol. 17, Issue 2, June 2021
PDF
TOS '21
Strong and Efficient Consistency with Consistency-aware Durability
Aishwarya Ganesan, Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Transactions on Storage - Vol. 17, Issue 1, January 2021
Fast tracked
PDF
TOS '21
Protocol-Aware Recovery for Consensus-based Storage
Ramnatthan Alagappan, Aishwarya Ganesan, Eric Lee, Aws Albarghouthi, Vijay Chidambaram, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Usenix ATC 2019
Best of the Rest
Usenix ATC '19
Protocol-Aware Recovery for Consensus-Based Distributed Storage
Ramnatthan Alagappan, Aishwarya Ganesan, Eric Lee, Aws Albarghouthi, Vijay Chidambaram, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Transactions on Storage - Vol. 14, Issue 3, October 2018
Fast tracked
PDF
TOS '18
Redundancy Does Not Imply Fault Tolerance
Aishwarya Ganesan, Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Transactions on Storage - Vol. 13, Issue 3, September 2017
Fast tracked
PDF
TOS '17
Application Crash Consistency and Performance with CCFS
Thanumalayan Sankaranarayana Pillai, Ramnatthan Alagappan, Lanyue Lu, Vijay Chidambaram, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Usenix ATC 2017
Best of the Rest
PDF
Usenix ATC '17
Application Crash Consistency and Performance with CCFS
Thanumalayan Sankaranarayana Pillai, Ramnatthan Alagappan, Lanyue Lu, Vijay Chidambaram, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Transactions on Storage - Vol. 13, Issue 3, September 2017
Fast tracked
PDF
TOS '17
Redundancy Does Not Imply Fault Tolerance
Aishwarya Ganesan, Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
USENIX ;login: Volume 42, Number 2, 2017
PDF
USENIX ;login: Summer '17
Hybrid NVM Enabled Datacenter Design and Optimization
Yanqi Zhou, Ramnatthan Alagappan, Amir Samam Memaripour, Anirudh Badam, David Wentzlaff
MSR-TR-2017-8 Feb 2017
PDF
MSR TR
Crash Consistency: Rethinking the Fundamental Abstractions of the File System
Thanumalayan Sankaranarayana Pillai, Vijay Chidambaram, Ramnatthan Alagappan, Samer Al Kiswany, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
ACM Queue July 2015
PDF
ACM Queue
Crash Consistency:
Thanumalayan Sankaranarayana Pillai, Vijay Chidambaram, Ramnatthan Alagappan, Samer Al Kiswany, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Communications of the ACM - Vol. 58, No. 10, October 2015
PDF
CACM

WIPS/Posters


Atomic In-Place Updates for Non-Volatile Main Memories with KaminoTx
Amir Saman Memaripour, Anirudh Badam, Amar Phanishayee, Yanqi Zhou, Ramnatthan Alagappan, Karin Strauss, Steven Swanson

NVMW '18
Simple Crash Consistency With Streams
Thanumalayan Sankaranarayana Pillai, Ramnatthan Alagappan, Andrea Arpaci-Dusseau, Remzi Arpaci-Dusseau

FAST '16

Teaching

Fall 2022: CS 598 Storage Systems: Theory and Practice
Fall 2022: CS 591 SN Systems Seminar



Students

Currently, I work with a set of brilliant students in DASSL at Illinois.

Service


Program Committee OSDI '23
Poster Co-chair FAST '23
Program Committee SOCC '22
Program Committee HotStorage '22
Ask-Me-Anything Co-chair SOSP '21
OSDI Mentoring OSDI '21
EuroDW Mentoring EuroDW '21
Journal of Systems SEB Co-cair '21
EuroDW Program Committee EuroDW '21
Program Committee HotStorage '21 (Distinguished Reviewer)
Program Committee Systor '21
Reviewer ACM Transactions on Computer Systems '20
Program Committee HotStorage '20
Artifact Evaluation Committee Reviewer SOSP '19
Shadow Program Committee Reviewer Eurosys '19 (Best Reviewer Award)
Reviewer ACM Transactions on Storage '18
External Reviewer FAST '18
Contributor to PC reviews Eurosys '17
External Reviewer OSDI '16
External Reviewer FAST '16

Presentations and Invited Talks


Co-designing Distributed Systems and Storage Stacks for Improved Reliability
  • University of Waterloo Jan '22
  • Virginia Tech Jan '22
  • Pennsylvania State University Feb '22
  • University of Virginia Feb '22
  • Purdue University Feb '22
  • University of Utah Feb '22
  • University of Toronto Mar '22
  • University of Illinois at Urbana-Champaign Mar '22
  • University of Washington Mar '22
  • University of Michigan Mar '22
  • Massachusetts Institute of Technology Mar '22
  • University of North Carolina at Chapel Hill Mar '22
  • University of Southern California Mar '22
  • University of California, Santa Cruz Mar '22
  • University of California, Irvine Apr '22
Co-designing Distributed Systems and Storage Stacks @ Waterloo Oct 21 (invited)
Reliable Distributed Storage: A Local Storage Perspective @ Rutgers Aug 20 (invited)
Reliable Distributed Storage: A Local Storage Perspective @ VRG Jun 20 (postdoc interview talk)
Protocol-Aware Recovery for Consensus-Based Storage @ ATC '19 (invited conference talk)
Storage Systems at the Edge @ NSF-VMWare ECDI Summit (invited)
Fault-Tolerance, Fast and Slow: Exploiting Failure Asynchrony in Distributed Systems @ OSDI '18 (slides)
Protocol-Aware Recovery for Consensus-based Storage @ SNIA SDC '18 (invited, slides, video)
Resiliency to Storage Faults in Distributed Systems @ Google Madison May '18 (invited)
Protocol-Aware Recovery for Consensus-Based Storage @ FAST '18 (slides)
Rethinking Consensus with Local Storage in Mind @ SCI-labs 2017
Correlated Crash Vulnerabilities @ OSDI '16 (slides)
Correlated Crash Vulnerabilities @ Microsoft Gray Systems Lab

Software

DASSL projects

Old:
PACE: To check for correlated crash vulnerabilities in distributed systems
Code on GitHub
CORDS: To test corruption tolerance in distributed systems
Code on GitHub
ALICE: To check for crash vulnerabilities in local storage systems
Code on GitHub