Mahadev Satyanarayanan

Mahadev "Satya" Satyanarayanan is an Indian experimental computer scientist, an ACM and IEEE fellow, and the Carnegie Group Professor of Computer Science at Carnegie Mellon University (CMU).

He is credited with many advances in edge computing, distributed systems, mobile computing, pervasive computing, and Internet of Things.

His research focus is around performance, scalability, availability, and trust challenges in computing systems from the cloud to the mobile edge.

He has a bachelor's and master's degree from Indian Institute of Technology, Madras in 1975 and 1977, and his Ph.D. in computer science from CMU in 1983.

Satya was a principal architect and implementer of the Andrew File System (AFS), the technical forerunner of modern cloud-based storage systems.

From its conception in 1983 as the unifying campus-wide IT infrastructure for CMU, AFS evolved through versions AFS-1, AFS-2 and AFS-3.

The AFS papers in 1985 and 1987 also received Outstanding Paper awards at the ACM Symposium on Operating System Principles.

AFS has been continuously deployed at CMU since 1986, at a scale of many thousands of users.

In 1987, Satya began work on the Coda File System to address a fundamental shortcoming of AFS-like systems.

Extensive first-hand experience with the AFS deployment at CMU showed that users are severely impacted by server and network failures.

This vulnerability is not just hypothetical, but indeed a fact of life in real-world deployments.

Once users become critically dependent on files cached from servers, a server or network failure renders these files inaccessible and leaves clients crippled for the duration of the failure.

In a large enough system, unplanned outages of servers and network segments are practically impossible to avoid.

Today's enthusiastic embrace of cloud computing rekindles many of these concerns because of increased dependence on centralized resources, The goal of the Coda project was to preserve the many strengths of AFS, while reducing its vulnerability to failures.

Coda was the first system to show how server replication could be combined with client caching to achieve good performance and high availability.

Coda invented the concept of "disconnected operation", in which cached state on clients is used to mask network and server failures.

Coda also demonstrated bandwidth-adaptive weakly-connected operation over networks with low bandwidth, high latency or frequent failures.

Coda's use of optimistic replication, trading consistency for availability, was controversial when introduced.

Today, it is a standard practice in all data storage systems for mobile environments.

Coda also pioneered the concept of translucent caching, which balances the full transparency of classic caching with the user visibility needed to achieve a good user experience on bandwidth-challenged networks.

The Coda concepts of hoarding, reintegration and application-specific conflict resolution are found in the cloud sync capabilities of virtually all mobile devices today.

In mid-1989, AFS-3 was commercialized by Transarc Corporation and its evolution continued outside CMU.

Transarc was acquired by IBM, and AFS became an IBM product for a number of years.

Papers relating to Coda received Outstanding Paper awards at the 1991 and 1993 ACM Symposium on Operating System Principles.

In 2000, IBM released the code to the open source community as OpenAFS.

Since its release as OpenAFS, the system has continued to be used in many enterprises all over the world.

In the academic and research lab community, OpenAFS is in use at more than 30 sites in the United States (including CMU, MIT, and Stanford) and dozens of sites in Europe, New Zealand, and South Korea.

Many global companies have used OpenAFS including Morgan Stanley, Goldman Sachs, Qualcomm, IBM, United Airlines, Pfizer, Hitachi, InfoPrint, and Pictage.

Over a 30-year period, AFS has been a seminal influence on academic research and commercial practice in distributed data storage systems for unstructured data.

The design principles that were initially discovered and validated in the creation and evolution of AFS have influenced virtually all modern commercial distributed file systems, including Microsoft DFS, Google File System, Lustre File System, Ceph, and NetApp ONTAP.

In addition, AFS inspired the creation of DropBox whose founders used AFS as part of Project Athena at MIT.

It also inspired the creation of Maginatics, a startup company advised by Satya that provides cloud-sourced network-attached storage for distributed environments.

The NFS v4 network file system protocol standard has been extensively informed by the lessons of AFS.

Key ideas from Coda were incorporated by Microsoft into the IntelliMirror component of Windows 2000 and the Cached Exchange Mode of Outlook 2003.

In addition, he was the founding director of Intel Research Pittsburgh and an advisor to the company Maginatics, which was acquired by EMC in 2014.

His work on disconnected operation in Coda File System received the ACM SIGOPS Hall of Fame Award in 2015 and the inaugural ACM SIGMOBILE Test-of-Time Award in 2016.

He served as the founding Program Chairman of the IEEE/ACM Symposium on Edge Computing and the HotMobile workshops, the founding Editor-in-Chief of IEEE Pervasive Computing, and the founding Area Editor for the Synthesis Series on Mobile and Pervasive Computing.

His work on the Andrew File System (AFS) was recognized with the ACM Software System Award in 2016 and the ACM SIGOPS Hall of Fame Award in 2008 for its influence and impact.

In 2016, AFS was honored with the prestigious ACM Software System Award.

Earlier, ACM recognized the significance of AFS by inducting a key paper on it to the ACM SIGOPS Hall of Fame.