Search Results

Documents authored by Sergey, Ilya


Document
Unifying Formal Methods for Trustworthy Distributed Systems (Dagstuhl Seminar 23112)

Authors: Swen Jacobs, Kenneth McMillan, Roopsha Samanta, and Ilya Sergey

Published in: Dagstuhl Reports, Volume 13, Issue 3 (2023)


Abstract
This report documents the program and the outcomes of Dagstuhl Seminar 23112 "Unifying Formal Methods for Trustworthy Distributed Systems". Distributed systems are challenging to develop and reason about. Unsurprisingly, there have been many efforts in formally specifying, modeling, and verifying distributed systems. A bird’s eye view of this vast body of work reveals two primary sensibilities. The first is that of semi-automated or interactive deductive verification targeting structured programs and implementations, and focusing on simplifying the user’s task of providing inductive invariants. The second is that of fully-automated model checking, targeting more abstract models of distributed systems, and focusing on extending the boundaries of decidability for the parameterized model checking problem. Regrettably, solution frameworks and results in deductive verification and parameterized model checking have largely evolved in isolation while targeting the same overall goal. This seminar aimed at enabling conversations and solutions cutting across the deductive verification and model checking communities, leveraging the complementary strengths of these approaches. In particular, we explored layered and compositional approaches for modeling and verification of industrial-scale distributed systems that lend themselves well to separation of verification tasks, and thereby the use of diverse proof methodologies.

Cite as

Swen Jacobs, Kenneth McMillan, Roopsha Samanta, and Ilya Sergey. Unifying Formal Methods for Trustworthy Distributed Systems (Dagstuhl Seminar 23112). In Dagstuhl Reports, Volume 13, Issue 3, pp. 32-48, Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2023)


Copy BibTex To Clipboard

@Article{jacobs_et_al:DagRep.13.3.32,
  author =	{Jacobs, Swen and McMillan, Kenneth and Samanta, Roopsha and Sergey, Ilya},
  title =	{{Unifying Formal Methods for Trustworthy Distributed Systems (Dagstuhl Seminar 23112)}},
  pages =	{32--48},
  journal =	{Dagstuhl Reports},
  ISSN =	{2192-5283},
  year =	{2023},
  volume =	{13},
  number =	{3},
  editor =	{Jacobs, Swen and McMillan, Kenneth and Samanta, Roopsha and Sergey, Ilya},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagRep.13.3.32},
  URN =		{urn:nbn:de:0030-drops-192278},
  doi =		{10.4230/DagRep.13.3.32},
  annote =	{Keywords: Deductive Verification, Distributed Algorithms, Formal Verification, Model Checking}
}
Document
Concurrent Data Structures Linked in Time (Artifact)

Authors: Germán Andrés Delbianco, Ilya Sergey, Aleksandar Nanevski, and Anindya Banerjee

Published in: DARTS, Volume 3, Issue 2, Special Issue of the 31st European Conference on Object-Oriented Programming (ECOOP 2017)


Abstract
This artifact provides the full mechanization in FCSL of the developments in the companion paper, "Concurrent Data Structures Linked in Time". In the latter, we propose a new method, based on a separation-style logic, for reasoning about concurrent objects with such linearization points. We embrace the dynamic nature of linearization points, and encode it as part of the data structure's auxiliary state, so that it can be dynamically modified in place by auxiliary code, as needed when some appropriate run-time event occurs. We illustrate the method by verifying (mechanically in FCSL) an intricate optimal snapshot algorithm due to Jayanti, as well as some clients. FCSL is the first completely formalized framework for mechanized verification of full functional correctness of fine-grained concurrent programs. It is implemented as an embedded domain-specific language (DSL) in the dependently-typed language of the Coq proof assistant, and is powerful enough to reason about programming features such as higher-order functions and local thread spawning. By incorporating a uniform concurrency model, based on state-transition systems and partial commutative monoids, FCSL makes it possible to build proofs about concurrent libraries in a thread-local, compositional way, thus facilitating scalability and reuse: libraries are verified just once, and their specifications are used ubiquitously in client-side reasoning.

Cite as

Germán Andrés Delbianco, Ilya Sergey, Aleksandar Nanevski, and Anindya Banerjee. Concurrent Data Structures Linked in Time (Artifact). In Special Issue of the 31st European Conference on Object-Oriented Programming (ECOOP 2017). Dagstuhl Artifacts Series (DARTS), Volume 3, Issue 2, pp. 4:1-4:4, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2017)


Copy BibTex To Clipboard

@Article{delbianco_et_al:DARTS.3.2.4,
  author =	{Delbianco, Germ\'{a}n Andr\'{e}s and Sergey, Ilya and Nanevski, Aleksandar and Banerjee, Anindya},
  title =	{{Concurrent Data Structures Linked in Time (Artifact)}},
  pages =	{4:1--4:4},
  journal =	{Dagstuhl Artifacts Series},
  ISSN =	{2509-8195},
  year =	{2017},
  volume =	{3},
  number =	{2},
  editor =	{Delbianco, Germ\'{a}n Andr\'{e}s and Sergey, Ilya and Nanevski, Aleksandar and Banerjee, Anindya},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DARTS.3.2.4},
  URN =		{urn:nbn:de:0030-drops-72850},
  doi =		{10.4230/DARTS.3.2.4},
  annote =	{Keywords: separation logic, linearization Points, concurrent snapshots, FCSL}
}
Document
Concurrent Data Structures Linked in Time

Authors: Germán Andrés Delbianco, Ilya Sergey, Aleksandar Nanevski, and Anindya Banerjee

Published in: LIPIcs, Volume 74, 31st European Conference on Object-Oriented Programming (ECOOP 2017)


Abstract
Arguments about correctness of a concurrent data structure are typically carried out by using the notion of linearizability and specifying the linearization points of the data structure's procedures. Such arguments are often cumbersome as the linearization points' position in time can be dynamic (depend on the interference, run-time values and events from the past, or even future), non-local (appear in procedures other than the one considered), and whose position in the execution trace may only be determined after the considered procedure has already terminated. In this paper we propose a new method, based on a separation-style logic, for reasoning about concurrent objects with such linearization points. We embrace the dynamic nature of linearization points, and encode it as part of the data structure's auxiliary state, so that it can be dynamically modified in place by auxiliary code, as needed when some appropriate run-time event occurs. We name the idea linking-in-time, because it reduces temporal reasoning to spatial reasoning. For example, modifying a temporal position of a linearization point can be modeled similarly to a pointer update in separation logic. Furthermore, the auxiliary state provides a convenient way to concisely express the properties essential for reasoning about clients of such concurrent objects. We illustrate the method by verifying (mechanically in Coq) an intricate optimal snapshot algorithm due to Jayanti, as well as some clients.

Cite as

Germán Andrés Delbianco, Ilya Sergey, Aleksandar Nanevski, and Anindya Banerjee. Concurrent Data Structures Linked in Time. In 31st European Conference on Object-Oriented Programming (ECOOP 2017). Leibniz International Proceedings in Informatics (LIPIcs), Volume 74, pp. 8:1-8:30, Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2017)


Copy BibTex To Clipboard

@InProceedings{delbianco_et_al:LIPIcs.ECOOP.2017.8,
  author =	{Delbianco, Germ\'{a}n Andr\'{e}s and Sergey, Ilya and Nanevski, Aleksandar and Banerjee, Anindya},
  title =	{{Concurrent Data Structures Linked in Time}},
  booktitle =	{31st European Conference on Object-Oriented Programming (ECOOP 2017)},
  pages =	{8:1--8:30},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-035-4},
  ISSN =	{1868-8969},
  year =	{2017},
  volume =	{74},
  editor =	{M\"{u}ller, Peter},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ECOOP.2017.8},
  URN =		{urn:nbn:de:0030-drops-72558},
  doi =		{10.4230/LIPIcs.ECOOP.2017.8},
  annote =	{Keywords: Separation logic, Linearization Points, Concurrent snapshots, FCSL}
}
Document
Programming Language Abstractions for Modularly Verified Distributed Systems

Authors: James R. Wilcox, Ilya Sergey, and Zachary Tatlock

Published in: LIPIcs, Volume 71, 2nd Summit on Advances in Programming Languages (SNAPL 2017)


Abstract
Distributed systems are rarely developed as monolithic programs. Instead, like any software, these systems may consist of multiple program components, which are then compiled separately and linked together. Modern systems also incorporate various services interacting with each other and with client applications. However, state-of-the-art verification tools focus predominantly on verifying standalone, closed-world protocols or systems, thus failing to account for the compositional nature of distributed systems. For example, standalone verification has the drawback that when protocols and their optimized implementations evolve, one must re-verify the entire system from scratch, instead of leveraging compositionality to contain the reverification effort. In this paper, we focus on the challenge of modular verification of distributed systems with respect to high-level protocol invariants as well as for low-level implementation safety properties. We argue that the missing link between the two is a programming paradigm that would allow one to reason about both high-level distributed protocols and low-level implementation primitives in a single verification-friendly framework. Such a link would make it possible to reap the benefits from both the vast body of research in distributed computing, focused on modular protocol decomposition and consistency properties, as well as from the recent advances in program verification, enabling construction of provably correct systems implementations. To showcase the modular verification challenges, we present some typical scenarios of decomposition between a distributed protocol and its implementations. We then describe our ongoing research agenda, in which we are attempting to address the outlined problems by providing a typing discipline and a set of domain-specific primitives for specifying, implementing and verifying distributed systems. Our approach, mechanized within a proof assistant, provides the means of decomposition necessary for modular proofs about distributed protocols and systems.

Cite as

James R. Wilcox, Ilya Sergey, and Zachary Tatlock. Programming Language Abstractions for Modularly Verified Distributed Systems. In 2nd Summit on Advances in Programming Languages (SNAPL 2017). Leibniz International Proceedings in Informatics (LIPIcs), Volume 71, pp. 19:1-19:12, Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2017)


Copy BibTex To Clipboard

@InProceedings{wilcox_et_al:LIPIcs.SNAPL.2017.19,
  author =	{Wilcox, James R. and Sergey, Ilya and Tatlock, Zachary},
  title =	{{Programming Language Abstractions for Modularly Verified Distributed Systems}},
  booktitle =	{2nd Summit on Advances in Programming Languages (SNAPL 2017)},
  pages =	{19:1--19:12},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-032-3},
  ISSN =	{1868-8969},
  year =	{2017},
  volume =	{71},
  editor =	{Lerner, Benjamin S. and Bod{\'\i}k, Rastislav and Krishnamurthi, Shriram},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SNAPL.2017.19},
  URN =		{urn:nbn:de:0030-drops-71266},
  doi =		{10.4230/LIPIcs.SNAPL.2017.19},
  annote =	{Keywords: Distributed systems, program verification, distributed protocols, domain-specific languages, type systems, dependent types, program logics.}
}
Questions / Remarks / Feedback
X

Feedback for Dagstuhl Publishing


Thanks for your feedback!

Feedback submitted

Could not send message

Please try again later or send an E-mail