Verified Causal Broadcast with Liquid Haskell

Redmond, Patrick; Shen, Gan; Vazou, Niki; Kuper, Lindsey

doi:10.1145/3587216.3587222

Cited by 4 publications

(3 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A Birman's CRB library is causally consistent if it verifies the CRB properties for all its possible executions. Examples of the difficulty of formal verification of Birman's CRB libraries can be seen in [23] and [24]. In both libraries, the causal delivery property needs to be verified locally in every process because of the lack of global cDeliver timestamping.…”

Section: Problem Statementmentioning

confidence: 99%

“…In both libraries, the causal delivery property needs to be verified locally in every process because of the lack of global cDeliver timestamping. In both cases they need to build local histories assigning ad hoc local timestamps to cDeliver events in each process p. In [24], the timestamp of cDeliver of m in p is the value of the local clock when this event happened in p, while in [23], the timestamp of cDeliver of m is the value of the timestamp of the cBroadcast of m.…”

Section: Problem Statementmentioning

confidence: 99%

“…Besides the causal delivery property problems identified in the previous paragraph, the validity property of CRB that says that a correct sender of a message m always self-cDelivers m is also hard to prove. Because the cDeliver events are not timestamped, in [24] the cBroadcast and its corresponding self-cDeliver events are considered as only one atomic event. In [23] a cBroadcast primitive is proposed to broadcast a message to all processes except the sender, and hence their cBroadcast primitive does not generate a self-cDeliver event.…”

Section: Problem Statementmentioning

confidence: 99%

See 2 more Smart Citations

Timestamp system for causal broadcast communication

Muñoz-Fernández,

Arévalo-Viñuales,

de-las-Heras-Quirós

2024

J Supercomput

View full text Add to dashboard Cite

In unreliable asynchronous distributed systems with failures, achieving a causal view of the system across all processes is a challenging task. The Causal Reliable Broadcast (CRB) abstraction is used to solve this task. When CRB is implemented with algorithms that use logical vector clocks to timestamp broadcast events, the causal relationships between broadcast events can be detected with maximal accuracy. However, this timestamping mechanism used by CRB might not be useful for systems that need to reason about the causal relationships among both broadcast and delivery events. To address this challenge, the paper proposes a Causal Timestamp System (CTS) based on vector clocks that timestamps broadcast and delivery events capturing with maximal accuracy the causal relationships among those events. CTS simplifies the formal verification and testing of implementations of CRB algorithms based on CTS. Additionally, a new Global State Monitoring (GSM) algorithm is proposed, tailored to a distributed system that uses CRB with CTS. GSM enables finer-grained assessment of global states and application-dependent predicates of that system. We clarify these concepts with an IoT example.

show abstract

Section: Problem Statementmentioning

confidence: 99%

Section: Problem Statementmentioning

confidence: 99%

Section: Problem Statementmentioning

confidence: 99%

See 1 more Smart Citation

Timestamp system for causal broadcast communication

Muñoz-Fernández,

Arévalo-Viñuales,

de-las-Heras-Quirós

2024

J Supercomput

View full text Add to dashboard Cite

show abstract

Modeling and Verification of the Causal Broadcast Algorithm Using Colored Petri Nets

NamvariTazehkand,

Pashazadeh

2024

2024 Third International Conference on Distributed Computing and High Performance Computing (DCHPC)

View full text Add to dashboard Cite

Inductive Diagrams for Causal Reasoning

Castello,

Redmond,

Kuper

2024

Proc. ACM Program. Lang.

View full text Add to dashboard Cite

The Lamport diagram is a pervasive and intuitive tool for informal reasoning about “happens-before” relationships in a concurrent system. However, traditional axiomatic formalizations of Lamport diagrams can be painful to work with in a mechanized setting like Agda. We propose an alternative, inductive formalization — the causal separation diagram (CSD) — that takes inspiration from string diagrams and concurrent separation logic, but enjoys a graphical syntax similar to Lamport diagrams. Critically, CSDs are based on the idea that causal relationships between events are witnessed by the paths that information follows between them. To that end, we model “happens-before” as a dependent type of paths between events. The inductive formulation of CSDs enables their interpretation into a variety of semantic domains. We demonstrate the interpretability of CSDs with a case study on properties of logical clocks , widely-used mechanisms for reifying causal relationships as data. We carry out this study by implementing a series of interpreters for CSDs, culminating in a generic proof of Lamport’s clock condition that is parametric in a choice of clock. We instantiate this proof on Lamport’s scalar clock, on Mattern’s vector clock, and on the matrix clocks of Raynal et al. and of Wuu and Bernstein, yielding verified implementations of each. The CSD formalism and our case study are mechanized in the Agda proof assistant.

show abstract

Verified Causal Broadcast with Liquid Haskell

Cited by 4 publications

References 33 publications

Timestamp system for causal broadcast communication

Timestamp system for causal broadcast communication

Modeling and Verification of the Causal Broadcast Algorithm Using Colored Petri Nets

Inductive Diagrams for Causal Reasoning

Contact Info

Product

Resources

About