Theoretical questions in Distributed Computing

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Examples of distributed systems [closed]

Would you please give me some examples of real distributed systems in the world that care about the performance of end-user besides the end-system. For example in Amazon Elastic Compute Cloud or Sun ...
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60 views

Problems needs solutions in Distributed computing? [duplicate]

This is same as question. The answer for the question is 3 years old. Since the old topics will be quickly outdated or solved and new research problems arises, it would be great to know the latest ...
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61 views

How to simulate sequential registers from causal ones?

Background: In distributed shared memory (DSM) model, the problem of register simulations/constructions is to simulate registers with certain characteristic out of registers with weaker features. For ...
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51 views

Recently Practical Problems for a Distributed system model

I've read the article of Grosu and Chronopoulos in 2005. For the load balancing problem and the model of distributed system in this article, I am seeking for recently practical problems and real ...
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1answer
69 views

Results about computability power or limitations of shared read/write registers

I want to know more results about the computability power or limitations of shared $\texttt{read/write}$ registers/objects in distributed/concurrent computing theory. Two typical examples are: [1]. ...
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In what sense, does a safe register exist?

In the paper "On Interprocess Communication", the author Leslie Lamport have developed a formalism for interprocess communication via shared registers based on lower-level, non-atomic operations and ...
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67 views

Lower bounds and impossibility results for distributed transactions

I am studying on distributed transactions, mainly on the correctness criteria (e.g., serializability (SR) and snapshot isolation (SI) in replicated settings) and their implementations. To avoid ...
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154 views

What are the major research issues in distributed transactions?

Background: Transaction processing has been a traditional research topic in database theory. Nowadays distributed transactions are popularized by the large-scale distributed storage systems which ...
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44 views

What are the differences between data partition and data replication regarding distributed transaction?

For a large-scale distributed database (or storage) system, data is often partitioned (wiki) (a.k.a sharding) and/or replicated (wiki) across different nodes. Roughly speaking, data partition splits ...
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118 views

State of the art algorithms for community detection in graphs

Is anyone aware of the must read papers to get knowledge of the most recent algorithms and method for community detection in graphs, especially those that represent social networks?
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43 views

Proof of causal multicast algorithm?

I'm reading Causal Memory: Denitions, Implementation and Programming and trying to get through the proof of liveliness of the algorithm around the middle of page 9, and I'm not really following it. ...
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1answer
68 views

The proof of P2b in Paxos made simple

I am reading Paxos Made Simple. I am quite confused about the proof of P2b. It said We would make the proof easier by using induction on n, so we can prove that proposal number n has value v under ...
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What are some natural problems that we can quickly find a solution to using massive parallelism but not a canonical solution?

For many problems, more than one output is acceptable. For instance, the problem of finding an assignment that satisfies a boolean formula. If randomness buys us something then it could be that it ...
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What is the resolution of the apparent contradiction in the Practical Byzantine Fault Tolerance paper?

This question refers to the paper by Miguel Castro and Barbara Liskov. On Page 4, the fourth paragraph of 4.2, it says "the primary... multicasts a pre-prepare message with m piggybacked to all the ...
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216 views

Correctness proofs of classic Paxos and Fast Paxos

I am reading the "Fast Paxos" paper by Leslie Lamport and get stuck with the correctness proofs of both classic Paxos and Fast Paxos. For consistency, the value $v$ picked by the coordinator in phase ...
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116 views

What is the significance of regarding the mutual exclusion problem as a problem of physics?

In the description of his own paper "On Interprocess Communication" [Distributed Computing 1, 2 (1986), 77-101], Leslie Lamport wrote Most computer scientists regard synchronization problems, such ...
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115 views

Concurrent data structures vs. Distributed data structures

In the context of multi-processor/multi-threaded systems, there are plenty of well-studied concurrent data structures, including stacks, queues, linked lists, etc. Here is an excellent survey on ...
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188 views

Job scheduling: minimizing number of reads

Consider the following scheduling problem: input: set of computations $C = \{c_1, ..., c_n\}$ set of computing nodes $P = \{p_1, ..., p_n\}$ Dependency graph $D$ between jobs (DAG) $(c_i,c_j)$ ...
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Election algorithm with unreliable messages and a certain timestamp

I am struggling to get a correct algorithm for a leader election algorithm in a distributed system. My assumptions are as follows: Messages are sent unreliably with an at-most-once sending Nodes are ...
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2answers
194 views

What does it mean for CvRDT replicas to transmit their state “infinitely often”?

In Shapiro et al.'s SSS '11 paper on Conflict-Free Replicated Data Types for eventual consistency of distributed replicated objects, they describe a system model in which replicas transmit their state ...
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Totally ordered multicast with Lamport timestamps

I'm studying Distributed Systems and synchronization and I didn't catch this solution of totally ordered multicast with Lamport timestamps. I read that it doesn't need ack to deliver a message to the ...
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40 views

Are the sets of executions of data-race free programs equal, when run on causal memory and on sequentially consistent memory respectively?

In the paper "Causal Memory: Definitions, Implementations, and Programming (Distributed Computing [DC] 1995)", the authors present a formal definition of causal memory, an abstraction of distributed ...
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320 views

Why is linearizability a safety property and why are safety properties closed sets?

In Chapter 13 "Atomic Objects" of the book "Distributed Algorithms" by Nancy Lynch, linearizability (also known as atomicity) is proved to be a safety property. That is to say, its corresponding trace ...
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What is the staleness in this execution of the $k$-atomic multi-writer register construction from $k$-atomic single-writer ones?

Background: $K$-atomicity is a consistency condition meaning that a read operation can return one of the values written by the last $k$ preceding writes in an order consistent with real time. It is a ...
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What is the advantage of designing deterministic distributed algorithms?

Distributed algorithms that are resilient to failures can either be deterministic or probabilistic. Take for example the consensus problem. Paxos is deterministic in the sense that given the ...
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2PC with URBcast

Two phase commitment can be used for distributed transaction commitment. But it is consider as a blocking protocol when we used it with a best effort broadcast (BEBcast). My first question is, can we ...
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Atomic snapshot algorithms on tree-structured shared registers

Background: Atomic snapshot memory is a shared memory partitioned into words written (updated) by individual processes, or instantaneously read (scanned) in its entirety. The Gang of Six algorithm ...
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Should the Schedule of ``High-level Operations'' Respect the Linearizability of ``Low-level Operations'' in Proof of Simulation Algorithm?

Backgroud I am reading Chapter 10 ``Fault-Tolerant Simulations of Read/Write Objects'' of the Book Distributed Computing (by Hagit Attiya & Jennifer Welch). Specifically, in section 10.2.3, it ...
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326 views

Is This Scheduling Problem NP-Hard?

The scheduling problem (arising from distributed computing) is defined as a decision problem as follows: Instance: A trace is comprised of $n$ processes histories (denoted $p_0, p_1, \ldots, ...
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175 views

How to Define and Implement (Single-Writer) K-Atomic Snapshot Object?

I am trying to motivate, define, and implement $K$-atomic snapshot object. To this aim, I first give some basic definitions on atomic snapshot object and $K$-atomic object. Then, I will give my ...
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282 views

Termination of the Bellman-Ford algorithm in asynchronous distributed model

I'm looking for an algorithm to compute the BFS tree of a graph rooted in the leader processor $r$ in the asynchronous distributed model. The only requirement is $O(D)$ time complexity, where $D$ ...
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84 views

bounds in centralized and distributed

If we know some lower bound of the solution of a problem in centralized setting, what can we say about the lower bound in a distributed setting?
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Is linearizability equivalent to consensus problem?

In the introduction of this paper Eventually Linearizable Shared Objects (PODC'10), the authors have presented the following statement without references: Linearizability, however, can be achieved ...
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Distributed file storage system - theoretical approaches

What are the main theoretical approaches to a distributed file storage system that allows files to be stored across a network of nodes, assuring their availability in case a node randomly loses ...
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Order of operations in 2 and 3 phase atomic commit protocols

I am currently reading through this http://research.microsoft.com/en-us/people/philbe/chapter7.pdf chapter about distributed recovery. The chapter focuses on 2 phase atomic commit (2PC) and 3 phase ...
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463 views

Is there a list of canonical problems in distributed systems?

Last week, I was reading again Leslie's Lamport's 1982 trasncript of a conference he gave about Solved Problems, Unsolved Problems and Non-Problems in Concurrency. The paper is easily readable, but ...
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Who said: “There is no central arbiter of truth in open distributed systems.”

Can anyone give me a reference to the origin of the statement "There is no central arbiter of truth in open distributed systems." Possibly it was Carl Hewitt in "The Challenge of Open Systems" Byte ...
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How to formally model the “hesitation” in the hat-guessing puzzle and prove it by mathematical induction?

The following question was first presented in MATHEMATICS of StackExchange. With a simple description at first sight, it has far-reaching consequences on plenty of recent and advanced theories, such ...
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Distributed algorithms on sets

Given a connected arbitrary network $G = (V,E)$, where $V$ is a set of nodes (processors) and $E$ is the set of edges between the nodes. Each node $v _i$ is assigned a non-empty set $S(v _i)$, where ...
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Why is the consensus problem so important in distributed computing?

In distributed computing, the consensus problem seems to be one of the central topics which has attracted intensive research. In particular, the paper "Impossibility of Distributed Consensus with One ...
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Does mathematical model for conccurent computations exist?

Turing machines can represent any computation. Can they also represent concurrent computations? Eg. multiple computations that can happen at the same time? If yes, how are the concurrent computations ...
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106 views

Lower bound for orienting an asynchronous ring?

We require a lower message complexity bound of an asynchronous distributed algorithm that do the following: Given a undirected ring, with $n$ vertices, we want to let each node direct its edges to ...
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229 views

Model checking Paxos

I have implemented consensus algorithm (based on Paxos). I have added some random test cases and it seems fine. To be sure, I want to do testing via model checking. I couldn't find a correct article ...
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Existence of “colouring matrices” — a generalisation

This is a generalisation of the following post: Existence of "colouring matrices". As the base case turned out to be fairly straightforward (in essence, precisely equal to the existence of Sperner ...
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Existence of “colouring matrices”

Edit: there is now a follow-up question related to this post. Definitions Let $c$ and $k$ be integers. We use the notation $[i] = \{1,2,...,i\}$. A $c \times c$ matrix $M = (m_{i,j})$ is said to ...
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558 views

Efficient synchronization of two instances of an ordered list

What data structure or algorithm can be used to efficiently synchronize two nearly identical ordered lists? Two offline systems start with the same ordered list and each edit, insert, delete and move ...
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140 views

Minimal bandwidth required to synchronize two sets of values

We consider two computers who possess two sets of fixed-size values (ie. $k$-bit numbers for some constant $k$), and we assume that the two sets have a large overlap (ie. a large proportion of the ...
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370 views

How to understand the “Availability” of the CAP theorem?

As we know, in the CAP theorem, "A" means "Availability". On wikipedia, the explanation of "Availability" is: Availability: a guarantee that every request receives a response about whether it ...
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FloodSet in general networks

I would like to ask how could someone modify FloodSet algorithm to work in a general network, where process failures happen..Is it possible for it to work if a "crucial" [1] failure happens? [1]: As ...
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115 views

Honest Majority unconditional coinflipping without private channels

All communication is assumed to be by the parties taking turns making authenticated broadcasts. Is there a way for $n$ parties, each with access to ideal local randomness, to jointly choose ...