How Hard is Asynchronous Weight Reassignment? (Extended Version)

The performance of distributed storage systems deployed on wide-area networks can be improved using weighted (majority) quorum systems instead of their regular variants due to the heterogeneous performance of the nodes. A significant limitation of weighted majority quorum systems lies in their dependence on static weights, which are inappropriate for systems subject to the dynamic nature of networked environments. To overcome this limitation, such quorum systems require mechanisms for reassigning weights over time according to the performance variations. We study the problem of node weight reassignment in asynchronous systems with a static set of servers and static fault threshold. We prove that solving such a problem is as hard as solving consensus, i.e., it cannot be implemented in asynchronous failure-prone distributed systems. This result is somewhat counter-intuitive, given the recent results showing that two related problems -- replica set reconfiguration and asset transfer -- can be solved in asynchronous systems. Inspired by these problems, we present two versions of the problem that contain restrictions on the weights of servers and the way they are reassigned. We propose a protocol to implement one of the restricted problems in asynchronous systems. As a case study, we construct a dynamic-weighted atomic storage based on such a protocol. We also discuss the relationship between weight reassignment and asset transfer problems and compare our dynamic-weighted atomic storage with reconfigurable atomic storage.Comment: This is the extended version of a paper to appear at the 43rd IEEE International Conference on Distributed Computing Systems (ICDCS 2023

Fault Tolerance in Distributed Systems using Dynamic Vote Management

There are several fault tolerant protocols for managing replicated files in the event of network partitioning due to site or communication link failures. Previously there has been no software simulation of the voting protocols apart from just stochastic modeling. In this paper, we simulate and analyze the throughput of message transfer during the communication. We use various network topologies to compare the parameters such as throughput, no of packets received and sent during voting process .We have analyzed the effects of various packet properties. The analysis provides evidence for the conjecture that the grouping scheme is the optimal algorithm in the context of the voting protocols. We also compare the proposed genetic approach for voting assignment with random algorithm proposed by Akhil Kumar. This comparison shows that genetic voting assignment gives better availability than random algorithm

A Note on a Weighted Voting Experiment: Human Mistakes in Cooperative Games

We conducted a sensitivity analysis of results in weighted voting experiments by varying the following two features of the protocol by Montero et al. (2008): (a) the way subjects' roles are reassigned in each round (random versus semi-fixed roles) and (b) the number of proposals that subjects can approve simultaneously (multiple versus single approval). We found that the possibility of simultaneously approving many proposals (multiple approvals) may result in more confusion and mistakes by subjects than the case without such a possibility (single approval). We also found that frequencies of minimal winning coalitions (MWCs) observed under the protocol with semi-fixed roles and single approval are consistent with our hypothesis: each subject prefers a MWC in which his or her relative weight is larger, and the probability of each MWC occurring depends on a score in the social ordering determined by the Borda count, when there is no veto player

The WPATH Standards of Care: Their History and Importance in Advocating for Transgender Health

The World Professional Association for Transgender Health (WPATH) Standards of Care publication one most-often cited in the defense of increasing attacks on transgender rights to gender-affirming healthcare, as it is the reigning body of clinical guidelines and recommendations for the medical treatment of transgender and gender-diverse populations developed for application in a global context. This paper recounts the history of the WPATH organization––formerly called the Harry Benjamin International Gender Dysphoria Association––and the evolution of its Standards publication. In light of historical and recent attacks on gender-affirming care, an overview of the material implications of the Standards’ changes as they pertain to legal and healthcare protections is also provided

Population Protocols with Unordered Data

Population protocols form a well-established model of computation of passively mobile anonymous agents with constant-size memory. It is well known that population protocols compute Presburger-definable predicates, such as absolute majority and counting predicates. In this work, we initiate the study of population protocols operating over arbitrarily large data domains. More precisely, we introduce population protocols with unordered data as a formalism to reason about anonymous crowd computing over unordered sequences of data. We first show that it is possible to determine whether an unordered sequence from an infinite data domain has a datum with absolute majority. We then establish the expressive power of the "immediate observation" restriction of our model, namely where, in each interaction, an agent observes another agent who is unaware of the interaction

Population Protocols with Unordered Data

Population protocols form a well-established model of computation of passively mobile anonymous agents with constant-size memory. It is well known that population protocols compute Presburger-definable predicates, such as absolute majority and counting predicates. In this work, we initiate the study of population protocols operating over arbitrarily large data domains. More precisely, we introduce population protocols with unordered data as a formalism to reason about anonymous crowd computing over unordered sequences of data. We first show that it is possible to determine whether an unordered sequence from an infinite data domain has a datum with absolute majority. We then establish the expressive power of the immediate observation restriction of our model, namely where, in each interaction, an agent observes another agent who is unaware of the interaction.Comment: accepted at ICALP 202

A Note on a Weighted Voting Experiment: Human Mistakes in Cooperative Games

We conducted a sensitivity analysis of results in weighted voting experiments by varying the following two features of the protocol by Montero et al. (2008): (a) the way subjects' roles are reassigned in each round (random versus semi-fixed roles) and (b) the number of proposals that subjects can approve simultaneously (multiple versus single approval). We found that the possibility of simultaneously approving many proposals (multiple approvals) may result in more confusion and mistakes by subjects than the case without such a possibility (single approval). We also found that frequencies of minimal winning coalitions (MWCs) observed under the protocol with semi-fixed roles and single approval are consistent with our hypothesis: each subject prefers a MWC in which his or her relative weight is larger, and the probability of each MWC occurring depends on a score in the social ordering determined by the Borda count, when there is no veto player.weighted voting; experiment; cooperative game; mistakes; winning coalition

Explaining differences in environmental governance patterns between Canada, Italy and the United States.

The objective of the paper is to formulate a hypothesis that can help explain the different patterns of environmental governance in three countries: Canada and the United States (both federal states) and Italy (a decentralized unitary state). To that effect, we will make use of what is a robust theory of the assignment of powers in federal and decentralized unitary states on the role of competition as a driving force in shaping these assignments. The differing patterns of environmental governance we wish to explain are that most environmental policies are enacted and implemented by the national government in the United States, by provincial governments in Canada, and by both national and regional governments in Italy.