scholarly journals On stabilizability of fluid multi-server polling systems with setups

2018 ◽  
pp. 26-34
Author(s):  
Alexey Matveev
Keyword(s):  
Fluid Model ◽  
Round Robin ◽  
Time Measurement ◽  
Polling Systems ◽  
Polling System ◽  
Full Information ◽  
Time Invariant ◽  
Multi Server ◽  
Necessity Part ◽  
Service Protocol

A time-invariant fluid model of a polling system is considered. It consists of finitely many servers and buffers with unlimited sizes. The buffers receive inflows of work from the outside, work leaves the system after processing by a server. Every server works only with buffers from an associated zone of service, which may overlap for various servers, is able to serve at most one buffer at a time and so has to switch, from time to time, among buffers, the switch-over times are nonzero. We present a criterion for existence of a scheduling and service protocol that makes the system stable in the sense that the total amount of work in the buffers remains bounded as time progresses. The necessity part of this result is concerned with the widest class of protocols, including dynamic ones that are centralized and have access to the full information about the events in the system. Meanwhile, we show that every stabilizable system can be stabilized in a fully decentralized fashion via a simple static protocol, e.g., by a protocol that is based on independent round robin scheduling of the servers and for every server, employs only time measurement.

scholarly journals M/G/∞ POLLING SYSTEMS WITH RANDOM VISIT TIMES

2007 ◽  
Vol 22 (1) ◽  
pp. 81-106 ◽  
Author(s):  
M. Vlasiou ◽  
U. Yechiali
Keyword(s):  
Service Time ◽  
Probability Generating Function ◽  
Expected Value ◽  
Polling Systems ◽  
Service Time Distribution ◽  
Polling System ◽  
Stieltjes Transform ◽  
Polling Model ◽  
Queue Lengths ◽  
Number Of Customers

We consider a polling system where a group of an infinite number of servers visits sequentially a set of queues. When visited, each queue is attended for a random time. Arrivals at each queue follow a Poisson process, and the service time of each individual customer is drawn from a general probability distribution function. Thus, each of the queues comprising the system is, in isolation, anM/G/∞-type queue. A job that is not completed during a visit will have a new service-time requirement sampled from the service-time distribution of the corresponding queue. To the best of our knowledge, this article is the first in which anM/G/∞-type polling system is analyzed. For this polling model, we derive the probability generating function and expected value of the queue lengths and the Laplace–Stieltjes transform and expected value of the sojourn time of a customer. Moreover, we identify the policy that maximizes the throughput of the system per cycle and conclude that under the Hamiltonian-tour approach, the optimal visiting order isindependentof the number of customers present at the various queues at the start of the cycle.

A Comparison of Fair Sharing Algorithms for Regulating Search as a Service API

2021 ◽  
Vol 8 (6) ◽  
pp. 16-34
Author(s):  
Sikha Bagui ◽  
Evorell Fridge
Keyword(s):  
Search Engine ◽  
Round Robin ◽  
Computer Networking ◽  
Single Server ◽  
Equitable Access ◽  
Token Bucket ◽  
Multi Server ◽  
Fair Balance ◽  
Fair Sharing ◽  
Deficit Round Robin

Providers of a Search as a Service (SaaS) environment must ensure that their users will not monopolize the service or use more than their fair share of resources. Fair sharing algorithms have long been used in computer networking to balance access to a router or switch, and some of these algorithms have also been applied to the control of queries submitted to search engine APIs. If a search query’s execution cost can be reliably estimated, fair sharing algorithms can be applied to the input of a SaaS API to ensure everyone has equitable access to the search engine. The novelty of this paper lies in presenting a Single-Server Max-Min Fair Deficit Round Robin algorithm, a modified version of the Multi-Server Max-Min Fair Deficit Round Robin algorithm. The Single-Server Max-Min Fair Deficit Round Robin algorithm is compared to three other fair sharing algorithms, token-bucket, Deficit Round Robin (DRR), and Peng and Plale’s [1] Modified Deficit Round Robin (MDRR) in terms of three different usage scenarios, balanced usage, unbalanced usage as well as an idle client usage, to determine which is the most suitable fair sharing algorithm for use in regulating traffic to a SaaS API. This research demonstrated that the Single-Server Max-Min Fair DRR algorithm provided the highest throughput of traffic to the search engine while also maintaining a fair balance of resources among clients by re-allocating unused throughput to clients with saturated queues so a max-min allocation was achieved.

A Protocol for Anonymous and Accurate E-Polling

2007 ◽  
pp. 180-198
Author(s):  
Danilo Bruschi ◽  
Andrea Lanzi ◽  
Igor Naiq Fovino
Keyword(s):  
Security Requirements ◽  
Polling Systems ◽  
Polling System ◽  
Fundamental Component ◽  
Simple Protocol ◽  
Public Debates

E-polling systems are a fundamental component of any E-democracy system as they represent the most appropriate tool for fostering citizens participation to public debates. Contrarily to e-voting protocols, they are characterized by less stringent security requirements and they can also tolerate errors affecting a small percentage of votes, without compromising of the final result. Thus, their realization can be effectively pursued supporting the diffusion of e-democracy. In this paper we propose a simple protocol for an accurate and anonymous e-polling system. Such a protocol satisfies, among the others, the following properties: a vote cannot be altered, duplicated, or removed without being detected, votes remain anonymous. Moreover voters will be able to measure the level of trust of the process by verifying that their own votes have been correctly counted.

scholarly journals Stability of multi-server polling system with server limits

2011 ◽  
Vol 68 (3-4) ◽  
pp. 229-235 ◽  
Author(s):  
Nelson Antunes ◽  
Christine Fricker ◽  
James Roberts
Keyword(s):  
Polling System ◽  
Multi Server

POLLING SYSTEMS WITH TWO-PHASE GATED SERVICE

2008 ◽  
Vol 22 (4) ◽  
pp. 623-651 ◽  
Author(s):  
R. D. van der Mei ◽  
J. A. C. Resing
Keyword(s):  
Waiting Time ◽  
Branching Processes ◽  
Heavy Traffic ◽  
Polling Systems ◽  
Polling System ◽  
Two Phase ◽  
General Parameter ◽  
Multitype Branching Processes ◽  
Poisson Arrivals ◽  
Gated Service

We study an asymmetric cyclic polling system with Poisson arrivals, general service-time and switch-over time distributions, and so-called two-phase gated service at each queue, an interleaving scheme that aims to enforce some level of “fairness” among the different customer classes. For this model, we use the classical theory of multitype branching processes to derive closed-form expressions for the Laplace–Stieltjes transform of the waiting-time distributions when the load tends to 1, in a general parameter setting and under proper heavy-traffic scalings. This result is strikingly simple and provides new insights in the behavior of two-phase polling systems. In particular, the result provides insight in the waiting-time performance and the trade-off between efficiency and fairness of two-phase gated polling compared to the classical one-phase gated service policy.

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