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16
Using Multiple Hash Functions to Improve IP Lookups
 IN PROCEEDINGS OF IEEE INFOCOM
, 2000
"... High performance Internet routers require a mechanism for very efficient IP address lookups. Some techniques used to this end, such as binary search on levels, need to construct quickly a good hash table for the appropriate IP prefixes. In this paper we describe an approach for obtaining good hash ..."
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Cited by 68 (11 self)
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High performance Internet routers require a mechanism for very efficient IP address lookups. Some techniques used to this end, such as binary search on levels, need to construct quickly a good hash table for the appropriate IP prefixes. In this paper we describe an approach for obtaining good hash tables based on using multiple hashes of each input key (which is an IP address). The methods we describe are fast, simple, scalable, parallelizable, and flexible. In particular, in instances where the goal is to have one hash bucket fit into a cache line, using multiple hashes proves extremely suitable. We provide a general analysis of this hashing technique and specifically discuss its application to binary search on levels.
BALANCED ALLOCATIONS: THE HEAVILY LOADED CASE
, 2006
"... We investigate ballsintobins processes allocating m balls into n bins based on the multiplechoice paradigm. In the classical singlechoice variant each ball is placed into a bin selected uniformly at random. In a multiplechoice process each ball can be placed into one out of d ≥ 2 randomly selec ..."
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Cited by 57 (7 self)
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We investigate ballsintobins processes allocating m balls into n bins based on the multiplechoice paradigm. In the classical singlechoice variant each ball is placed into a bin selected uniformly at random. In a multiplechoice process each ball can be placed into one out of d ≥ 2 randomly selected bins. It is known that in many scenarios having more than one choice for each ball can improve the load balance significantly. Formal analyses of this phenomenon prior to this work considered mostly the lightly loaded case, that is, when m ≈ n. In this paper we present the first tight analysis in the heavily loaded case, that is, when m ≫ n rather than m ≈ n. The best previously known results for the multiplechoice processes in the heavily loaded case were obtained using majorization by the singlechoice process. This yields an upper bound of the maximum load of bins of m/n + O ( √ m ln n/n) with high probability. We show, however, that the multiplechoice processes are fundamentally different from the singlechoice variant in that they have “short memory. ” The great consequence of this property is that the deviation of the multiplechoice processes from the optimal allocation (that is, the allocation in which each bin has either ⌊m/n ⌋ or ⌈m/n ⌉ balls) does not increase with the number of balls as in the case of the singlechoice process. In particular, we investigate the allocation obtained by two different multiplechoice allocation schemes,
Differential equation approximations for Markov chains, manuscript
, 2005
"... We formulate some simple conditions under which a Markov chain may be approximated by the solution to a differential equation, with quantifiable error probabilities. The role of a choice of coordinate functions for the Markov chain is emphasised. The general theory is illustrated in three examples: ..."
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Cited by 42 (1 self)
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We formulate some simple conditions under which a Markov chain may be approximated by the solution to a differential equation, with quantifiable error probabilities. The role of a choice of coordinate functions for the Markov chain is emphasised. The general theory is illustrated in three examples: the classical stochastic epidemic, a population process model with fast and slow variables, and corefinding algorithms for large random hypergraphs. 1
On Balls and Bins with Deletions
 In Proc. of the RANDOM'98
, 1998
"... Microsystems. The views and conclusions contained here are those of the authors and should not be interpreted as necessarily representing the official policies or ..."
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Cited by 18 (1 self)
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Microsystems. The views and conclusions contained here are those of the authors and should not be interpreted as necessarily representing the official policies or
The Asymptotics of Selecting the Shortest of Two, Improved
 UNIVERSITY OF ILLINOIS
, 1999
"... We investigate variations of a novel, recently proposed load balancing scheme based on small amounts of choice. The static setting is modeled as a ballsandbins process. The balls are sequentially placed into bins, with each ball selecting d bins randomly and going to the bin with the fewest balls. ..."
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Cited by 17 (7 self)
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We investigate variations of a novel, recently proposed load balancing scheme based on small amounts of choice. The static setting is modeled as a ballsandbins process. The balls are sequentially placed into bins, with each ball selecting d bins randomly and going to the bin with the fewest balls. A similar dynamic setting is modeled as a scenario where tasks arrive as a Poisson process at a bank of FIFO servers and queue at one for service. Tasks probe a small random sample of servers in the bank and queue at the server with the fewest tasks. Recently
Cuckoo hashing: Further analysis
, 2003
"... We consider cuckoo hashing as proposed by Pagh and Rodler in 2001. We show that the expected construction time of the hash table is O(n) as long as the two open addressing tables are each of size at least (1 #)n,where#>0andn is the number of data points. Slightly improved bounds are obtained for ..."
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Cited by 17 (1 self)
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We consider cuckoo hashing as proposed by Pagh and Rodler in 2001. We show that the expected construction time of the hash table is O(n) as long as the two open addressing tables are each of size at least (1 #)n,where#>0andn is the number of data points. Slightly improved bounds are obtained for various probabilities and constraints. The analysis rests on simple properties of branching processes.
Recovery time of dynamic allocation processes
 IN PROCEEDINGS OF THE 10TH ANNUAL ACM SYMPOSIUM ON PARALLEL ALGORITHMS AND ARCHITECTURES, PUERTO VALLARTA, MEXICO, 28 JUNE–2
, 1998
"... Many distributed protocols arising in applications in online load balancing and dynamic resource allocation can be modeled by dynamic allocation processes related to the “balls into bin” problems. Traditionally the main focus of the research on dynamic allocation processes is on verifying whether a ..."
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Cited by 12 (3 self)
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Many distributed protocols arising in applications in online load balancing and dynamic resource allocation can be modeled by dynamic allocation processes related to the “balls into bin” problems. Traditionally the main focus of the research on dynamic allocation processes is on verifying whether a given process is stable, and if so, on analyzing its behavior in the limit (i.e., after sufficiently many steps). Once we know that the process is stable and we know its behavior in the limit, it is natural to analyze its recovery time, which is the time needed by the process to recover from any arbitrarily bad situation and to arrive very closely to a stable (i.e., a typical) state. This investigation is important to provide assurance that even if at some stage the process has reached a highly undesirable state, we can predict with high confidence its behavior after the estimated recovery time. In this paper we present a genera / framework to study the recovery time of discretetime dynamic allocation processes. We model allocation processes by suitably chosen ergodic Markov chains. For a given Markov chain we apply path coupling arguments to bound its convergence rates to the stationary distribution, which directly yields the estimation of the recovery time of the corresponding allocation process. Our coupling approach provides in a relatively simple way an accurate prediction of the recovery time. In particular, we show that our method can be applied to significantly improve estimations of the recovery time for various allocation processes related to allocations of balls into bins, and for the edge orientation problem studied before by Ajtai et al.
On ZoneBalancing of PeertoPeer Networks: Analysis of Random Node Join
, 2004
"... Balancing peertopeer graphs, including zonesize distributions, has recently become an important topic of peertopeer (P2P) research [1], [2], [6], [19], [31], [36]. To bring analytical understanding into the various peerjoin mechanisms, we study how zonebalancing decisions made during the initi ..."
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Cited by 11 (4 self)
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Balancing peertopeer graphs, including zonesize distributions, has recently become an important topic of peertopeer (P2P) research [1], [2], [6], [19], [31], [36]. To bring analytical understanding into the various peerjoin mechanisms, we study how zonebalancing decisions made during the initial sampling of the peer space a#ect the resulting zone sizes and derive several asymptotic results for the maximum and minimum zone sizes that hold with high probability.
On the power of two choices: balls and bins in continuous time
, 2005
"... Suppose that there are n bins, and balls arrive in a Poisson process at rate λn, whereλ>0 is a constant. Upon arrival, each ball chooses a fixed number d of random bins, and is placed into one with least load. Balls have independent exponential lifetimes with unit mean. We show that the system conve ..."
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Cited by 11 (2 self)
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Suppose that there are n bins, and balls arrive in a Poisson process at rate λn, whereλ>0 is a constant. Upon arrival, each ball chooses a fixed number d of random bins, and is placed into one with least load. Balls have independent exponential lifetimes with unit mean. We show that the system converges rapidly to its equilibrium distribution; and when d ≥ 2, there is an integervalued function md(n) = ln ln n/ln d + O(1) such that, in the equilibrium distribution, the maximum load of a bin is concentrated on the two values md(n) and md(n) − 1, with probability tending to 1, as n →∞. We show also that the maximum load usually does not vary by more than a constant amount from ln ln n/ln d, even over quite long periods of time. 1. Introduction. Ballsandbins processes have been useful for modeling and analyzing a wide range of problems, in discrete mathematics, computer science and communication theory, and, in particular, for problems which involve load sharing, see, for example, [4, 5, 12, 15–17, 22]. Here is one central result, from [3]. Let d be a fixed integer at least 2. Suppose that there are n bins, and n balls arrive
Enhancing the effective utilisation of Grid clusters by exploiting OnLine Performability Analysis
"... In Grid applications the heterogeneity and potential failures of the computing infrastructure poses significant challenges to efficient scheduling. Performance models have been shown to be useful in providing predictions on which schedules can be based [1, 2] and most such techniques can also take a ..."
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Cited by 9 (6 self)
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In Grid applications the heterogeneity and potential failures of the computing infrastructure poses significant challenges to efficient scheduling. Performance models have been shown to be useful in providing predictions on which schedules can be based [1, 2] and most such techniques can also take account of failures and degraded service. However, when several alternative schedules are to be compared it is vital that the analysis of the models does not become so costly as to outweigh the potential gain of choosing the best schedule. Moreover, it is vital that the modelling approach can scale to match the size and complexity of realistic applications. In this