the three stages of data processing

... Page  The Three Principles of Data Center Infrastructure Design Choosing the Right Mix of Equipment Since the total spend for network infrastructure equipment is but a fraction of the entire data ... Infrastructure Design The Three Principles of Data Center Design When you understand the three principles of data center design, you are able to: • Lower your total cost of ownership Cabling and ... Prepare for the Future Power Requirements Business can optimize their data centers by selecting data center infrastructure solutions that work together By recognizing the value of the data center...

Ngày tải lên: 24/01/2014, 11:20

... finished product, then adjustments will have to be made to the product's design Similarly, market research, which examines the extent and nature of the demand for products, has the role of guiding product ... not only the result of product research, but is also influenced by testing and market research If the testing stage (after assembly and inspection) reveals unacceptable problems in the finished ... product sales, also serves to foster future sales by devising suitable advertising for the goods Thus the reality of consumer goods manufacturing goes well beyond a simple linear production process...

Ngày tải lên: 04/10/2012, 10:02

... nước mắt all the way mặt ,ví dụ :If you want to take it up with the boss ,I’ll support you all the way go wrong phạm sai lầm come into being(existing) xuất stand for đại diện the advantage over ... trung bridge control điều khiển từ buồng lái emergency control điều khiển ứng cấp the centralized control room (the control room) buồng điều khiển tập trung remote control điều khiển từ xa UMS ... This remote control system mainly consists of a synchro signal transmitter, a phase-sensitive rectifier, a preamplifier, a push-pull magnetic...

Ngày tải lên: 28/10/2013, 08:15

... itself both at the level of the immediate chromatin environment of the intergenic region, and also at the level of topological status of the DNA as a result of transcription of the adjacent genes ... DnaC [14] Rather the role of ATP in the reaction is to serve as a switch that controls the activity of the helicase The ATP bound form of DnaC severely inhibits the helicase activity of DnaB and ... by unwinding of this intrinsically less stable region of duplex [6] A further level of complexity arises from the fact that DnaA is a member of the AAA+ family of ATPases This class of protein...

Ngày tải lên: 07/03/2014, 21:20

Ngày tải lên: 05/06/2014, 12:05

... 0-7923-997 1-4 DATABASE ISSUES IN GEOGRAPHIC INFORMATION SYSTEMS, Nabil R Adam, Aryya Gangopadhyay ISBN: 0-7923-9924-2 THE FRACTAL STRUCTURE OF DATA REFERENCE Applications to the Memory Hierarchy ... The Kluwer International Series on ADVANCES IN DATABASE SYSTEMS Series Editor Ahmed K Elmagarmid PurdueUniversity West Lafayette, IN 47907 Other books in the Series: SEMANTIC ... No part of this eBook may be reproduced or transmitted in any form or by any means, electronic, mechanical, recording, or otherwise, without written consent from the Publisher Created in the United...

Ngày tải lên: 03/07/2014, 08:20

... THE FRACTAL STRUCTURE OF DATA REFERENCE viii First-Cut Performance Estimate Impact of Transient Data Access History Dependent Collection TRANSIENT AND PERSISTENT DATA ACCESS Transient ... (corresponding to θ = 0.35) Tradeoff of memory above and below the I/O interface Overview of free space collection results Distribution of time between track updates, for the user and system storage ... Distribution of probability density for the metric P: track image granularity Distribution of probability density for the metric P: cylinder image granularity Distribution of probability density for the...

Ngày tải lên: 03/07/2014, 08:20

... the average time until the next reference becomes unbounded There is no steady-state arrival rate This xvi THE FRACTAL STRUCTURE OF DATA REFERENCE modeling approach reflects the opposite of the ... practical applications of such results The focus of the applications examined in this book is on the portion of a computer system’s memory hierarchy that lies below the level of the “get” and “put” ... book Instead, the “meat” of the present book comes from the ability of the hierarchical reuse model to impose a mathematically tractable structure on important problems involving the operation...

Ngày tải lên: 03/07/2014, 08:20

... percent of the total requests are to data contained in the busiest ten percent of the tracks Since the beginning of the sorted list represents the best possible cache contents, we may apply the definition ... order of the time since the last reference to them— track at the MRU position the was used most recently, the track next on the list was used most recently before the MRU track, and so forth The ... the arrival rate of requests THE FRACTAL STRUCTURE OF DATA REFERENCE to a given track equals its probability of being referenced times the overall rate of requests) Given these assumptions, there...

Ngày tải lên: 03/07/2014, 08:20

... exact rather than approximate, then this presentation of the data should result in a variety of straight lines; the slope 10 THE FRACTAL STRUCTURE OF DATA REFERENCE of each line (in the chart’s ... complete the journey between towns, it must take tracks containing all types of data about the same amount of time to get from the top to the bottom ofthe LRU list Thus, ifwe wish to apply the hierarchical ... Based upon the idea of time scales that are mirror images of each other, we should expect that the short term track has the same probability of being referenced in the next seconds, as the long...

Ngày tải lên: 03/07/2014, 08:20

... share a common drawback: their scope of application excludes a substantial period of time at the beginning of the trace For the former, the time excluded is equal to τ; for the latter, a “warm up” ... intervals where the track is touched but there is no back end I/O The number of such intervals is given by the number of interval boundaries crossed by the front end (here again we make use of the fact ... averages of these three quantities Suppose that measurements are available (as they normally are in a VM or OS/390 environment) for the rate of requests r and the miss ratio m Let z represent the...

Ngày tải lên: 03/07/2014, 08:20

... planning Let us, therefore, consider the impact of the average residency time on the performance experienced by a wide range of cached data Figures 1.4 through 1.10 present the performance of a “plain ... substitutions to express the miss ratio as a function of cache size Just as the miss ratio, as a function of the single-reference residency time, takes the form of a simple power law, so does the miss ratio, ... any desired part of the chain through substitution Also, all of these relationships are easily reversed For example, if we wish to express the cache size requirements in terms of the single-reference...

Ngày tải lên: 03/07/2014, 08:20

... demotion of sequential data residing in the cache; the memory for such data is typically freed long before the data would have progressed from the top to the bottom of the LRU list Storage controls ... stage the contents of a standard track image, from the requested record to the end of the track) Then using the typical configuration just suggested, (1.20) calls for a cache size of 0.04 x 0.7 x ... limiting the Hierarchical Reuse Model 23 use of cache memory to identified volumes, while “turning off” access to the cache by other volumes Cache sizes increased sharply with the introduction of the...

Ngày tải lên: 03/07/2014, 08:20

... with the same value of τp across the entire storage pool, we should expect to see a sharp transition at the point where the single-reference residency time of the cache assumes this value The ... Nevertheless, the mathematical model (1.4), with suitable calibration of θ and a, can still be used to produce a serviceable approximation of the miss ratios in the lower memory level, awayfrom the ... also apply at all of the levels below Therefore, there is no contradiction in adopting the hierarchical reuse model as a method of approximating data reference at all levels of a traditional memory...

Ngày tải lên: 03/07/2014, 08:20

... distinct workloads 34 THE FRACTAL STRUCTURE OF DATA REFERENCE Notes Assumes a track belonging to the 3380 family of storage devices Assumes a track belonging to the 3390 family of storage devices ... background in place, we then propose, and analyze, a method by which it is possible to match this behavior synthetically Finally, we illustrate the actual behavior of the proposed synthetic requests ... pattern of requests obeys the hierarchical reuse model, consider the expected arrival rate λ(t), to a specific track, after an amount of time t has passed since some given I/O request The behavior of...

Ngày tải lên: 03/07/2014, 08:20

... identical to the probability of requesting any other leaf of the same subtree, namely 2-Hhi Putting the same fact in a different way, it is the lowest value of 2-H achieved in n trials of the random ... reproduces the asymptotic behavior stated by (2.2) The method of performing the needed random walk can be visualized by thinking of the available tracks as being the leaves of a binary tree, of height ... calculate the random height ≤ H ≤ Hmax at which climbing terminates The next track is then given by the formula where R is a uniformly distributed random number in the range ≤ R < ANALYSIS OF THE SYNTHETIC...

Ngày tải lên: 03/07/2014, 08:20

... projected independently of any other pools served by the cache In the first subsection of the chapter, we examine this hypothesis more closely It leads directly to the needed analysis of cache use by ... calculate the current cache use of each application For example, the current cache use ofthe ERP application is calculated as 04 x 490 x 36 x 197 = 1390 megabytes The total current cache use of the three ... motivate the hypothesis just stated, recall that all workloads sharing a cache share the same, common single-reference residency time τ The effect of the working hypothesis is to proceed as though the...

Ngày tải lên: 03/07/2014, 08:20

... = Then the absolute value of ζi is no greater than 1/.7 = 14 for either workload As a result, the absolute value of either of the second order summation terms of (3.11), calculated without the ... But the summation of these terms, multiplied by the weights rimi/rm, is merely a weighted average; so in the case of the example, the quantityjust stated is the largest relative error, in either ... applications of the working hypothesis: that it makes very little difference in the estimated hit ratio of the cache as a whole, whether the individual workloads within the cache are modeled with their...

Ngày tải lên: 03/07/2014, 08:20

... accumulating, for each hit, the time since the requested data had been at the top of the LRU list The average of such accumulated times yields a practical measurement of g(τ), whose theoretical definition ... 54 THE FRACTAL STRUCTURE OF DATA REFERENCE Use of Memory at the I/O Interface 55 or else by subjecting it to early demotion (this can be done by placing the data at or near the bottom of the ... base the analysis on a trace of the logical data requests made by the application, including those requests served in the processor without having to ask for data from disk A key aim of the case...

Ngày tải lên: 03/07/2014, 08:20

... general form of Figure 4.1 confirms both of the assertions made at the beginning of the section Among the allocation choices available within a fixed 58 THE FRACTAL STRUCTURE OF DATA REFERENCE ... item of data tend to be transient Thus, a sequence of requests to the data may “turn off” at any time; the most recently referenced items are the ones most likely to have remained the target of ... ratio of the storage control and processor portions of the memory budget is This means that 1/(1+0.875) = 54 percent of the total budget is allocated to the processor If, instead, the values of...

Ngày tải lên: 03/07/2014, 08:20