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Towards Globally-Distributed Data

Towards Globally-Distributed Data

1 Global Horizons for Big Data
Big Data is increasingly behind major business decisions [14]. It is now common
for a medium sized company to process terabytes of data a day; and for the result-
ing analytics to support services and management decisions. This trend drives the
analytic database market, which is a major growth area in the multi-billion dollar
database market.
To tackle Big Data we must adopt scalable systems. Parallel databases are lim-
ited in their scalability, since they cope poorly with node failures that are common
on scales of more than a dozen nodes. Thus fault tolerance is key to scalability.
Google was amongst the first organisations that built systems that work with
data on a big scale. Thus the state of the art is heavily inspired by Google’s
technology stack, namely Chubby [5], MapReduce [9], Google File System [10]
and BigTable [7]. These technologies enable data to be processed in a warehouse
scale datacentre, involving tens of thousands of machines persisting petabytes of
data. The academic community is also pushing Big Data further with projects
covering warehouse scale query processing [2, 16] and column stores [15, 1].
Google is now working with data on a still bigger scale. To cope with dis-
asters that damage or disrupt datacentres, Google’s flagship products, such as F1
(Google’s advertising backend), require data to be replicated globally [3, 8]. These
products are required to scale to millions of nodes across hundreds of datacentres.
Global replication brings data closer to consumers, thus improving read perfor-
mance. However, due to fluctuating high latency in a Wide Area Network, global
replication brings significant new challenges. In particular, minute attention to
time is required to maintain adequate consistency.
1
2 The State of the Art
In lectures, we have covered the key technologies that allow Google to process
data on a warehouse scale. Fault tolerant parallel computations are delivered by
MapReduce [9]. Fault tolerant distributed data persistence is provided by the
Google File System (GFS) [10]. Fault tolerant distributed indexing is provided
by BigTable [7]. Many of Google’s services, e.g. Google Personalized Search,
Google Analytics and Google Earth, fit a particular computational model. The
application uses BigTable to lookup data to extract from GFS, which is input into
a MapReduce job. The output of the MapReduce job is then persisted and indexed
using BigTable on top of GFS.
The open source community has developed several projects based on Google’s
scalable systems. Apache Hadoop, the Hadoop File System (HDFS) and HBase
are open source clones of Google’s MapReduce, GFS and BigTable respectively.
Thus anyone can deploy a clone of Google’s systems. For example, Facebook
deploy these Apache Hadoop technologies to manage their multi petabyte data
warehouses [4].
Hadoop, HDFS and HBase all hold data critical for operation and recovery at
a single master node. If the master node were to become unavailable, the whole
system would temporarily become unavailable. Furthermore, catastrophic failure
leading to data loss at the master node could lead to the entire system becoming
unrecoverable. Google achieves a highly available system by removing critical
single points of failure using the Chubby locking service [5]. Chubby removes
the single point of failure, while maintaining consistency, by using the Paxos al-
gorithm [13, 6]. Apache Zookeeper fulfils the role of Chubby in the Hadoop
ecosystem.
3 Towards Globally Distributed Data
It is your job to take our investigation a step further by studying Spanner [8] —
Google’s latest database technology. Spanner is a database that is designed to
meet the data management requirements of Google’s growing suite of applica-
tions. Google’s applications must not only operate at scale, but also must guaran-
tee high availability and prevent data loss. Google achieves these requirements by
replicating data across several datacentres located in distinct geographical regions.
BigTable is designed with the assumption that all nodes are connected on
a high speed network in a single warehouse scale datacentre. Thus BigTable
2
assumes that the round trip between any two nodes is less than a millisecond
(see [7] Section 7). When replicating data between datacentres this assumption
no longer holds. Google’s quick intermediate solution was Megastore [3], which
builds directly on top of several BigTable instances, running in each datacentre.
Megastore is adequate to support several of Google’s flagship products, including
Gmail, Picasa, Calendar, Android Market and Google AppEngine. However, the
performance of Megastore, in particular write throughput, is poor.
MegaStore uses Paxos to replicate primary user data across datacentres on ev-
ery write [3]. Instead of building on top of BigTable, Spanner [8] is a redesign
of Google’s data infrastructure with global distribution at the core. Spanner im-
proves write performance while maintaining strong consistency. The notion of
strong consistency maintained is called external consistency. External consistency
is defined by Gi

ord [11] as follows:
External consistency guarantees that a transaction will always receive
current information. The
actual time
order in which transactions com-
plete defines a unique serial schedule. This serial schedule is called
the external schedule. A system is said to provide
external consis-
tency
if it guarantees that the schedule it will use to process a set of
transactions is equivalent to its external schedule.
Spanner implements a TrueTime API that uses multiple clock references to
keep the global error on actual time within 10 milliseconds. TrueTime is critical
to supporting external consistency, while maintaining good write performance.
Measuring time is known to be important for guaranteeing reasonable progress
for distributed algorithms [12]; however Spanner is one of the few systems where
the finest attention to time is critical. The critical nature of TrueTime in Spanner
gives us new insight into distributed systems as concluded by Corbett et al. [8]:
As a community, we should no longer depend on loosely synchro-
nised clocks and weak time APIs in designing distributed algorithms.
Thus Spanner is a milestone for computer science that demonstrates that time
should be part of the design of globally distributed algorithms.
4 Your Challenge
Your work should be submitted as a technical report written in English. The page
limit is 10 pages. In your report, put yourself in the situation of an systems analyst
3
that is extracting the technical requirements of a scalable globally distributed data
centric system inspired by Google Spanner. You should address the following four
points:
Briefly outline the state of the art for working with Big Data and explain
the role of Paxos in BigTable. Also speculate about how Paxos can be used
to make the master node more reliable in MapReduce. Remember that the
master node holds critical routing and status information about all the nodes
and tasks involved in a MapReduce job. You will require the papers on
BigTable [7], Chubby [5] and MapReduce [9] to answer this question.
Read the paper on Spanner [8]. Use the paper to explain how Spanner uses a
modified Paxos algorithm to replicate primary user data across globally dis-
tributed datacentres. Describe how this modified Paxos algorithm is di

er-
ent from the basic Paxos algorithm [13]. Please use your recently obtained
background knowledge, to expand beyond the explanation of Paxos given
in [8] Section 2. In particular, provide details about how the communication
phases of the modified Paxos algorithm used in Google Spanner work.
Explain what the TrueTime API is and how TrueTime is used to improve the
write performance of Spanner while maintaining external consistency. In
particular, identify how TrueTime is used in the Paxos algorithm described
in the previous bullet point. You should interpret the paper on Spanner so
that developers wishing to implement an (open source) clone of Spanner
can identify the requirements. TrueTime and its usage is covered in Section
3 and Section 4 in [8].
Conclude, by comparing the use of Paxos in Spanner to the use of Paxos in
BigTable. Argue the case for developing an open source clone of Spanner,
by highlighting the benefits of global distribution. Finally, summarise the
technical challenges identified in the body of the report for developing such
a Spanner clone.
The deadline for this report is Tuesday 14th May. Please start reading the
paper on Spanner as soon as possible — it will take several readings to understand.
Also, please contact me before the deadline if you have di
culty understanding
any of the points above.

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a major trade regulation or policy of the United States

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a major trade regulation or policy of the United States

Assess and explain a major trade regulation or policy of the United States. What purpose(s) does the regulation or policy serve? Give a specific example of how the regulation or trade policy might impact developing nations. As always, please provide references to support your efforts.
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Henry David Thoreau

Henry David Thoreau

write a hook to the argument, and use the argument to find a strong argument ( strong thesis statement) to the essay compare and contrast main characters in 4 readings. It means, you should divide into 2 sections. One, compare and contrast Reading 1 and Reading 2 by Jame Baldwin. second, compare and contrast Reading 3 and 4 by Henry David Thoreau
Reading 1: ” My Dungeonn shook” by James Baldwin.
Reading 2: “Note to native son” by James Baldwin.
Reading 3: “Civil Disobedience” by Henry David Thoreau.
Reading 4: “Slavery in Massachusetts” by Henry David Thoreau
Body Paragraph: divide into two paragraphs
First Paragraph, you should compare reading 1 and reading 2 written by James Baldwin characters thinking. the paragraph should conclude 1 topic sentence. a topic sentence contain 4 examples-quotes from the reading. 2 examples for each readings. explain how you choose these examples to support your topic sentence and thesis statement.
second paragraph, you should compare reading 3 and reading 4 written by Henry David Thoreau characters thinking. the paragraph should conclude 1 topic sentence. a topic sentence contain 4 examples-quotes from the reading. 2 examples for each readings. explain how you choose these examples to support your topic sentence and thesis statement.
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CONSUMER CULTURE: GLOBALISATION, MATERIALISM & RESISTANCE

CONSUMER CULTURE: GLOBALISATION, MATERIALISM & RESISTANCE
Discuss the extent to which the globalisation of consumer culture engenders a cosmopolitan culture, where individuals show ‘openness toward a divergent cultural experiences’ (Hannerz 1990: 239). You should discuss your essay using theories of cultural globalisation introduced to you in the lecture and illustrate your arguments with supporting examples.

Key Theories and Suggestions:

• John Tomlinson (2003): Globalisation and Culture
• George Ritzer (2006): The McDonalisation of Society
• Adorno and Horkheimer (1944/2000): The Culture Industry
• Arjun Appadurai (1988): Indigenization
• Hannerz (1990): Cosmopolitanism
• Daniel Miller (1995): Worlds apart: Modernity through the prism of the local
address the question asked and not try to re-define, ‘twist it round’, or state it in more general terms -to allow you to write about something else. In order to remind yourself of this, always put the question addressed at the beginning of your work. ‘Not answering the question’ will result in a significant loss of marks.

• You must demonstrate ability to synthesize key theories and concepts and develop key themes and/or arguments.

• Your essay must be supported by illustrative examples and/or case studies. You are allowed to use supporting media and/or materials (such as images, sound and other medium).

• Being asked to discuss something is not the same as being asked to list statements. A discussion will consider alternative points of view and your own thinking and evaluation should be apparent in the discussion of the topic.

• Your essay must be properly referenced:
o only sources referred to specifically in the text of your answer should be included in the bibliography;
o all sources (including those for any numeric examples used) should be acknowledged;
o there should be no references in your answer to sources which are not in your bibliography BUT if you have not consulted the reference directly yourself you should indicate in the text of your answer the secondary source from which is comes. It is this secondary source that should be in your bibliography.

• Listing a reference in the bibliography does not make it acceptable to copy sections of the book into your answer unless it is explicitly stated as a quotation. You must summarise the points in your own words. Plagiarism is regarded as a most serious instance of academic misconduct and is dealt with accordingly.
• It is expected that you will consult academic and professional journals as well as textbooks. Many textbooks cover much the same information so consulting many different textbooks only results to duplicating this information. Textbooks tend not to have very up to date content and journal sources are vital for this.
• Before you write your essay, work out on paper a detailed outline of your argument.
• In the essay introduction, you should set out your main themes and intentions: describe the issue you are addressing, the illustrative case or contexts you are going to discuss (if any), identify its main components, and indicate what you are going to do in the body of your essay.
• Break down your arguments into main parts – use this as a basis of your essay that will then be divided up into several sections (you may want to have a section title for each section).
• Build up your argument point-by-point, section-by-section, so that you develop a picture that slowly develops in the reader’s mind.
• Always try to put yourself in the position of a critical reader, ask yourself how s/he would react to your essay, how s/he would understand it and be persuaded by it.
• Do not simply describe the ideas and literature you’re dealing with, provide a critical evaluation.
• Summarise your arguments in conclusion. What is the main significance of what you have been saying?
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capitalism and socialism

capitalism and socialism

Compare and Contrast capitalism and socialism and discuss a shortcoming of each system that is criticized by opponents of the system. Then describe the overlap in capitalism and socialism and the economic theory associated with it.

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what are some of the industires in the health care sector?

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Read Chapter 1 (See Chapter 1 link attached below). Provide short answer to the following questions:
1. a. what are some of the industires in the health care sector?
1. b. What is meant by the term health care finance as used in this book?
1. c. What are the two braod areas of healthcare finance?
1. d. why is it necessay to have a book on healthcare finance as opposed to a generic finance book?
2. What is the difference between a business and a pure charity?
3. a. Briefly discuss the role of finance in the health care industry.
3. b. Has this role incresed or decresed in importance in recent years?
4. a. Briefly describe the following health services settinhgs: 1) Hospitals, 2) Ambulatory Care, 3) Home health care, 4) Long-term care, 5) Integrated delivery systems.
4. b. What are the benefits attributed to integrated delivery systems?
5. What role does regulation play in the health services industry?
6. what is the structure of the finance function within health services organizations?
7. What is the primary legal issue facing providers today?

**Please use the link below to access to the first charpter:

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reflection about Journalistic genres

reflection about Journalistic genres

Write a reflection essay about journalistic genres.
Cane toads of the air thrive on stupidity
I’m always amazed by how readily we let our buttons be pushed. It’s almost as though we want them to manipulate us. As though we like it. “Them”, here, obviously includes politicians, advertisers and spin merchants, but the worst offenders, partly because they’re the least explicit, are “shock jocks”.
They are the cane toads of contemporary culture: ugly, ubiquitous, toxic to most other life forms and adept at using their peculiar behaviour to force change in ours.
It’s not so much that they’re rude, lowbrow or just plain wrong, although these, too, are often the case. The most destructive effect of the shock-jockariat is the poisoning of the logic-well itself; followed by the incremental death of the argument tree that is root and branch of intelligent civilisation.
Take Alan Jones. Though it pains me to say it, he is forcing me to change my mind. Not on climate change, or cycling, or the right to public protest, all of which he opposes, but on censorship.

Foucault argued that unreason died with the enlightenment. But the shock-jock phenomenon proves repeatedly that if you make an argument sufficiently idiotic, the sheer scale of stupidity makes it hard to defeat. It was highlighted for me this week by a letter that argued, as Jones does, that anything so small as 0.04 per cent – the proportion of CO2 in the atmosphere – couldn’t possibly matter. “Please let me know,” concluded my correspondent, “how anyone could believe that CO2 is responsible for climate change?”

It’s like arguing that a virus is too small to give you AIDS. Or that a lethal dose of heroin, at about 0.0007 per cent of your body weight, couldn’t possibly kill.
Never mind that applying the same logic to asylum seekers would make you wonder what all the fuss was about (our total asylum applications – 8150 last year, including dependants – being a mere 0.04 per cent of the population.)
These climate-change rants deliberately ignore everything about eco-balance, homeostasis, the greenhouse effect and tipping points we’ve all been taught since primary school and instead raucously promote a red herring.
Yet it’s neither stupidity nor ignorance on Jones’s part. Quite likely he’s read Robert Thouless’s list of dishonest tricks in argument, including caricature, anecdote and non sequitur. Or even Schopenhauer’s list. Bombast, hyperbole, personal insult; certainly he employs most of them.
No, Jones’s position is more cynical. It’s a deliberate appeal to (our) stupidity by (his) intelligence. And it’s not just Jones, or just Sydney, or just climate change.
What’s truly alarming is how accepted it has become that these popular voices deliberately flout the rules of argument. And that, in doing this, they so manipulate the vote that politicians move to appease.
The Adelaide author Ruth Starke has written of her encounter with a South Australian shock jock, Ray Fewings. At issue was a book – Nicki Gemmel’s Cleave. Written for adults, it contained sexuality and was selected by a 12-year-old from the school library. Mother appalled. Controversy ensued.
“Porn!” screamed the jocks. When Starke suggested the mother might have discussed the book with her daughter, Fewings cut her short for “attacking the mother” and accused her of wanting “open slather” so that “12-year-olds could read filth”.
Fewings then twisted this into “What gives Ruth Starke the right to dictate to parents what they should discuss with their children?” and “You heard from a writer who wants open slather to write whatever she wants”. Caricature, insult, emotive language; all core shock-jock stock.
Jones’s infamous carbon tax interview with Julia Gillard in February was scarily similar. First he repeatedly reprimanded the Prime Minister for being 10 minutes late. “I’ve got my job and you’ve got your job . . . 7.10 is 7.10 isn’t it? . . . We’re all busy.” This was followed by dozens of cuttings-in and talkings-over, plus an outright accusation of lying: “There are people now saying your name is not Julia but Ju-liar, and . . . we’ve got a liar running the country.”
Ditto with Clover Moore last May. As the lord mayor arrived Jones was already in a lather, voice raised, epithets at the ready, describing Sydney’s new cycleway as “the virtual destruction” of the city. “Thirty-four thousand votes,” he told her, “you virtually speak for nobody . . . Clover, you haven’t got a clue what you’re talking about . . . For godsake, Clover Moore, can’t you read?”
If all else fails, Schopenhauer recommends clouding the issue through bluff, confusion and induced anger. But beneath the barrage of emotion and insult, the technique here is to make scapegoats of cyclists as the cause of all that angers motorists (when in truth, every bike is a car taken off the road).
Why do politicians tolerate it? Why do we? My theory is this. Most shock jocks, and their audiences, are pretty long in the tooth. Perhaps there’s just a certain kind of person who, as the hormones start to recede, needs this pseudo-emotion to feel alive.
Yet it’s dangerous. We’re used to arguments about civilisation but seldom do we notice just how deeply argument itself underpins civilised life. In the classical tradition, this – rhetoric – was taught in schools. As a basic thinking skill, it came to govern public discussion and debate.
We could do the same. The rules of logic are not difficult. As taught to philosophy sophomores, they cover deductive and inductive reasoning, true and false syllogisms, building arguments with consistency, validity and soundness and – crucially – how to spot a fallacy. Pretty basic.
Without them, however, parliamentary democracy would be impossible. We’d never have risen from the yah-boo of the playground or the might-is-right jungle of silverback tribalism.
You don’t have to look far to see what happens without logic’s civilising structures; it’s the cultural equivalent of those Indonesian abattoirs. Yet this is where shock jocks are coming from and where, if they had their way, they would take us, forcing me to wonder whether censorship mightn’t be reasonable after all.
But there is hope.
Last week, after my cane toads column, several Queenslanders wrote in to say they hadn’t actually seen serious toad numbers for some time. Something, they inferred, is killing them off.
Maybe it’s the same with shock-jockery. We can only hope it happens before it irreparably harms our civilisation, as well as our climate.
Read more: http://www.smh.com.au/opinion/society-and-culture/cane-toads-of-the-air-thrive-on-stupidity-20110608-1fsuj.html#ixzz2TSayERX9

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