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Many of EGEE's sites are linked together through dedicated network connections. EGEE provides a service that is able to coordinate the bulk transfer of files across the network that allows the connection to be shared between different communities and file transfers to be managed and prioritised.

Computing

Key to nearly all communities supported by EGEE is the ability to analyse file-based data. Generally, applications need to be installed on the compute resources before they can be used to analyse their data. Their availability on a resource is something that can be advertised through the information system and allows the user to select the resources where their applications are already available. These applications are then started through services that encapsulate the compute resource – regardless of the operating system or the internal structure of the compute cluster that will be used to analyse the data.

The user, or their application, uses the EGEE information service to select a compute resource that they have access to and where their application is installed. Any input files needed by the application are transferred from the user’s computer, located in storage out on the EGEE infrastructure through the file catalogue, or by knowing its explicit location, to the compute resource that will be used for the analysis. Once the file is in place, the request to start the application and analyse the file, is passed to the compute service. When the analysis is complete any output files will be available on the compute resource. If the user wishes the output files to remain available for future use they will need to be transferred back to the user’s desktop or stored elsewhere.

Within EGEE some user communities undertake this process manually by knowing where their files are and which compute resources they wish to use. Other communities have written their own applications that directly mimic the manual processes thereby simplifying the life of the user. EGEE provides a generic resource brokering service that is able to automatically perform these tasks for many of the core scenarios previously done manually by a user.

EGEE Architecture
Overview of the architecture of EGEE

Accounting

As the compute, storage and network resources are contributed by different organisations for shared use by groups outside their organisations, it is important that this use is accounted for. Many organisations share their resources through ‘service level agreements’ that specify the proportions of the resource that can be used by different communities. Within EGEE the use of individual computing resources is accounted for and recorded centrally for later analysis and reporting. These usage agreements are validated through these centralised accounting records. Similarly, the volume of data transferred over the dedicated network links between the primary resource centres is also reported. This usage is generally reported for each Virtual Organisation using the infrastructure.

Operations

Vital to EGEE, and for any project that aims to deploy and support an infrastructure, is its operational effectiveness and availability. EGEE's infrastructure is deployed in over 50 counties on over 280 sites and encompasses over 80,000 processors and 20PB of data enough to store 400 million four-drawer filing cabinets full of text or 50 million CDs – a stack around 50km high. This infrastructure is available continuously and supports over 300,000 jobs a day and the research network connecting these sites and the distributed user community sustains transfer speeds of over 900MB/s each day.

A platform for application development

Over the last decade the software interfaces to EGEE have stabilised, matured and now form a platform that provides a basis for external developers to build their own applications. These developers come from both the research community, that use EGEE for their own work, and the broader software community that provide higher-level tools and services for the research community to use. Some of the latter work is starting to appear in the RESPECT programme (Recommended External Software for EGEE CommuniTies - http://technical.eu-egee.org/index.php?id=290) that aims to publicise software and services that work well in concert with the EGEE gLite software and thereby expand the functionality of the grid infrastructure for users, promote the reuse of existing software to reduce duplicated development, and to provide software more oriented to end users than the core gLite middleware distribution.

This activity has expanded over the last year and now includes various software packages:

  • meta-schedulers able to run unattended applications and their related workflows by dynamically selecting resources
  • portals that provide access to EGEE’s resources through a web interface
  • tools that simplify the specification and execution of applications – especially those that involve the execution of the same application over large sets of data
  • services that provide access to data stored in files or in relational databases
  • tools that help developers to build applications to access grid resources

Summary

As the EGEE-III project enters its final year work continues on improving the effectiveness, usability, availability and reliability of the infrastructure. The user community continues to expand and an increasing number of researchers are coming to depend on this e-Infrastructure as part of their regular daily work. In recognition of the increasing maturity of this e-infrastructure, the community has been studying over the last year how this infrastructure can be made more sustainable. The result, the European Grid Infrastructure (EGI), establishes a small organisation that federates and coordinates the work of independent National Grid Infrastructures (NGI) and is due to start in May 2010.

Questions & Answers

can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
im not good at math so would this help me
Rachael Reply
yes
Asali
I'm not good at math so would you help me
Samantha
what is the problem that i will help you to self with?
Asali
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Research in a connected world. OpenStax CNX. Nov 22, 2009 Download for free at http://cnx.org/content/col10677/1.12
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