LHC Computing Grid
Encyclopedia
The Worldwide LHC Computing Grid is a computer network
designed by CERN
to handle the massive amounts of data produced by the Large Hadron Collider
(LHC).
It was announced to be ready for data on 3 October 2008.
A popular 2008 press article predicted "the internet could soon be made obsolete" by its technology.
CERN had to publish its own articles trying to clear up the confusion.
It incorporates both private fiber optic cable links and existing high-speed portions of the public Internet
. At the end of 2010, the Grid consisted of some 200,000 processing cores and 150 petabytes of disk space, distributed across 34 countries.
The data stream from the detectors provides approximately 300 GByte
/s of data, which after filtering for "interesting events", results in a "raw data" stream of about 300 MByte
/s. The CERN computer center, considered "Tier 0" of the LHC Computing Grid
, has a dedicated 10 Gbit
/s connection to the counting room.
The project was expected to generate 27 TB
of raw data per day, plus 10 TB of “event summary data”, which represents the output of calculations done by the CPU farm at the CERN data center. This data is sent out from CERN to eleven Tier 1 academic institutions in Europe, Asia, and North America, via dedicated 10 Gbit/s links. This is called the LHC Optical Private Network.
More than 150 Tier 2 institutions are connected to the Tier 1 institutions by general-purpose national research and education network
s.
The data produced by the LHC on all of its distributed computing grid is expected to add up to 10–15 PB
of data each year.In total, the four main detectors at the LHC produced 13 petabytes of data in 2010.
The Tier 1 institutions receive specific subsets of the raw data, for which they serve as a backup repository for CERN. They also perform reprocessing when recalibration is necessary. The primary configuration for the computers used in the grid is based on Scientific Linux
.
Distributed computing
resources for analysis by end-user physicists are provided by the Open Science Grid, Enabling Grids for E-sciencE, and LHC@home
projects.
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
designed by CERN
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
to handle the massive amounts of data produced by the Large Hadron Collider
Large Hadron Collider
The Large Hadron Collider is the world's largest and highest-energy particle accelerator. It is expected to address some of the most fundamental questions of physics, advancing the understanding of the deepest laws of nature....
(LHC).
Description
A design report was published in 2005.It was announced to be ready for data on 3 October 2008.
A popular 2008 press article predicted "the internet could soon be made obsolete" by its technology.
CERN had to publish its own articles trying to clear up the confusion.
It incorporates both private fiber optic cable links and existing high-speed portions of the public Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
. At the end of 2010, the Grid consisted of some 200,000 processing cores and 150 petabytes of disk space, distributed across 34 countries.
The data stream from the detectors provides approximately 300 GByte
Gigabyte
The gigabyte is a multiple of the unit byte for digital information storage. The prefix giga means 109 in the International System of Units , therefore 1 gigabyte is...
/s of data, which after filtering for "interesting events", results in a "raw data" stream of about 300 MByte
Megabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...
/s. The CERN computer center, considered "Tier 0" of the LHC Computing Grid
Grid computing
Grid computing is a term referring to the combination of computer resources from multiple administrative domains to reach a common goal. The grid can be thought of as a distributed system with non-interactive workloads that involve a large number of files...
, has a dedicated 10 Gbit
Gigabit
The gigabit is a multiple of the unit bit for digital information or computer storage. The prefix giga is defined in the International System of Units as a multiplier of 109 , and therefore...
/s connection to the counting room.
The project was expected to generate 27 TB
Terabyte
The terabyte is a multiple of the unit byte for digital information. The prefix tera means 1012 in the International System of Units , and therefore 1 terabyte is , or 1 trillion bytes, or 1000 gigabytes. 1 terabyte in binary prefixes is 0.9095 tebibytes, or 931.32 gibibytes...
of raw data per day, plus 10 TB of “event summary data”, which represents the output of calculations done by the CPU farm at the CERN data center. This data is sent out from CERN to eleven Tier 1 academic institutions in Europe, Asia, and North America, via dedicated 10 Gbit/s links. This is called the LHC Optical Private Network.
More than 150 Tier 2 institutions are connected to the Tier 1 institutions by general-purpose national research and education network
National Research and Education Network
A National Research and Education Network is a specialised internet service provider dedicated to supporting the needs of the research and education communities within a country....
s.
The data produced by the LHC on all of its distributed computing grid is expected to add up to 10–15 PB
Petabyte
A petabyte is a unit of information equal to one quadrillion bytes, or 1000 terabytes. The unit symbol for the petabyte is PB...
of data each year.In total, the four main detectors at the LHC produced 13 petabytes of data in 2010.
The Tier 1 institutions receive specific subsets of the raw data, for which they serve as a backup repository for CERN. They also perform reprocessing when recalibration is necessary. The primary configuration for the computers used in the grid is based on Scientific Linux
Scientific Linux
Scientific Linux is a Linux distribution produced by Fermi National Accelerator Laboratory and the European Organization for Nuclear Research...
.
Distributed computing
Distributed computing
Distributed computing is a field of computer science that studies distributed systems. A distributed system consists of multiple autonomous computers that communicate through a computer network. The computers interact with each other in order to achieve a common goal...
resources for analysis by end-user physicists are provided by the Open Science Grid, Enabling Grids for E-sciencE, and LHC@home
LHC@home
LHC@home is a distributed computing project for particle physics on the Berkeley Open Infrastructure for Network Computing platform. LHC@home consists of two applications: SixTrack, which went live in September 2004, is used to upgrade and maintain the particle accelerator Large Hadron Collider ...
projects.