Joining the Grid

1
Joining the Grid

• Andrew McNab

2
Outline

• LCG the grid you're joining
• Related projects
• Getting a certificate
• Care of your certificate
• Joining a Virtual Organisation
• AUP

28 March 2006
Andrew McNab Joining the Grid
3
LCG

• The LHC Computing Grid (LCG)
• http//www.cern.ch/LCG/
• The worldwide computing infrastructure for LHC
• Led by CERN
• Majority of resources are at the other sites
• Has more than 100 fully operational sites, in 31
  countries
• About 190 are operational at some level
• Sites from US to Japan, but mostly in Europe

28 March 2006
Andrew McNab Joining the Grid
4
LCG World
28 March 2006
Andrew McNab Joining the Grid
5
LCG Europe
28 March 2006
Andrew McNab Joining the Grid
6
LCG by region
28 March 2006
Andrew McNab Joining the Grid
7
LCG by region
28 March 2006
Andrew McNab Joining the Grid
8
Related projects

• EGEE is also led by CERN
• Develops software to be adopted by LCG
• EU-funded, and intended to get non-HEP on board
• GridPP is the PPARC-funded UK HEP grid project
• Runs LCG in the UK
• Contributes effort to EGEE
• The National Grid Service (NGS) non-HEP UK grid
• Increasingly adopting ideas/software from LCG
• Open Science Grid (OSG) the US DoE/NSF grid
• Increasingly interoperates with LCG

28 March 2006
Andrew McNab Joining the Grid
9
Getting a cert

• All authentication on LCG is done by X.509
  digital certificates
• these contain a unique name for each user
• /CUK/OeScience/OUManchester/LHEP/CNandrew
  mcnab
• To use LCG you need to get a certificate
• This requires proving who you are with photo ID
• For the UK Certification Authority, you start
  this via their website
• https//ca.grid-support.ac.uk/

28 March 2006
Andrew McNab Joining the Grid
10
Requesting the cert
28 March 2006
Andrew McNab Joining the Grid
11
Certificate process

• Apply for the certificate on the CA website
• Choose the right Registration Authority (RA)
• Manchester HEP in our case
• Go to the RA operator (Sabah in our case) and
  provide your photo ID
• You receive an email from the CA when your
  certificate is ready (a day or so the signing
  machine is offline)
• You can then load it into your web browser from
  the CA website

28 March 2006
Andrew McNab Joining the Grid
12
Care of your cert

• Applying for the certificate has created a secret
  Private Key (a huge number) and a Public Key
  (another huge number) which the CA has turned
  into a certificate
• These are inside your web browser at the end of
  the process
• Any body with access to your web browser or the
  Private Key can pretend to be you so treat it
  like a password
• There are instructions on the CA website for
  getting your certificate and private key out the
  browser, and into the file used by the Grid
  command line tools

28 March 2006
Andrew McNab Joining the Grid
13
Virtual Organisations

• Your certificate proves who you are, but doesn't
  give you access to any sites
• To get that, you need to join a Virtual
  Organisation (VO), like ATLAS or BaBar
• Use the User Registration link from
  http//www.cern.ch/LCG/ and follow the
  instructions
• Different VOs have slightly different procedures
• it always involves associating your certificate
  with your request to join
• then a manager of the VO decides if you really
  are a bona fide member of that collaboration

28 March 2006
Andrew McNab Joining the Grid
14
AUP

• Joining a VO requires accepting the LCG
  Acceptable Usage Policy
• This is a common AUP accepted by all LCG sites
• Avoids the need to fax off 190 different Computer
  Centre forms when you join
• The AUP is very short less than a page and
  pretty innocuous
• basically Don't abuse the sites and You're
  legally responsible for what you do.
• In return, you get access to a huge amount of
  CPU, with local accounts created for you on demand

28 March 2006
Andrew McNab Joining the Grid