CERN Accelerating science

Using WLCG

How would you like to be part of WLCG?

Individuals and schools

Contribute home computer resources

If you are an individual wishing to contribute your home computer resources, you can become involved in the LHC@home 2.0 project as part of the volunteer computing program.

Student/School wanting to be part of a WLCG project

The WLCG project is concerned with coordinating the efforts of large scientific computing centres and large university departments that have significant investments in computing and networking.

However, schools and students may be able to get involved in some way.

If you wish to work on a project contributing to WLCG, you should contact a local university physics department that has some participation in the LHC physics program and discuss potential projects with them. Have a look at our REBUS Topology to see which institutes are taking part.

If you are based in the USA, there may be a local university that works with the Open Science Grid that can help you.

I want to access the LHC computing grid

To access the LHC computing grid, you must be registered with an LHC-recognised VO (Virtual Organisation). Refer to the dropdown option below under "Site admins and grid users".

Your VO will guide you in accessing the appropriate computing resources.


Users interested in other VOs, please refer to EGI Community Support or Open Science Grid User Support.

Site admins and grid users

Virtual Organisations

The following Virtual Organizations (VO) are supported by WLCG.

VO LHC Affiliation
ALICE ALICE experiment
ATLAS ATLAS experiment
CMS CMS experiment
DTEAM Used by EGI Operations to help set up and debug services at EGI sites
LHCB LHCb experiment
SixTrack Single Particle Tracking Code
MoEDAL MoEDAL experiment

If you are not sure which VO is relevant for you, your work activities will direct you to join the appropriate VO when required.

See also EGI Community Support or Open Science Grid User Support.

Setting up a VO (Europe)

To set up a VO, please go to the EGI Wiki, which explains policies and procedures.

Certificates

To use WLCG you must possess a personal digital certificate from a Certification Authority (CA) recognised by WLCG. The certificate will be needed both during the registration process and also when you submit jobs to the grid.

WLCG accepts certificates issued by CAs who are accredited by the IGTF: Interoperable Global Trust Federation.

Certification Authorities (CA) recognised by WLCG

  • Most people should be able to get a certificate from their national CA. See this list to locate your national CA from the Interoperable Global Trust Federation.
     
  • CERN staff and users (e.g. members of LHC experiments) should be able to obtain a CERN user certificate - see here if you are eligible. If you are, then you can request a certificate.
     
  • If none of the CAs above are able to issue you a certificate:
    • Please consult "Catch-all Certification Authorities for WLCG" in the dropdown below for other possibilities.
    • Please contact project-lcg-certificates at cern dot ch for advice in such cases.

Loading Certificates

Instructions for:

Catch-all Certification Authorities for WLCG

Here we describe options for obtaining certificates if ALL of the following are true:

  • you are eligible to be part of a recognized WLCG Virtual Organisation (VO) (see "Virtual Organisations" entry in list above) or work in a related project
  • you could not reasonably be expected to obtain a certificate from another approved WLCG CA (see "certificates" entry in list above)
  • you require the certificate for an activity related to WLCG or an affiliated project

Procedure

If you do not have a national Certification Authority, and you are not eligible for a certificate from the CERN Grid CA, contact project-lcg-certificates at cern dot ch.

The project-lcg-certificates experts will look into your situation and advise on further action.

There are at least the following potential routes to get user and/or grid service certificates in such cases:

  • If you are part of an organisation affiliated with EGI and related projects (e.g. an LHC experiment), the SEE-GRID catch-all CA service might be able to help you. Mind that it would require a suitable representative for your organisation or country to set up a Registration Authority dealing with the certificate requests. Furthermore, it will cease to exist in its current form when the EOSC-Hub project has ended (Dec 2020). What happens afterwards is still under study.
  • If your NREN (National Research and Education Network) is connected to GEANT, it could subscribe to the TCS service, which typically costs a few k Euro per year and then would provide the NREN with support for user and service certificates needed by the organisations it represents, e.g. universities connected to the NREN infrastructure.
  • For user certificates you may also consider the CILogon service used e.g. by OSG. Mind that an explicit arrangement with CILogon will typically be needed, as their free Basic CA is not included in the IGTF distribution, hence not suitable for use in grid workflows. IGTF currently includes the CILogon Silver CA.

Further links

Historical information

For many years, the WLCG Catch-all CA used to provide certificates for users and services not otherwise covered by one of the approved WLCG Certification Authorities (CA). The service actually was run as a "Registration Authority" (RA) of the OSG PKI. In the spring of 2018 it got decommissioned as part of a reorganisation of the OSG operations services. We thank OSG for having supported the catch-all CA service for many years!

Software

The vast majority of WLCG users are members of LHC experiments or affiliated research projects and should normally use the official software frameworks that are available per experiment or project. 

Each participating site is affiliated with one of the infrastructures that make up WLCG and should normally comply with the corresponding regulations, recommended versions and configurations.

A site normally is expected to provide computing resources via one of the supported Computing Element types and a commensurate amount of storage via one of the supported Storage Element solutions.

Also the network bandwidth (internal and external) needs to be commensurate with the site's resources for the supported collaborations. Additional services are usually needed (e.g. for the information system, authorization or accounting), depending on the infrastructure of which the site is a part.

The exact choice of middleware technologies to be deployed should typically be discussed in advance with the site's (main) customers.

Middleware products

Large-scale resource providers

Register a new site in an existing Federation

Any requests to be part of a WLCG Federation need to be explicitly sanctioned by the Federation Manager. This is because your site's contribution need to be taken into account when calculating the resource commitment per Federation each year.

First, verify that your institute has been covered by a Memorandum of Understanding with WLCG. To do this, contact the Federation Manager of the relevant country - see the Collaboration Board contacts to locate the Federation contact. This person will then be able to advise you which Federation you can be part of.

Next contact LCG Office (either an e-mail from you with the Federation Manager in copy, or an e-mail from the Federation Manager directly) with the following information about the site you wish to register:

  • The Federation you are part of eg. "Brazil, SPRACE, São Paulo"
  • The Accounting Name eg. "BR-SP-SPRACE"
  • The site name according to the GOCDB or OSG - eg. "SPRACE"

We will then arrange to include you in the monitoring tools, accounting and reliability/availability reports.

If your desired federation is not listed in REBUS, then this means your institute/country has not signed a Memorandum of Understanding with WLCG. Please contact the LCG Office to discuss and please also refer to the section Memorandum of Understanding for more details.

Set-up and Register new Site(s) in a new Federation

If you wish to register a new Federation, then your institute/national funding agency will be required to sign a Memorandum of Understanding with WLCG, to set up the framework of agreements regarding resources and services you will provide.

Please see Memorandum of Understanding for more details.