The Basics of Rucio

Last update: 01 Jun 2023 [History] [Edit]

Set up environment

It is strongly recommended if using Rucio to use a fresh / clean shell that is different to the one you are using for Athena etc. If you do need to set up Rucio in the same session, it should be set up at the time you call asetup can be done using:

lsetup 'rucio -w'

To load the environment on lxplus do:

lsetup rucio
voms-proxy-init -voms atlas

and enter your grid password to the voms command, answer yes to any questions (if the client software requests it).

This will set up a proper Python environment to work with Athena, enable the grid environment, set up the Rucio clients and configure them.

tip Note that this will always set up the latest Rucio client version.

Don’t forget to create your ATLAS proxy if you didn’t do this in the first step:

voms-proxy-init -voms atlas

Basic information

First lets ask a few simple questions about Rucio, and what Rucio knows about you.

Use the commands:

rucio ping
rucio whoami

The first command will print the version of rucio that you have set up and the second will print the information about the Rucio account you are using.

tip Note that Rucio accounts can represent users (i.e. you), groups (e.g., Higgs) or activities (e.g., tier0), and your credential (c.f., grid certificate) can map to several of these accounts if required (e.g., for group production roles).

Scopes

Just like namespaces in C++, Rucio has the concept of a Scope and can help to organise datasets etc. To see that there is already a scope for you, type:

rucio list-scopes | grep $USER

tip On lxplus, the environmental variable USER is the same as the nickname associated with the rucio account. On other computers, use the variable RUCIO_ACCOUNT to achieve the same effect.

To see all available scopes, just use the command rucio list-scopes.

All items known to Rucio, e.g., Files, Datasets, Containers, are created within a scope with a name (known as a Data Identifier or a DID), which is unique within the scope. Everything can then be defined with a scope and a name: <scope>:<name>. This is a new feature for those familiar with DQ2.

tip In the MC generation section, you were introduced to the concept of a DSID, which is a number that shows up as a subset of the DID.