Methodology

The workflow to retrieve the list of users consists of the following steps:

1. The VO managers use the Operations Portal to record VO information in the VO ID cards
2. The information related to VOMS servers is registered in the Operations Portal VO database and made available to the Lavoisier Web Service
3. Lavoisier builds the VOMS contact URL list from the data
4. Lavoisier contacts the VOMSes via a SOAP method and retrieves the list of registered users certificate DNs for each VO
5. The users list is recorded in the CIC database and a cache is also kept in Lavoisier
6. The records are aggregated and sorted to expose consistent VO user statistics on the Web Interface.

If the VOMS server is not reachable the Web Service is not able to retrieve the list of users .

---

User accounting

- we count the number of unique CN and VO group by disciplines or sub-disciplines
- consequently a user represented by a CN could be reported several times
- consequently a VO could be reported several times in different disciplines
- consequently the sum of the users group by disciplines is not corresponding to the total of users

Nb Vo	Number of VOs in this specific discipline and sub-disciplines
Nb Users	Number of users in the discipline and related sub-disciplines

---