System Diagram Basic structural elements of XdbE architecture XdbE DSC XdbE DSS DS RS DS DS DS RS XdbE DC  shows request direction HTTP HTTP HTTP HTTP HTTP HTTP HTTP HTTP HTTP User Software OCS software or Sider OCS network (data provider) XdbE network (DS network) User software (data requestor)

Basic structural elements of XdbE architecture

System diagram - DS network DSC connects to one selected DS to send OCS data (users, friends, AKA) DS obtains more specific information concerning users (clarifies information) by requesting DSS DS collects all the data in OCS DB DC connects to one selected DS to read the data OCS DB is replicated on all DS servers DS acts as a server i.e. it doesn’t connect to DSC or DC but it responses to requests from them DSC Data add/change Event DS DS RS DS DS RS DS DS DC Data read = = = = = = = = DSS Data clarification request

DSC connects to one selected DS to send OCS data (users, friends, AKA)

DS obtains more specific information concerning users (clarifies information) by requesting DSS

DS collects all the data in OCS DB

DC connects to one selected DS to read the data

OCS DB is replicated on all DS servers

DS acts as a server i.e. it doesn’t connect to DSC or DC but it responses to requests from them