GOCDB new model for EGEE-III and beyond Gilles Mathieu – STFC GAG meeting, Abingdon 4 December 2008

Current limitations GOCDB3 schema is fine as long as: –we don’t modify it too much –we don’t distribute GOCDB, even partially –regions don’t have specific needs But this will happen… and we may face: –an increased complexity of the relational model –scalability problems –Some regions wanting more, and “leaving the ship” to implement their own solution –interoperability problems

Current limitations These limitations are mainly due to: –The high complexity of the information –The unclear definition of future needs –The low flexibility of relational DB models We must then propose something that: –can cope with any level of complexity –is flexible enough to be easily modified –is customisable to answer regional needs

proposed evolutions Keep a central service, not necessarily a central DB –There is a need for a central access point, but: –the fact that regional DB are distributed or not must not be an issue Build a sustainable architecture that allows regionalisation but doesn’t force it –Not all regions are at the same level Propose an implementation where nothing exists, work with existing solutions otherwise –Some regions have their own solution and don’t want to be forced to use another one

“Imagine no relations, It’s easy if you try…” Proposed DB schema - ID - Sitename - SITES -ID -hostname -IP_addr NODES - ID - path - start_date - end_date DOWNTIMES - ID - name - desc SERVICES - path -SiteID -NodeID -ServiceID PATHS -Type - Name -Database -Grid objectTypes -Type -objectID objects - parent_type -Child_type -Allowed objectLinkTypes -ID -Link_type -Parent_objectID -Child_objectID objectLinks -GridID -ObjectID - Sitename - TABLE1 -GridID -ObjectID - hostname - IP_addr TABLE2 -GridID -ObjectID - serv_name - desc TABLE3 -GridID -ObjectID - start_date - end_date TABLE4 -GridID -ObjectID - Sitename - TABLE1.2 -GridID -ObjectID - hostname - IP_addr TABLE2.2 -GridID -ObjectID - serv_name - desc TABLE3.2 -GridID -ObjectID - start_date - end_date TABLE4.2 -GridID -ObjectID - Sitename - TABLE1.3 -GridID -ObjectID - hostname - IP_addr TABLE2.3 -GridID -ObjectID - serv_name - desc TABLE3.3 -GridID -ObjectID - start_date - end_date TABLE4.3 Current relational modelProposed object model Grid 1Grid 2Grid 3 Core tables (relationships) - Physical Data Tables - Hard coded relationships and constraints Data tables

Proposed architecture Logically separated Grids. We don’t care where they are physically. Central/local access No data duplication Grid n Grid 2 Grid 1 Main core dictionary Local access Central access Core object tables Core GOCDB tables Local GOCDB tables Common schema Custom schema Local Dictionary Shared use Local use A logical grid entity (“regional GOCDB”) The whole system Existing local DB Local entity used directly Use of an adapter if a different local solution exists

Region n Region 1 RAL Custom tables Regionalisation scenario GOCDB Region 1 Region 2 Region … Region n GOC Central portal Region 1 Region n (image) Region 1 local portal Region n local DB Region n local portal Adapter Query interface 3 rd party tools WS interface

Considerations Administration of local systems –responsibility (and maintenance) comes with hosting –GOCDB will: Define the structure of the information to publish Propose an implemented solution Provide tools, APIs, adapters, documentation and support Compatibility with existing tools –No change required once we have moved to WS Hardware/software –Primary implementation of the model on Oracle –Other solutions possible, but that needs investigations

Risks and limitations Multi-server architecture –What if one of the regional DBs is down? –What if some regions change the model? Developers not getting the idea –The model cannot be taken without good understanding

Workplan and timelines By January 09 –Start prototyping new model –2 regional use-cases definitions (NGS and Grid-Ireland) By May 09 –sustainable prototype implementation of the new model –regional use-cases working in parallel with a central DB. –More use-cases study –External adapters prototyped By October 09 –New model operated and in production –More distributed instances, depending on regions choice and/or readiness

For more details… GOCDB regionalisation – New architecture and model description – “A pseudo object database model and its applications on a highly complex distributed architecture” –IARA/IEEE Conference on Advances in Databases (DB 2009) March 1-6, Gosier, Guadeloupe/France