9 th Open Forum on Metadata Registries Harmonization of Terminology, Ontology and Metadata 20th – 22nd March, 2006, Kobe Japan. An Implementation Architecture for ebXML Registry & Repository Federation Day: 20 th Mar. P9 Name: Youngkon Lee Organization: Korea Polytechnic University

9th Open Forum for Metadata Registry, Kobe, Contents  ebXML Registry Features  Registry Federation  Federation Architecture  Federation Metadata  Federated Query  ebRIM  Future Directions

9th Open Forum for Metadata Registry, Kobe, 2006 ebXML Registry Features Content Management Federated Architecture Standard Metadata Events Secure Architecture ebXML Registry Classification, Associations, Taxonomies Cataloging, Validation of Content, Ver- sion Control Federated SQL & XML Queries DSig, Role-Based Access Control, Audit Trail Web Services Registry Publish, Discover, Manage/ Govern Web Services Content-Based Event Notification A Service Oriented Architecture registry as well as a repository Classification of any type of information Managing relationships between information Taxonomy hosting, browsing and validation File/folder organization of information

9th Open Forum for Metadata Registry, Kobe, Registry Federation A registry federation is a group of registries that have voluntarily agreed to form a loosely coupled union. Registry federations appear as a single logical registry to registry clients. Registry Server-1 Organization-A Registry Server-2 Organization-B Registry Client-1 Registry Client-2 Registry Client-1 Registry Server-1 Organization-A Registry Server-2 Organization-B Registry Client-2

9th Open Forum for Metadata Registry, Kobe, Event Notification Event Notification Federation Security Model Security Model Authorization Authentication Access Control Federated Query System Federated Query System Registry A TRP Security Controller Registry Service Object Manager RIM Objects and Security Objects RegRep Object Query Manager Registry B Web Server SOAP Binder Registry Service Controller EJB Application Server Persistence Manager RegRep Security Manager Query Manager Lifecycle Manager Federation Metadata Federation Metadata Replication Relocation Content Management Service Content Management Service Federation: functions to make federation scope and manage life cycle of data object in a federation Federation: functions to make federation scope and manage life cycle of data object in a federation Replication: functions to manage local cache or replica consistently for enhancing performance of federated query Replication: functions to manage local cache or replica consistently for enhancing performance of federated query Relocation: functions for relocating ownership of registry objects Relocation: functions for relocating ownership of registry objects Federated Query: functions required to issue queries targeted to a federation Federated Query: functions required to issue queries targeted to a federation Security Model: functions for guaranteeing safe access and use data securely in a federation: authorization, authentication and access control Security Model: functions for guaranteeing safe access and use data securely in a federation: authorization, authentication and access control Federation Metadata: data structure for managing a federation consistently. It is composed of Federation, Association, Registry Federation Metadata: data structure for managing a federation consistently. It is composed of Federation, Association, Registry Event Notification: functions for notifying change of data objects subscribed in a federation Event Notification: functions for notifying change of data objects subscribed in a federation Federation Architecture

9th Open Forum for Metadata Registry, Kobe, Federation Metadata Composed of Federation, Registry, and Association Should be locally cached and synchronized by polling or event notification AttributeDefault replicationSyncLatencyP1D AttributeDefault catalogingLatencyP1D conformanceProfileRegisty Lite operator replicationSyncLatencyP1D specificationVersion V3.0 RO:registry RO:federation AttributeDefault Time-outP15S SYSTEM-PROPERTIES:registry

9th Open Forum for Metadata Registry, Kobe, Fed. Home Steel RR Rs Trade RR Rt Rh F A Creating Federation Instance R : Registry Instance F :Federation Instance A : Association of HasFederation Member Federation Meta Data A Federation Home can be a Federation Home (FH) by making a Federation Instance

9th Open Forum for Metadata Registry, Kobe, Fed. Home Rh Steel RR Rk Trade RR R F F A’ A Rt A Rk A A R :Registry Instance replica Joining Federation : Registry Instance :Federation Instance : Association of HasFederation Member Federation Meta Data A’ Rt Each registry suggests Association of HasFederationMember and its Registry Instance to FH to be a Federation Member.

9th Open Forum for Metadata Registry, Kobe, Rh Steel RR Rs Trade RR R F F A’ A Rt A Rs A A R A’ Rt F F F : Federation Instance replica Approve joining Federation :Registry Instance replica : Registry Instance :Federation Instance : Association of HasFederation Member Rt A’ Rs A’ Federation Meta Data Rh A’ Fed. Home Rh A’ FH approves joining of candidate registries by sending its Federation Meta Data

9th Open Forum for Metadata Registry, Kobe, Fed. Home Rh Steel RR Rs Trade RR F A’ A Rt Rs A F Leaving Federation Federation Meta Data R F A R F : Federation Instance replica :Registry Instance replica : Registry Instance :Federation Instance : Association of HasFederation Member Rh A’ change F’ In the case of changes in Fed. Meta data, FH should notify it to all of its members to synchronize the replicas of Fed. Meta data.

9th Open Forum for Metadata Registry, Kobe,  FH (Federation Home) Management Problem Any registry can become a FH. One registry may compete against other registry in the same industry or in a country for a FH, so confusion will happen in the middle of each registry trying to become a FH. Solution FH certification authority in each country must manages a certified FHs. Any registry which wants to be an FH should refer an FH list. Federation Meta Data

9th Open Forum for Metadata Registry, Kobe, Registry Client Registry Server-Home V3.0 Registry Server-Remote A1 V2.1 Registry Server-Remote A2 V2.5 Registry Server-Remote B1 V3.0 It is difficult to have Federation if registries have various version of ebRIM and ebRS others (ex)UDDI different version of Registry: failure in query required translation process of ebRIM, ebRS or Backward Compatibility of ebRIM Federated Query  Problem: non-interoperable registries

9th Open Forum for Metadata Registry, Kobe, Determine: local query to local data + replica or remote query Check whether target registries are alive Federated query to registries implemented in various version  Consideration General user Replica and Event Notification Mgmt Remote Query Local Query + Remote Query Result of Remote Query Result of Local Query Federation Mgmt General user Federated Query

9th Open Forum for Metadata Registry, Kobe,  Problem: Performance of Federated Query Search time increases rapidly as the number of Federation member increases, because of limitation of Synchronous method Registry Client Registry Server-Home Registry Server-Remote Registry Server-Remote Registry Server-Remote => Replication of all registry data => Asynchronous Federation Agent Async Federation Agent Federated Query

9th Open Forum for Metadata Registry, Kobe,  Problem: Federated query about local replica If a client submits a federated query to a federation that has many registries with the same local replica, then a client may receive same results redundantly because of same local replica of each registry CO 1 RegRep 3 RegRep 2 Federation RegRep 1 O1O1 1. Fed Query to O 1 O2O2 O3O3 CO 1 Registry Client Replica CO 1 CO 2 CO 3 Replication 3. Response CO 3 CO 2 O 1, CO 1, CO 1 3. Result Reg/Rep O CO Replica Original Data Copy of Original Data O1O1 CO 1 RRR R R R R Retrieve Federated Query

9th Open Forum for Metadata Registry, Kobe, The registry that receives a query must distinguish a federated query from a local query. federated query : the registry must retrieve only its own local data without local replica. local query : the registry can retrieve both local data and local replica. CO 1 RegRep 3 RegRep 2 Federation RegRep 1 O1O1 1. Fed Query to O 1 O2O2 O3O3 CO 1 Registry Client Replica CO 1 CO 2 CO 3 Replication 3. Response CO 3 CO 2 O1O1 4. Result O1O1 RRR Reg/Rep O CO Replica Original Data Copy of Original Data R Retrieve 22 2  Solution: Federated query about local replica Federated Query

9th Open Forum for Metadata Registry, Kobe,  Problem: Latency in Query Response FH Reg Rep Reg Rep Reg Rep Reg Rep down alive 1. Fed query 2. Response 2. No Response A FH is waiting for the response of downed registry Federation 2. Response 3. Low performance When a FH submits a federated query to a downed registry, a FH may wait for a result of a downed registry until time-out. This problem leads to a low performance. Federated Query

9th Open Forum for Metadata Registry, Kobe, Federation Extended Metadata FH Reg Rep Reg Rep Reg Rep Reg Rep down alive 1. Ping Request Message 2. Pong Response Message Federation 2. Pong Response Message 2. Pong Response Message 2. No Response FH Reg Rep Reg Rep Reg Rep Reg Rep down alive 2. Fed query 3. Response Federation 3. Response No Fed query 3. Update Federation Extended Metadata 1. Retrieve A FH submit a ping request message to all members of federation to receive a pong response message from them. A FH excludes the non-response registry in member list temporarily.  Solution: Ping-Pong Protocol Federated Query

9th Open Forum for Metadata Registry, Kobe,  Slot Definition: Object for extending RegistryObject in ebRIM data model. ebRIM (Registry Information Model) Problem: Data Loss According to implementation mechanism (especially RDB-based), it could give an abnormal result in federated query and relocation process. Registry 1Registry 2 C1 C2 C3 C4 C5 RO1 c1 c3c4 c2 c5 Object View RegistryObject Slot Data View C1 C2 C3 SP RO1 c1 c3 c2 RegistryObject Slot C4 C5 relocation

9th Open Forum for Metadata Registry, Kobe,  Classification Definition: Object for RegistryObject taxonomy. ebRIM (Registry Information Model) Problem: mapping Classification Node In the case that there is a difference between the name of classification node, how to match the nodes whose content is semantically same? Registry 1Registry 2 A CB Select Obj from all registries where ClassificationNode = B A CB′B′ FHR Matching B=B ’

9th Open Forum for Metadata Registry, Kobe, Future Directions Focusing SOA architecture Interoperability testing Conformance specification Semantic content management More profiles More protocol bindings (SMTP, RM, ebMS, etc.)