1. Event-Based Hybrid Consistency Framework (EBHCF) for Distributed Annotation Records Ahmet Fatih Mustacoglu amustaco@indiana.edu Advisor: Prof. Geoffrey C. Fox

2. Outline Online Collaboration, Tools for Annotation and sharing publications Motivations and research issues Event-Based Hybrid Consistency Framework (EBHCF) Measurements and Analysis Contributions and Future works 2

3. Online Collaboration Rapid development of tools and services Aimed at fostering online collaboration and sharing between users and communities: – Social Bookmarking Tools supports annotation using keywords called tags and sharing e.g. del.icio.us – Tools for annotation and sharing of scholarly publications Connotea Citeulike Bibsonomy – Social Networking Tools(MySpace) – Video Sharing and annotation e.g. YouTube 3

4. Tools for Annotation and Sharing Publications Used for: – Collecting – Annotating – Sharing papers Limitations: – Need to enter same entry to each tool – Different and limited metadata storage – No timing information for updated records – Lack of ability to transfer data between tools – Lack of services to extract and import data into a repository – Lack of services to upload data from a repository 4

5. Metadata Storage in Major Annotation Tools 5

6. Motivations Numerous annotation tools and huge amount of data Generates multiple instances of metadata about the same document No time-stamp info for updated records Causing inconsistencies Different and limited metadata storage Lack of interoperability between annotation sites Applying service-based architecture to annotation systems 6

7. Research Issues I Performance – The benefits and costs of using event-based mechanism and hybrid-consistency framework Scalability – Throughput – The number of integrated annotation tools Flexibility and Extensibility – Interoperable with other clients via SOAP messages – Ease of integrating an annotation tool 7

8. Research Issues II Event-based Model – Major, Minor Events and dataset – Update concept of entities – Efficient and effective event processing Hybrid consistency framework for annotation tools – Conditions and requirements – The way of consistency maintenance Pull+time based and Push based – Advantages and disadvantages 8

9. Event-based Hybrid Consistency Framework (EBHCF) 9

10. Communication Manager Responsible for providing communication between annotation tools and update manager via gateways Utilizes a gateway for each annotation tool, and a parser – Retrieve updates in XML format – Parse and pass updates to update manager – Post updates coming from update manager to annotation tools 10

11. 11 Communication Manager

12. Gateway Interface between hybrid consistency framework and an annotation tool Provides extensibility A gateway needs to be deployed for annotation tool that need to be integrated into the system 12 Gateways EBHCF Modules EBHCF Annotation Tools

13. Event-based Hybrid Consistency Framework (EBHCF) 13

14. Annotation Tools Update Manager Responsible for:  Retrieving the updates from annotation tools periodically  Applying the updates on the primary copy of each record  Propagating the updates back to each annotation tools  Pre-retrieval of existing records 14

15. Event-based Hybrid Consistency Framework (EBHCF) 15

16. Digital Entity Manager Responsible for:  Events and dataset creation  Event Processing Manages updates made on the primary copy of a digital entity  Pass updates to the Communication Manager Handles periodic update management Deals with history and rollback management of a digital entity 16

17. Summary of the Event-Based Hybrid Consistency Framework Event-based model allows – Have all versions of records – Helps ease of changes back to any versions – Once the number of minor events are huge, they can be converted to a major event (compaction) Hybrid Consistency Framework deploys – Pull + time based consistency mechanism – Push based consistency mechanism Pre retrieval expedites the consistency maintenance execution time by decreasing the access time. The updates can be prioritized based on the priority of annotation tools. 17

18. Benchmarks System Performance – Investigation of the maximum number of annotation tools – Improved results for the investigation of the maximum number of annotation tools Scalability – System behavior for the increased minor events – Number of users that can be supported simultaneously Consistency Maintenance – Cost of consistency maintenance for carrying out the updates in primary copy – Cost of consistency maintenance for carrying out the updates from annotation tools 18

19. Benchmark I- Performance I 19 Machine Configurations The goal is to investigate the maximum number of annotation tools that can be supported by the proposed system without performance degradation Every measurement is observed 100 times. We were able to create max of 1400 threads to represent annotation tools We have used: Java 2 Standard Edition compiler with version 1.5.0_12. The maximum heap size of Java Virtual Machine (JVM) to1024MB Apache Tomcat Server with version 5.0.28. Apache Axis technology with version 1.2 Cluster Node gf8.ucs.indiana.edu ProcessorIntel ® Xeon TM CPU (2.40GHz) RAM2 GB total OSGNU/Linux (kernel release 2.4.22)

20. Benchmark I- Performance II 20

21. Benchmark I- Performance III 21

22. Benchmark II- Scalability I The goal is to investigate the scalability of Event-based Hybrid Consistency Framework implementation Measure the round trip time for standard operations like MoreInfo while the number of minor events are increased. Measure the round trip time for standard operations like MoreInfo while the message rate increases. 22

23. Benchmark II- Scalability II 23

24. Benchmark II- Scalability III 24

25. Benchmark III- Consistency Maintenance I The goal is to investigate the cost of our Hybrid Consistency Framework. The cost of consistency maintenance in terms of the time required to carry out updates at the primary-copy holder The cost of consistency maintenance in terms of the time required to carry out updates at the annotation tools 25

26. Benchmark III-Consistency Maintenance II 26

27. Benchmark III-Consistency Maintenance III 27

28. Contributions System research An Event-Based Hybrid Consistency Framework Efficient, scalable, and modular Separation of events as minor and major events Pull+time based and push based consistency maintenance Handling various types of metadata coming from several sources Identifying the circumstances where this architecture has advantages Event-based model Comprehensive benchmarks to evaluate the scalability, performance and consistency maintenance for the prototype system System software A prototype: Internet Documentation and Integration of Metadata (IDIOM) Event-Based Hybrid Consistency Framework for SRG 28

29. Future Works Using EBHCF for the deployment of other online collaboration and sharing tools Improvement of the current event processing engine and the hybrid consistency framework Compaction of increased number of minor events into a major event From a single storage of metadata to distributed storages 29