Developing Collaborative Applications Using Sliverware

Transcription

1 Developing Collaborative Applications Using Sliverware Seth Holloway and Christine Julien COOPIS 06 November 3, 2006 Presented by Seth Holloway The Mobile and Pervasive Computing Group Electrical and Computer Engineering The University of Texas at Austin

2 Outline Problem Motivation Overview of our solution: Sliverware Technical Details of Sliverware Conclusion Questions 2

3 Problem Despite computers widespread use, they still provide a largely single-user experience To overcome this problem, increase the number of multi-user applications Make collaborative applications easier to develop! 3

4 Why is Collaboration Necessary? There are many examples 4

5 Music Composition Music composition can be done collaboratively 5

6 Meetings If everyone has a laptop, why not use them simultaneously? 6

7 Pair Programming The core idea of pair programming is to have two people looking at the same code collaborating 7

8 Conferences Similar to meetings, but (possibly) on a larger scale 8

9 Don t These Applications Already Exist? 9

10 A Few Examples 10

11 A Few Examples How They Work Client/Server Model Single-instance applications 11

12 Future Considerations Diverse hardware and alternative connections 12

13 The State of Collaborative Frameworks Existing frameworks Are hard to understand Are too specific Do not apply to multiple approaches Do not integrate well with other systems 13

14 The Requirements A method to enable collaboration that is Lightweight Easy-to-use Easy-to-understand Applicable to multiple domains 14

15 The Solution Sliverware! 15

16 Contributions Sliverware provides a generic programming framework to add collaboration to any application Sliverware introduces the notion of lightweight, cross-cutting, vertical abstractions Sliverware separates behavioral components of collaborative applications to promote abstraction and reuse 16

17 Traditional Middleware Large horizontal layer that provides functionality for applications Many types: Publish/subscribe Object Request Broker Transaction processing monitors Application servers Applications Middleware Physical Network 17

18 Collaborative Applications Collaborative Functions Collaborative Applications Group Membership Middleware Network Communication Physical Network 18

19 New Applications Middleware Collaborative Applications Collaborative Functions Applications Group Membership Middleware Network Communication Physical Network Physical Network 19

20 Sliverware-Program Interaction Model Collaborative Applications Collaborative Functions Sliverware Group Membership Network Communication Physical Network 20

21 Sliverware: High Level Description Sliverware is a framework that simplifies development of collaborative software Slivers are thin slices of modular middleware that provide a specific functionality Each sliver provides a full application stack 21

22 Sliverware-Program Interaction Model Collaborative Applications Collaborative Functions Sliverware Group Membership Network Communication Physical Network 22

23 Collaborative Services Layer Collaborative Applications Collaborative Functions Sliverware Group Membership Network Communication Physical Network 23

24 Collaborative Services Layer Allows collaborative application developers to focus on high level functions Hides complex, low-level coordination and communication protocols 24

25 Collaborative Services Example Information exchange such as Note placement in a collaborative music application Words in a simultaneous text editor Brush strokes in a group drawing application Screenshots for a remote desktop service 25

26 Collaborative Services Usage A collaborative application = collaborative functions + application-specific behavior 26

27 Group Membership Layer Collaborative Applications Collaborative Functions Sliverware Group Membership Network Communication Physical Network 27

28 Group Membership Layer This component handles all steps necessary to coordinate groups A group membership component developer needs to provide functionality for joining the group This includes any constraints on the group interactions The policy developer must understand the underlying communication interface 28

29 Group Membership Examples Announce Provides open access to the group To join, broadcast a join request for the group To depart, send a depart message Heartbeat Similar to announce, but Requires all participants to periodically broadcast heartbeat messages Inactive nodes are automatically removed from the group 29

30 Groups Defined Groups are defined by a data structure which is maintained independently by each group member The members portion of the group data structure is a list of individual members represented in the form The attributes are largely open ended and will be used for different group policies Example uses of attributes field Time to next expected heartbeat Context information such as location 30

31 Network Communication Layer Collaborative Applications Collaborative Functions Sliverware Group Membership Network Communication Physical Network 31

32 Network Communication Layer No protocol will work for all applications, so Sliverware simply defines a communication interface Allows developers to interchange communication implementations without affecting other components Group membership layer only needs to know the name of a group in which it participates 32

33 Network Communication Methods 33

34 Three Ways to Use Sliverware Developers can create any of the following: Collaborative Applications Adding new application functionality Slivers Creating new combination of Sliverware components Sliverware Components Introducing new low level capabilities 34

35 Programming with Sliverware: Application Developer Application Specific Behavior Collaborative Services Group Membership Policies Collaborative Chosen Sliver Application Network Communication Protocols Available Components 35

36 Programming with Sliverware: Sliver Creation Group Interface Collaborative Services Comm. Interface Group Membership Policies Sliver Network Communication Protocols Available Components 36

37 Programming with Sliverware: Component Creation Collaborative Services Group Membership Policies Network Communication Protocols Available Components 37

38 Programming with Sliverware: Sliverware Optimization Collaborative Services Group Membership Policies Network Communication Protocols 38

39 Programming with Sliverware: Sliverware Optimization Collaborative Services Group Membership Policies Network Communication Protocols 39

40 An Example Sliver: The Distributed Keyboard We present a simple example application, a chat program which displays text in real time This simultaneous chatting is achieved through the distributed keyboard abstraction 40

41 Keyboard Listeners Traditional Keyboard Listener Distributed Keyboard Listener 41

42 Sliverware Chat Application 42

43 Chat Application Stack ChatApplication notify ServiceListener DistributedKeyboard send GroupListener AnnounceGroup Generic Sliverware Interfaces sendall CommListener FloodingComm 43

44 The Take Home Message Sliverware provides a framework to quickly enable collaboration in programs Furnishes a set of lightweight middleware modules spanning the complete application stack 44

45 For more information For more on Sliverware, check For information about our research, please visit 45

46 Thank you!?/! 46