TuSoW: Tuple Spaces for Edge Computing

1. TuSoW: Tuple Spaces for Edge Computing Giovanni Ciatto1 Lorenzo Rizzato1 Andrea Omicini1 Stefano Mariani2 giovanni.ciatto@unibo.it lorenzo.rizzato@studio.unibo.it andrea.omicini@unibo.it stefano.mariani@unimore.it 1Dipartimento di Informatica – Scienza e Ingegneria—Universit`a di Bologna 2Dipartimento di Scienze e Metodi dell’Ingegneria, Universit`a di Modena e Reggio Emilia 1st International Workshop on Edge of Things (EoT) Valencia, Spain – August 1, 2019 Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 1 / 26

2. Outline 1 Context & Motivations 2 (Tuple-based) Coordination 3 Our proposal for TbC: the TuSoW project 4 Conclusions and Future Work Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 2 / 26

3. Context & Motivations Next in Line. . . 1 Context & Motivations 2 (Tuple-based) Coordination 3 Our proposal for TbC: the TuSoW project 4 Conclusions and Future Work Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 3 / 26

4. Context & Motivations Our perspective In a nutshell EoT = IoT − Cloud Computation is delegated to edge devices, when possible In Cloud-based applications the Cloud acts as a central coordinator for devices, data, and activities The coordination problem ! How can edge devices coordinate themselves without the cloud? ! And what is coordination in the ﬁrst place? Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 4 / 26

7. (Tuple-based) Coordination Next in Line. . . 1 Context & Motivations 2 (Tuple-based) Coordination 3 Our proposal for TbC: the TuSoW project 4 Conclusions and Future Work Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 5 / 26

8. (Tuple-based) Coordination What is Coordination? Within MAS “A framework in which the interaction of active and independent entities called agents can be expressed” [Ciancarini, 1996] active entities like, for instance, EoT devices and clients interaction i.e., dependencies among computational activities e.g. communication, cooperation, competition, etc. expressed i.e., explicitly represented, observed & possibly governed Takeaway Coordination studies interaction at the fundamental level Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 6 / 26

9. (Tuple-based) Coordination Coordination-as-a-Service [Viroli and Omicini, 2006] as the reference meta-model Coordinated Space Interaction Space Coordination Space Coordinated Entities Requests / Responses Coordination Media A number of entities e.g. edge devices coordinate by means of a number of media e.g. other edge devices, cloud providers, etc wherewith requests and response messages are exchanged e.g. HTTP, MQTT, etc Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 7 / 26

10. (Tuple-based) Coordination Linda [Gelernter, 1985] as the reference model I 1 In Linda coordination media are called tuple spaces 2 They are essentially shared blackboards Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 8 / 26

11. (Tuple-based) Coordination Linda [Gelernter, 1985] as the reference model II 3 where clients can write any sort of information—a.k.a. tuples according to some representation format of choice to: Bob, msg: Hello w rite Alice to: Bob, msg: Hello 4 enabling a feature called generative communication Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 9 / 26

12. (Tuple-based) Coordination Linda [Gelernter, 1985] as the reference model III 5 where clients can read all information matching a particular template according to some query language of choice to: Bob, msg: Hello Alice Bob read to: Bob, msg: * 6 enabling a feature called associative access Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 10 / 26

13. (Tuple-based) Coordination Linda [Gelernter, 1985] as the reference model IV 7 or take it, making it unavailable for other clients Alice Carl take to: Carl, msg: Hello to: Carl, msg: * Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 11 / 26

14. (Tuple-based) Coordination Linda [Gelernter, 1985] as the reference model V 8 or take it, making it unavailable for other clients Alice Carl to: Carl, msg: Hello Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 12 / 26

15. (Tuple-based) Coordination Linda [Gelernter, 1985] as the reference model VI What makes Linda diﬀerent from databases? Suspensive semantics: read and take operations are suspended if no tuple is available Non-determinism: if several tuples are available, read and take operations choose one, non-deterministically Reference uncoupling: devices do not need to know (about) each others ! Such features enable the development of open application where loosely-coupled clients must interact such as in the EoT Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 13 / 26

16. (Tuple-based) Coordination The problem with Tuple-based Coordination (TbC) As further discussed in [Ciatto et al., 2018] TbC is a very well studied research topic for which several proof of concept implementations have been provided coming with as many tuple & template languages ! mostly monolithic, discontinued or inadequate for real world needs Our claim Technological limitations are what actually hinders wide adoption of TbC Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 14 / 26

17. Our proposal for TbC: the TuSoW project Next in Line. . . 1 Context & Motivations 2 (Tuple-based) Coordination 3 Our proposal for TbC: the TuSoW project 4 Conclusions and Future Work Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 15 / 26

18. Our proposal for TbC: the TuSoW project The TuSoW project https://gitlab.com/pika-lab/tuples/coordination Our proposal TuSoW is our Linda-based technology focussing on interoperability lightweightness Avoid repeating past errors Do not commit to any particular runtime platform (JVM, Python, JS, .NET, etc) transport protocol (HTTP, MQTT, gRPC) tuple/template language or matching mechanism since EoT devices may be leverage on any of them Design rationale Design once, port everywhere (with minimal eﬀort) Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 16 / 26

21. Our proposal for TbC: the TuSoW project TuSoW – Layered Perspective TuSoW Core API TuSoW Local Implementation Transport Layer TuSoW Core API TuSoW Remote Implementation iOS Docker JVM Library Linking (De)Serialization HTTP MQTT gRPC YAML XML JSON JS Python JVM .NET iOS Native { { LocalRemote Figure: Dashed lines as choice points Remote impl., supporting mainstream platforms General, abstract, shared core API Presentation layer supporting various data representation formats Transport layer supporting various protocols and diﬀerent applications Local impl., supporting mobile devices and containerisation Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 17 / 26

22. Our proposal for TbC: the TuSoW project About transport protocols HTTP targets web-based & general purpose applications focus on compatibility gRPC targets mobile devices and smartphones focus on portability MQTT targets resource constrained devices (e.g. Raspberries) focus on lightweightness Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 18 / 26

23. Our proposal for TbC: the TuSoW project TuSoW – Spaces, Tuples, and Templates core Tuple Template TupleSpace Match domstringslogic TuSoW HTTP gRPC MQTT implementimplementimplement wrapwrapwrap Client Client_API implements uses Spaces Tuples Templates textual strings regex logic logic terms non-ground terms objects YAML/JSON JsonPath DOM XML XPath Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 19 / 26

24. Our proposal for TbC: the TuSoW project About Tuple Spaces and Tuple/Template languages Textual spaces target coordination of heterogeneous devices handling poorly structured data Logic spaces target coordination intelligent agents prone to symbolic knowledge processing Object or DOM spaces target coordination in the Web of Things Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 20 / 26

25. Our proposal for TbC: the TuSoW project TuSoW – Multi-platform concurrency Diﬀerent platforms come with diﬀerent concurrency model e.g. co-routines on Python & .NET e.g. Futures or Promises on Java or JavaScript e.g. callbacks on Node → Remote libraries must support the most natural style for each platform Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 21 / 26

26. Conclusions and Future Work Next in Line. . . 1 Context & Motivations 2 (Tuple-based) Coordination 3 Our proposal for TbC: the TuSoW project 4 Conclusions and Future Work Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 22 / 26

27. Conclusions and Future Work Conclusion & Future Works Summing up, in this work we argue Coordination-as-a-Service has a role to play in EoT present TuSoW as an interoperable technology implementing it and overcoming current technological limitations In the future we plan to extend TuSoW with access control extend TuSoW with replications, for fault tolerance provide more high-level API, e.g. for FIPA IP [O’Brien and Nicol, 1998] Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 23 / 26

28. Conclusions and Future Work Conclusion & Future Works Summing up, in this work we argue Coordination-as-a-Service has a role to play in EoT present TuSoW as an interoperable technology implementing it and overcoming current technological limitations In the future we plan to extend TuSoW with access control extend TuSoW with replications, for fault tolerance provide more high-level API, e.g. for FIPA IP [O’Brien and Nicol, 1998] Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 23 / 26

29. TuSoW: Tuple Spaces for Edge Computing Giovanni Ciatto1 Lorenzo Rizzato1 Andrea Omicini1 Stefano Mariani2 giovanni.ciatto@unibo.it lorenzo.rizzato@studio.unibo.it andrea.omicini@unibo.it stefano.mariani@unimore.it 1Dipartimento di Informatica – Scienza e Ingegneria—Universit`a di Bologna 2Dipartimento di Scienze e Metodi dell’Ingegneria, Universit`a di Modena e Reggio Emilia 1st International Workshop on Edge of Things (EoT) Valencia, Spain – August 1, 2019 Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 24 / 26

30. References References I Ciancarini, P. (1996). Coordination models and languages as software integrators. ACM Computing Surveys, 28(2):300–302. Ciatto, G., Mariani, S., Omicini, A., Zambonelli, F., and Louvel, M. (2018). Twenty years of coordination technologies: State-of-the-art and perspectives. In Di Marzo Serugendo, G. and Loreti, M., editors, Coordination Models and Languages, volume 10852 of Lecture Notes in Computer Science, pages 51–80. Springer. 20th IFIP WG 6.1 International Conference, COORDINATION 2018, Held as Part of the 13th International Federated Conference on Distributed Computing Techniques, DisCoTec 2018, Madrid, Spain, June 18-21, 2018. Proceedings. Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 25 / 26

31. References References II Gelernter, D. (1985). Generative communication in Linda. ACM Transactions on Programming Languages and Systems, 7(1):80–112. O’Brien, P. D. and Nicol, R. C. (1998). Fipa — towards a standard for software agents. BT Technology Journal, 16(3):51–59. Viroli, M. and Omicini, A. (2006). Coordination as a service. Fundamenta Informaticae, 73(4):507–534. Ciatto et al. (UniBo, UniMoRe) Tuple Spaces for Edge Computing EoT 2019, Aug 1 26 / 26