![1211th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
Operational semantics
pred CreateResource [ config : Configuration,
resourceId : String, kind : Kind , t, t ’ : Time ] {
… }
pred RetrieveResource [ config : Configuration,
resourceId : String, t, t ’ : Time ] {
… }
pred UpdateResource [ config : Configuration,
resourceId : String, attribute1, attribute2 : String,
t, t ’ : Time ] {
… }
pred DeleteResource [ config : Configuration,
resourceId : String, t, t ’ : Time ] {
… }](https://image.slidesharecdn.com/cloud2018-4-180706235951/85/Specifying-Semantic-Interoperability-between-Heterogeneous-Cloud-Resources-with-the-fclouds-Formal-Language-CLOUD-2018-12-320.jpg)
![pred CreateResource [ config : Configuration, resourceId : String, kind : Kind , t, t ’ : Time ] {
/ / preconditions at instant t
no resource : config.resources.t |
resource.id = resourceId
kind in config.use.kinds
/ / postconditions at instant t ’
one resource : Resource {
resource.id = resourceId
resource . kind = kind
config.resources. t ’ = config.resources.t + resource }
}
Operational semantics
1311th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA](https://image.slidesharecdn.com/cloud2018-4-180706235951/85/Specifying-Semantic-Interoperability-between-Heterogeneous-Cloud-Resources-with-the-fclouds-Formal-Language-CLOUD-2018-13-320.jpg)
![Catalog of cloud formal specifications
2211th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
IaaS
PaaS
IoT
Transverse cloud concerns
MoDMaCAO [CLOSER 2018]
OMCRI [IoT 2018]
CoT [CoopIS 2017]
Platform [OGF 2016]
Infrastructure [OGF 2016]
CRTP [OGF 2016]
SLA [OGF 2016]
Monitoring [OGF 2016]
Cloud Simulation [EDGE 2017]
Cloud Elasticity [CLOUD 2017]
[OCCIware Deliverable 2.4.1]
[IC2E 2018]
[CLOUD 2016]](https://image.slidesharecdn.com/cloud2018-4-180706235951/85/Specifying-Semantic-Interoperability-between-Heterogeneous-Cloud-Resources-with-the-fclouds-Formal-Language-CLOUD-2018-22-320.jpg)
![Formal transformation rules
& equivalence properties
An instance at GCP is a compute at OCCI
pred ComputeMapInstance [ c : one Compute, i : one Instance ] {
i.name = c.occicomputehostname
i.machinetype.isSharedCpu = c.occicomputeshare
i.machinetype.memoryMb = mul [ 1024, c.occicomputememory ] }
2611th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
Compute
GCP
configuration
OCCI
configuration
resources
resources
String
Integer
Boolean
Instance](https://image.slidesharecdn.com/cloud2018-4-180706235951/85/Specifying-Semantic-Interoperability-between-Heterogeneous-Cloud-Resources-with-the-fclouds-Formal-Language-CLOUD-2018-26-320.jpg)
Specifying Semantic Interoperability between Heterogeneous Cloud Resources with the fclouds Formal Language (CLOUD'2018)
- 1. 11th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Specifying Semantic Interoperability between Heterogeneous Cloud Resources with the fclouds Formal Language Stéphanie Challita, Faiez Zalila, Philippe Merle
- 2. Multi-clouds 211th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Deployment Model Management Interface Service Model Public SOAP IaaS, PaaS, SaaS Public REST IaaS, PaaS, SaaS Hybrid REST IaaS, PaaS Private REST IaaS Aneka Hybrid SOAP PaaS
- 3. Multi-clouds engineering 311th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Programming Libraries Modeling Space Programming Space GCP SDK AWS SDK Provider Space Public PrivateHybrid Cloud provider AWS API Public GCP API Services Cloud architect Cloud developer Modeling languages (TOSCA, CloudML, etc.) OCCI API OCCI SDK … … OS SDK Standards
- 4. Research questions Is it possible to reason on cloud solutions and identify their similarities and differences? - How to better understand cloud solutions? - How to make sure that the cloud solution reflects the desired behaviour? - How to ensure an accurate migration from a cloud solution to another? 411th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 5. Semantic space 511th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Programming Libraries Modeling Space Programming Space GCP SDK AWS SDK Provider Space Public PrivateHybrid Cloud provider AWS API Public GCP API Services Cloud architect Cloud developer OCCI API OCCI SDK … … OS SDK Semantic Space Our approach: fclouds Framework Cloud architect Modeling languages (TOSCA, CloudML, etc.) Standards
- 6. ◊ Fclouds framework ◊ Semantics of the fclouds formal language ◊ Properties of the fclouds formal language ◊ Validation in various cloud domains ◊ Conclusion & Perspectives 611th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 7. Fclouds framework Fclouds1 is a framework for semantic interoperability in multi-clouds ◊ Catalog of precise cloud models ◊ Based on a formal language ◊ Provides formal specifications of cloud APIs - remove ambiguities ◊ Reasons on cloud APIs - verify properties 1. Stéphanie Challita, Fawaz Paraiso, Philippe Merle. "Towards Formal-based Semantic Interoperability in Multi-Clouds: The fclouds Framework." In 10th IEEE International Conference on Cloud Computing (CLOUD). Honolulu, Hawaii, USA, 2017, pp 710 -713. 711th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 8. Fclouds formal language 811th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Formalization of Open Cloud Computing Interface (OCCI) standard in Alloy
- 9. ◊ Fclouds framework ◊ Semantics of the fclouds formal language ◊ Properties of the fclouds formal language ◊ Validation in various cloud domains ◊ Conclusion & Perspectives 911th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 10. Static semantics ◊ Formalization of OCCI core concepts in Alloy ◊ Concepts are modeled as signatures ◊ Time concept is added to distinguish between mutable and immutable fields 1011th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Extension Configuration Resource Link KindAction DataType Attribute Time source target links use kinds types resources action sig Configuration { use : set Extension , resources : set Resource -> Time } 1. R. Nyrén, A. Edmonds, A. Papaspyrou, T. Metsch and B. Paràk, “Open Cloud Computing Interface - Core,” Open Grid Forum, In Specification Document GFD.221, Feb. 2016.
- 11. ◊ Formalization of OCCI behavioral specification1 in Alloy ◊ Operations are modeled as predicates ◊ Time concept is added to distinguish between pre-states and post-states Operational semantics 1111th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA OCCIAPI Create Retrieve Update Delete 1. R. Nyrén, A. Edmonds, T. Metsch and B. Paràk, “Open Cloud Computing Interface - HTTP Protocol,” Open Grid Forum, In Specification Document GFD.223, Feb. 2016.
- 12. 1211th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Operational semantics pred CreateResource [ config : Configuration, resourceId : String, kind : Kind , t, t ’ : Time ] { … } pred RetrieveResource [ config : Configuration, resourceId : String, t, t ’ : Time ] { … } pred UpdateResource [ config : Configuration, resourceId : String, attribute1, attribute2 : String, t, t ’ : Time ] { … } pred DeleteResource [ config : Configuration, resourceId : String, t, t ’ : Time ] { … }
- 13. pred CreateResource [ config : Configuration, resourceId : String, kind : Kind , t, t ’ : Time ] { / / preconditions at instant t no resource : config.resources.t | resource.id = resourceId kind in config.use.kinds / / postconditions at instant t ’ one resource : Resource { resource.id = resourceId resource . kind = kind config.resources. t ’ = config.resources.t + resource } } Operational semantics 1311th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 14. ◊ Fclouds framework ◊ Semantics of the fclouds formal language ◊ Properties of the fclouds formal language ◊ Validation in various cloud domains ◊ Conclusion & Perspectives 1411th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 15. Consistency Definition: “ fclouds language is consistent if it does not contain any contradictory constraints ” ◊ Concepts can be instantiated ◊ Each cloud API operation can be executable 1511th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 16. t1 Sequentiality Definition: “ Two cloud API operations are sequential when one cannot happen if the other one did not happen at the time before ” 1611th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA t2 Update-VM assert CreateResourceThenDeleteResource { ... } t0 No counterexample Cores: 2 Memory: 2 GB Disk: 256 GB Cores: 4 Memory: 2 GB Disk: 256 GB
- 17. Pairs of sequential OCCI operations Sequentiality 1711th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Create Retrieve Update Delete Create Retrieve Update Delete
- 18. t1 Reversibility Definition: “ Two cloud API operations are reversible when they contain inverse mathematical logic ” 1811th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Delete-VM t0 assert CreateResourceReverseDeleteResource { ... } t2 No counterexample
- 19. Reversibility 1911th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Pairs of reversible OCCI operations Create Retrieve Update Delete Create Retrieve Update Delete
- 20. Conformance to HTTP 2 protocol Idempotence Definition: “ A method is idempotent when it always produces the same server external state even if applied several times ” Example PUT Create Resource Safety Definition: “ A method is safe when it does not change the external server state ” Example GET Retrieve Resource 2011th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 21. ◊ Fclouds framework ◊ Semantics of the fclouds formal language ◊ Properties of the fclouds formal language ◊ Validation in various cloud domains ◊ Conclusion & Perspectives 2111th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 22. Catalog of cloud formal specifications 2211th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA IaaS PaaS IoT Transverse cloud concerns MoDMaCAO [CLOSER 2018] OMCRI [IoT 2018] CoT [CoopIS 2017] Platform [OGF 2016] Infrastructure [OGF 2016] CRTP [OGF 2016] SLA [OGF 2016] Monitoring [OGF 2016] Cloud Simulation [EDGE 2017] Cloud Elasticity [CLOUD 2017] [OCCIware Deliverable 2.4.1] [IC2E 2018] [CLOUD 2016]
- 23. Catalog of cloud formal specifications 13 cloud formal specifications 2311th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Extension #Kind #Attribute #Action #DataType IaaS OCCI Infrastructure 5 31 9 20 OCCI CRTP 0 18 0 0 24 251 7 2 Google Cloud Platform 150 2348 985 398 6 19 0 1 PaaS … IoT … Transverse cloud concerns …
- 24. ◊ Verification of fclouds properties via Alloy Analyzer ◊ Definition & validation of domain-specific properties Example In OCCI Infrastructure: Verification of properties 2411th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Compute NetworkNetworkInterface assert NetworkInterfaceBetweenComputeAndNetwork { ... }
- 25. Formal transformation rules & equivalence properties 2511th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 26. Formal transformation rules & equivalence properties An instance at GCP is a compute at OCCI pred ComputeMapInstance [ c : one Compute, i : one Instance ] { i.name = c.occicomputehostname i.machinetype.isSharedCpu = c.occicomputeshare i.machinetype.memoryMb = mul [ 1024, c.occicomputememory ] } 2611th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Compute GCP configuration OCCI configuration resources resources String Integer Boolean Instance
- 27. ◊ Fclouds framework ◊ Semantics of the fclouds formal language ◊ Properties of the fclouds formal language ◊ Validation in various cloud domains ◊ Conclusion & Perspectives 2711th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 28. Conclusion & Perspectives ◊ Fclouds: a semantic solution for multi-clouds interoperability ◊ Reason about the common principles that cloud solutions must adhere to ◊ Fclouds language formalizes OCCI concepts, operations and properties with the Alloy formal specification language ◊ Validation on 13 cloud APIs 2811th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA
- 29. Conclusion & Perspectives ◊ Extend our catalog of cloud formal APIs ◊ Enrich the fclouds language with additional properties ◊ Use formal techniques other than Alloy ◊ Allow the fclouds framework to be executable inside the first formal-based real-world interoperability bridge 2911th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA Active Inactive start start stop Reachability
- 30. stephanie.challita@inria.fr https://github.com/occiware/fclouds-Framework Thank you! 11th IEEE International Conference on Cloud Computing (CLOUD) July 2-7, 2018, San Francisco, California, USA 30