Semantically enhanced SLA Negotiation
Bastian Koller, High Performance Computing Center Stuttgart
04/20/23 Semantic Week, Amsterdam Page 1
2
Motivation• Contractual relationships between customer and providers require to
support both in the process of service trading• The contract is the result of a negotiation process between both
parties • An SLA can be used as electronic representation of contractual terms• It is important to have a SLA description for SLA templates and the
SLA specification– terms for the provision of the service (service description), – Quality of service (QoS) level to be maintain, – Information about resources to be provided, – the liability to compensation if SLAs are not met.
• WS-Agreement covers the syntactic aspects in the description of SLA, but not the vocabulary terms
• Additionally Current SLA descriptions lack in interoperability:– Open marketplace: Providers and consumers are collaborating on a
global scale competing for offering and consuming services not possible
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Problem Area
Negotiatio
n
Negotiation
Different languages, different metrics
ANSYS request
•CPUName: IntelCore Duo•CPU Speed: 2 GHz•Capacity: 400 MB•Price: 27 euros per day•DiskSpace: 250GB
CUSTOMERSoftware engineering company
-RAMMemory: 7.5 GB-ComputeUnit: 4 ECU-Storage: 850GB-Platform: 64 bit-Price: $0.4 per instance hour
AMAZON
-MemoryPerTask: 7.5 GB-ClockCPUSpeed: 100 MHz / process-StorageCapability: 850GB-Cost: 5 euros/task/hour
BSC
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BREIN (SA)SLAs• Introduction of semantic annotations in current SLA
template files– Based on SA-WSDL– WS-Agreement + WSLA compatible (as based on a
merge of both)
• Allows for annotating SLA description with pointers to semantic concepts
• Annotation of: SLA Parameters. Metrics
Metric Parameter SLO
modelReferences SchemaMappings
Non-semantic descriptions
Semantic descriptions
RDF, OWL, WSML
SA-SLA
SLA template
QoS metrics SLA terms
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A Customer needs something
I need something…I
need this with a duration of 10
minutes
Service Provider
Can you provide?
Customer
I am offering something…with an execution time between 8 and 12
minutesI can with
execution time
But I need with duration
I can with execution time
But I need with duration
I can with execution time
But I need with duration
Welcome to Babel
04/20/23 Page 5Semantic Week, Amsterdam
What we want to achieve
• Customers and Service Provider need to be enabled to understand each other on a common level
• Ontologies can help to overcome this problem• Introduction of Semantic Components, enhancing the
SLA Negotiation Process• Provisioning of a specification for Semantic Annotated
Service Level Agreements – SA-SLAs
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Service Provider Domain
SLA Mediator
duration = ???
SLA Translator
I need something
with duration
I need the ontology for
this customer
Here you areThe SLA Mediator is able to match SA-SLA requests and offers, by converting SLA documents from other domains (e.g. bids or templates) into the local SLA
model to be usable inside the respective domain. It can either query the Translator for the matching Ontology or, in case the Ontology is not available, request this
from a third party Ontology Provider. With the Mediator, the high level SLA Parameters (between
Provider and Customer) can be mapped down to the Service Provider Infrastructure level. The Mediator is
a component in both domains.
The SLA translator is an ontology repository, which allows for managing the local domain
ontology. Within it, the domain rules are formalized. The Translator is a component in
both domains.The Ontology Repository is a third party
storage, where Service Providers as well as Customers can store their Ontologies to make them available for other parties and vice versa,
other parties can query this for ontologies
duration = execution time!!!
Yes we can!!
04/20/23 Page 7Semantic Week, Amsterdam
The Architecture
04/20/23 Page 8
Customer side
Third party
QoS common ontology
Send BidSLA Negotiator
SA-SLASLA Negotiator
Provider side
Local domainknowledge
SLA Template repository
Create Instances
Match request
Do SPARQL query
SLA Mediator
TSLASelector
TSLA Parser
Ontology Manager
Send Offer
SA-SLA
Templates
scores
Semantic Week, Amsterdam
Demo
ANSYS request
•CPUName: IntelCore Duo•CPU Speed: 2 GHz•Capacity: 400 MB•Price: 27 euros per day•DiskSpace: 250GB
-RAMMemory: 7.5 GB-ComputeUnit: 4 ECU-Storage: 850GB-Platform: 64 bit-Price: $0.4 per instance hour
04/20/23 Page 9Semantic Week, Amsterdam
BREIN approach
SLA file semantic annotated
Capacity -> qos:RAMMemory
CPUSpeed -> qos:CPUSpeed
DiskSpace -> qos:StorageCapacity
ANSYS request
•CPUName: IntelCore Duo•CPU Speed: 2 GHz•Capacity: 400 MB•Price: 27 euros per day•DiskSpace: 250GB
•RAMMemory: 1.7GB•ComputeUnit: 1 ECU•Storage: 160GB•Platform: 32 bit•I/O Performance = moderate•Price: $0.10 per instance hour
•RAMMemory: 7.5 GB•ComputeUnit: 4 ECU•Storage: 850GB•Platform: 64 bit•Price: $0.4 per instance hour
•RAMMemory: 15 GB•ComputeUnit: 8 ECU•Storage: 1690GB•Platform: 64 bit•Price: $0.8 per instance hour
SLA file semantic annotated•RAMMemory -> qos:RAMMemory•ECU -> qos:EC2_ComputeUnit•Storage -> qos:StorageCapacity
04/20/23 Page 10Semantic Week, Amsterdam
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