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

04/20/23 Page 2Semantic Week, Amsterdam

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

04/20/23 Page 3Semantic Week, Amsterdam

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

04/20/23 Page 4Semantic Week, Amsterdam

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

04/20/23 Page 6Semantic Week, Amsterdam

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

What happens in the demo?

04/20/23 Page 11Semantic Week, Amsterdam

With the BREIN solution

• Enhanced Interoperability • Optimal Offer/Counter Offer creation • Support when needed

– Due to the non-invasive annotations

04/20/23 Page 12Semantic Week, Amsterdam