DBaaS-Expert: A Recommender for the Selection of the Right Cloud Database

presented by

Alfredo Cuzzocrea

21st Intl. Symposium on Methodologies for Intelligent Systems

Roskilde, Denmark

Soror Sahri*, Rim Moussa‡, Darrel D.E. Long†, Salima Benbernou*

* {soror.sahri,salima.benbernou}@parisdescartes.fr, Univ. Paris Descartes, France‡ rim.moussa@esti.rnu.tn, LaTICE Univ. of Carthage, Tunisia† darrel@cs.ucsc.edu, Storage Systems Research Center, Univ. of California , USA

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ContextDBaaS Providers

(non exhautive list of providers ) Cloud Rationale

Which DBaaS to choose?

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●DBaaS ? »An on-demand, secure, and scalable self-service database platform that

automates provisioning and administration of databases (Forrester 2012)»DBaaS Examples: Amazon Relational Database Service (Amazon RDS),

Microsoft SQL Azure, Heroku PostgreSQL as a service, Amazon Dynamo DB, Google BigQuery, ...

●Why DBaaS ?

»Might be a suitable solution for companies for which in-house database solutions are cost-prohibitive »Cost relates to technology licenses' purchase, administration

expertise, hardware purchase, hardware maintenance, ...

» Cloud advantages:»Cost management: all services are provided on a pay-per-use basis,» Improved quality of service (assuming that providers hire experts)»Resources elasticity: auto-provisioning for scalability through fast new

nodes' deployment and fast release of non-needed nodes

DBaaS

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DBaaS adoption

Source: Next-Generation Operational Databases: 2012-2016 https://451research.com/report­long?icid=2852

Conducted by 451Research, 2013

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●Motivation:» Increasing number of DBaaSs offerings with different services and cost

plans,» It's hard to compare offers, »through check of an advertisement-oriented documentation »through a common benchmark, Indeed, offers target different data

management requirements (OLAP, OLTP, document-oriented, ...)●DBaaSs' offerings ranking problem is a typical Muti-Criteria Decision

Making (MCDM) problem. Indeed, given

»M DBaaS offerings: DBaaS1, DBaaS

2, ..., DBaaS

M

»e.g.: Amazon RDS, Google BigQuery, ...

»N Decision criteria: C1, C

2, ...,C

N

»e.g.: Performance, High-availability, Security, Elasticity, ... »Our goal is to assess DBaaSs' offerings in terms of the set of criteria with

two objectives:»Maximize Quality and Capacity of Service»Minimize Cost

Problem Statement

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DBaaS-Expert Framework

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DBaaS Ontology

The concepts of DBaaS ontology are divided into four categories:● Basic concepts:Basic concepts: DBaaS offer, Cloud Service Provider, Workload Type, Storage Model, Data

Model, Consistency Model, System Constraints, Resource, Trial Version ● Quality of service concepts:Quality of service concepts: SLA, Client Support● Capacity of service concepts:Capacity of service concepts: High Availability, Security, Elasticity, Scalability,

Interoperability ● Cost of service concepts:Cost of service concepts: Cost Model

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DBaaS Ontology

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DBaaS Ontology

Windows Azure SQL Database ontologyWindows Azure SQL Database ontology

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AHP for DBaaS Ranking

●Analytic Hierarchy Process (AHP):»Developed by Thomas L. Saaty in 1970,»Structured technique for complex decisions making, based on

mathematics and user-preferences,»Well-known and extensively used in problems of priority setting,

university faculty members selection (university of Pennsylvania), quality of software systems quantification (MicroSoft).

●The outline of the solution of using AHP for DBaaS ranking is summarized below, »Devise the AHP Tree

● Decision goal at the root of the AHP Tree● Hierarchy of criteria at internal nodes● Alternatives (DBaaS offerings) at leafs»Compute Criteria Weights according to user preferences»For each criterion, assess DBaaS offers »Compute the score of each DBaaS offer

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AHP for DBaaSs' Ranking---AHP Tree

Decision Goal

Hierarchy of Criteria

Criterion

DBaaS Offers

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»Using Pairwise Comparisons for criteria belonging to same hierarchy and same

level. The global weight of a criterion is the product of the weights of its parent-criteria. » The process includes the check of the consistency of weights, and obliges the

user to update initial weights in case of inconsistency. ●Example:

AHP for DBaaSs' Ranking---Criteria Weighting

Resulting Weights

Initial Matrix

All criteria belong to the same hierarchy, The user considers that,● Criterion Ci is half important than Cj (inversely Cj is twice more important than Ci),● Criterion Ci is 3 times more important than Ck,

Cj is the most important Criterion (55.8%) followed

by Ci (32%) then Ck (12.2%)

Iterative Eigenvector calculus through successive matrix squaring and normalizationStop when is negligible which denotes that eigenvector is the same than last iteration

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» For each criterion, an assessment matrix is proposed for comparing DBaaSs. It

is also based on pairwise comparisons.

» The Decision matrix allows the calculus of the score of each DBaaS.

AHP for DBaaSs' Ranking---Scoring DBaaSs

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Related Work

●Comparison through Benchmarking:»OLTP-bench for the cloud: by Curino et al., proposal of new

requirements and metrics for running an OLTP workload in the cloud, 2012 »Numerous benchmarks exist for different needs: Terasoft for sort of 1TB,

...●Comparison using Recommenders, »CloudRecommender for infrastructure services (IaaS) selection: by Zhang

et al. 2012»Cloud Genius framework, also for IaaS services selection: by Menzel et

al. 2012 »SMI Cloud: for measuring quality of Cloud Service Providers based on

QoS attributes, by Gark et al. 2011»Different Services selection from multiple cloud providers: by Quinton et

al. 2013

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Conclusion & Future Work

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● Contributions:Contributions: proposing DBaaS-Expert framework, which allows a user to choose the most suitable DBaaS.● a DBaaS ontology that aims at description of DBaaS offerings.● application of AHP to DBaaSs' scoring in terms of a hierarchy of criteria.

● Future work:Future work: ● Evaluation of DBaaS-Expert● take into account experiences and feedbacks in the ranking of DBaaS

offerings.

Thank you for Your Attention

Q & A

DBaaS-Expert: A Recommender for the Selection of the Right Cloud Database

ISMIS'2014@Roskilde26th June, 2014