UCBL and INSA of Lyon

Transcription

1 Project acronym: Project name: Project code: NEBULA A novel vocational training programme on cloud computing skills LLP GR-LEONARDO-LMP Document Information Document ID name: Nebula_WP4_D4.3.1_Learning_Material_and_Content_2015_30_04 Document title: Nebula VET program learning material and content Type: Slides Date of Delivery: 30/04/2015 Work package: WP4 Activity D Dissemination level: Public Document History Versions Date Changes Type of change Delivered by Version /04/2015 Initial Document - UCBL and INSA of Lyon Version /06/2015 Edition Modifications according to feedback provided by partners UCBL and INSA of Lyon Version /09/2015 Edition Insertion of license type UCBL and INSA of Lyon Acknowledgement The persons of UCBL in charge of producing the course are Parisa Ghodous, Catarina Ferreira Da Silva, Jean Patrick Gelas and Mahmoud Barhamgi. The persons from UCBL involved in preparing, translation and review are Hind Benfenatki, Gavin Kemp and Olivier Georgeon. The persons of INSA of Lyon in charge of producing the course are Frédérique Biennier, Nabila Benharkat. The persons from INSA of Lyon involved in preparing, translation and review are Francis Ouedraogo and Youakim Badr. Disclaimer The information in this document is subject to change without notice. All rights reserved. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. This publication reflects the views only of the author, and the Commission cannot be held responsible for

2 Module 2 objectives The aim of this module is to provide the student with the capabilities to understand the cloud business models and the economic impact of these models Note: due to intellectual property reasons, the logotype of UCBL must remain in all utilisation of this course content, as well as the note copyright DUNOD mentioned in some slides with figures.

3 ECONOMIC MODEL IMPACT AND CLOUD MANAGEMENT PART 3: Integration of contractual relationships

4 According to you, what should be a SLA? Is Quality of Service different from Quality of Experience? What is a service level agreement? How can you check if the SLA is respected or not? How will a SLA impact the Business Model?

5 According to you, how can you characterise a Cloud service? In this part you will Learn what QoS and QoE are Learn how you can monitor he Quality of service Be introduce to different Key Performance indicators Learn how to define guarantees in SLA Identify the SLA impact on the economic model Apply this knowledge to write a SLA associated to a Cloud Service

6 PART 3 OVERVIEW 1. Quality of Service VS Quality of Experience 2. Formalisation of non functional requirements and duties 3. Impact of service level agreements on the business model

7 1. QUALITY OF SERVICE VS QUALITY OF EXPERIENCE

8 Quality of service Integration of Business needs for a service What it achieves Functional properties How it achieves the task Non functional properties Performance Delay Price Contract between the provider and the consumer Take into account the different services that are necessary

9 SLA and IS Guarantees of service for Information System focus on Infrastructure Network Application-level Services as mail, video conference P art of IS hosting Web services based architecture development Web Service Level Agreement QoS vs QoE (Quality of Service vs Quality of Experience) QoE: global perception Subjective Can be measured after complex decomposition QoS Objective Can be measured

10 QoS management: what for? Allows adjusting the system s capacity To limit costs To choose adapted equipment To allow integrating new requirements New types of flows Increasing data volume Check the provided service Check for a minimum value of the service level Periodic checking Preventive maintenance duties Action on configuration management Anticipation of break-down / failures

11 Performance evaluation (1) 2 complementary aspects Capacity of the system to process the required applications Qualitatively Quantitatively Performance measures Availability Part of the time when the system can be used Safety Security Extensibility Scalability

12 Performance evaluation (2) Measuring performances Depending on the application type Work lot duration System throughput RESPONSE TIME Stability Margin to face increased demand Let ART be the average response time S(X,Y)=(ART of Y% of messages at X% of peak charge)/ ART of Y% of messages at (X+10)% of peak charge S <1 and closest to 0.9 If S 0.6 or 0.7, the system is close to saturation point Time Usage rate

13 Quality of Service or Quality of Experience? Quality of Service Measurable Objective Quality of expérience Subjective Progressive adaptation to performance degradation Giving up Gradual degradation is not perceived Problem The client «feels» the QoE The contract guarantees the QoS

14 Service guarantees Management during the «production» period SLA: Service Level Agreement Historically defined by Telcos Extended for information System Contractual relation by mutual agreement Management of the provided QoS Performance indicators (KPI) Key Quality Indicators (KQI) Control the reached quality level Service Level Management Specific software» Metrology» Management of the different indicators as stated in the contract External provider

15 Checking guarantees: SLA, SLM, KQI, KPI Hierarchical organization (Subjective) definition of quality indicators QoE specification in the SLA KQI are turned into a set of performance indicators Instrumentation Acquisition system Monitoring Performance indicators evaluation (KPI) Indicators consolidation to compute global Quality Indicators (KQI)

16 Monitoring the Quality of Service Take into account the different resources Devices (including phones, mobile devices such as smart phones, tablets ) Application resources Management of enterprise's internal resources Management of external resources Service availability Unavailability rate SUA% = (( S unavailable times periods)/ total time)*100% Service degradation rate (SDF) SUA%= (( S unavailable times periods *SDF)/ total time)*100% Management of the different kinds of failures Billing impact

17 Some Key Indicators (1) Data transfer Delay Jitter Response time, Loopback time (cycle request / response) Goodput Throughput Processes Locking rate Transaction rate Authorisations Confidentiality Integrity Non repudiation Computers / virtual machines Idle times Disk space

18 Some Key Indicators (2) Usage facilities Help desk Training opportunity Interoperability Processing mode Connect time (launching time) Time to close Degraded mode operation Usage Pick-up time: delay to be able to answer Queuing times Required time to set / revoke authorisations Others Quality of speech (applications including voice)

19 Indicators and obligations Integration of tolerance thresholds For each indicator Graduated scale Alert thresholds Error thresholds Allow to react and anticipate Penalties Gradual Depending on alert and error thresholds Error area Alert area Normal area Alert area Error area

20 Implementing metrology Continuous measurement of performances According to the specified indicators Bias due to the intrusive characteristic of the metrology process One-shot tests Different tools Operating System and Network operation Database managed in Round Robin style Different dashboards Alert systems (SMS, mail)

21 2. FORMALISATION OF NON FUNCTIONAL REQUIREMENTS AND DUTIES

22 Guarantees definition (1) QoS First defined by Telcos for networks Average performance measure Average rate of unavailability Instantaneous performance measurement Duration of a transaction Allow resources management and a global improvement Tag depending on the requested QoS Resources management based on these tags Congestions management Involves having adapted management tools

23 Guarantees definition (2) Security Included for each service 3 basic security services to take into account Integrity The service and / or the information must be available and must not be modified by unauthorised actors Confidentiality The service and / or the information must not be acceded or understood by unauthorised actors Non repudiation Guarantee the source identity Involves counter-measures for Sites (Global Secure Environment) Rooms (Local Secure Environment) Access points (devices) : Electronic Security Environment Complementary services (journals ) Applications (audit de code )

24 Guarantees definition (3) Required qualification level To manage resources For end-users To manage the monitoring tools To compute penalties (!) Involves organizing training plans Decommissioning Annex costs management Equipment suppression (routers, probes ) Archives costs Financial compensation in case of anticipated revocation

25 Integration of SLA in Information Systems Layered Information System organization Identification of the different kinds of applications Functional decomposition of the enterprise Frameworks related to the business sector Rationalization of «support services» Access to the infrastructure Interaction between different services Allow analyzing the performance of each one Manage the responsibility limits Contractual relationships End to end contract QoE related to the end to end view SLA between adjacent services

26 Business service according to Telcos Support for different types of application Communication Voice Video-conference (point to point or multicast) Streaming (audio, video or data services) Telemetry (equipment monitoring) Transactions Broadcasting Teleworking (occasional or permanent) Assistance (help desk) Network Intranet Extranet (Public) Internet Security

27 Business service according to the client Depending on the client The one who operates the IT system The one who uses the application Business Service SaaS Level Data integration Different environments Access device May determine also network resources Invocation for different purposes

28 End to end service level management Take into account the different components Different performance indicators Acquisition modes Different measures Measures aggregation Internet Delay measure: ping Application QoE: 10s Infrastructure Network 3s 3s 2s 2s Delay measure: transaction duration Usage typical measures: CPU rate, IO (qte and delay), memory consumption Delay measure: ping

29 Writing a SLA from patterns (1) Method proposed by the Open Group Identify the business area of the enterprise Identify the «Business applications» belonging to this area Associate services and resources to each application Select (from the patterns) the typical KQI associated to each service (you can even use subjective indicators) Identify KPIs and their thresholds for each service depending on the KQI Proceed to the approval of the SLA Implement the monitoring

30 Writing a SLA from patterns (2) Link between SLA and service Joint definition Upstream preparation of the SLA Before the service selection Determine the choice of the provider Determine the offered services Before the service configuration Evaluation of QoS needs Loops are possible Economical decision-making

31 Composition of a SLA In substance: 5 elements to take into account What the provider promises How the provider will deliver what has been promised Who will measure (and how) the real service Take into account the provider s failures Number, duration Penalties How the SLA may evolve Contractual structure Parties identification Contract approval Parties Releases management Service context Forecasted performances

32 Use case Proposed the SLA structure to guarantee a high availability for the web portal associated to the e-service hosted in a Cloud

33 3. IMPACT OF SERVICE LEVEL AGREEMENTS ON THE BUSINESS MODEL

34 Economical optimisation Client viewpoint Cost reduction But a maximum QoE! Provider viewpoint Competitive offer Resources use is maximised Avoid paying penalties Require to balance these viewpoints To avoid error areas Reach profitability for both actors

35 Sizing Needs estimation Average Consumption peaks Depend on the success rate of the offer Saturation points Locking points (memory ) QoS bottlenecks Disks accesses Network Challenges Fast upgrading Optimized management of resources

36 Bias on the QoS reated to response times Essential indicator for users Depend on the system loading rate Performance degradation Progressive Well-accepted: self-adaptation for users Self-regulation due to users giving up 20 High variance 18 Rough break 16 Misunderstanding Less acceptable 10 Low variance 8 6 Deployment duration 4 Low Average High ,05 0,1 0,15 0,2 0,25 0,3 0,35 0,4 0,45 0,5 0,55 0,6 0,65 0,7 0,75 0,8 0,85 0,9 0,95 1

37 Information acquisition Existing analysis Building a time-series model Projection over 5 years 10 Years history! Quantitative information precision Depend on the forecasting horizon For 1 year: accurate within 20% For 2 or 3 years: accurate within 50 % Anticipate evolutions Model built Using incomplete data Pessimistic: who can do more can do less!!! Take care of subscription duration / decommissioning

38 A priori evaluation method: Design step Mathematical modeling Proof of functioning Theoretical calculation Simulation Dynamic operation of a model Identify the simulation context Deterministic inputs Replicate experiments Allow direct comparisons Random inputs Reproducible testing context? Hypothesis tests

39 QoS control Runtime Real use Usage control Similar to forecasts? Standard periods vs peak periods See what s happening Set an efficient performance measurement system Intrusive system! Look at the traffic (Re)act Configuration of equipment Book resources

40 Actions to maintain QoS Intervention for periods of (over)load Anticipate saturation Congestion risk that may lock definitely the system (network or memory saturation ) Useless to launch a transfer / a process if there s a saturated bottleneck Identify locking points Passing areas High traffic concentration points Select who will be penalized Big consumer? Everybody? The one who will have the lower cost?

41 Impact on the business model Integrate risks due to SLA On the client side Estimate over-loads due to monitoring activities Negotiation related to «non functioning times» Define the responsibilities perimeter On the provider side Integration of failure probability Hardware Software (bugs, new use cases ) Success of an offer / saturation Integration of responsibilities perimeters For packaged offers

42 Operation and QoS management (1) Preventive actions QoS monitoring Equipment monitoring Identification of load rates Use aggregation on basic measures to get a global view On the flow measures Planned in the contract Periodic tests» Allow to have a real objective view of the system performance to compare with the QoE Dedicated tools to manage bandwidth Mostly for WANs (Wide Area Networks) Define some quota for key applications Exploitation of trends thanks to dashboards Identification of peak periods Monitoring of predictable wear Tune the configuration Set booking policies Parameters tuning (cache sizing )

43 Operation and QoS management (2) Curative actions According to the assessed urgency Blocking biggest consumers 1 dissatisfied instead of several Management of the different kinds of flows Booking resources Consumption forecasting Real time constraints Tune the capacity of some virtualized equipment CPU Memory size Re-evaluation of the architecture Needs evolution Servers location Cabling layout management Subscription evaluation

44 Perimeter of the system management ISO definition Fault Identify, isolate, correct and log faults / failures Involves a notification Configuration Configuration storage Simplify the configuration Monitor changes Accounting Who uses what Quota management Billing Performance Efficiency evaluation Throughput, error rate, use percentage, response time Security Authentication Encryption Authorization

45 Application Cloud Operation A production job Basically: Activity reporting Monitor and govern to tune the system to face needs Emergencies Answer when the system is down (or seems to be down) Identify where is the problem Along the connection chain» computer (source, target)» Other equipment Applications» Hypervisor or application components Identify why Component out of use Bad configuration Anticipate problems!

46 Organisation of the operation An organization planned to integrate unpredictable events Everything can occur but you don t know when it will occur! Complex system Different skills centers Application Operating System / Hypervisor Networks Different responsibilities limits Definition of operation processes To capitalize experience To industrialize operational day to day processes

47 Interest of services industrialization Rationalize operation tasks Role definition Responsibilities areas Skills Organization of different processes Capitalize on best practices Define operation levels depending on the skills CMMI can be used to evaluate the rationalization level Plan operation Get necessary resources Evaluate the service to provide according to the service level agreements