Service Level Agreement

Summary

In this lecture on cloud computing, the focus is on Service Level Agreements (SLAs), which are vital contracts between service providers and consumers ensuring defined levels of service quality, availability, and performance. The speaker highlights the various components and parameters involved in SLAs, their importance in cloud adoption, and how they are tailored based on consumer requirements such as uptime and data persistence. Additionally, the role of SLAs in maintaining trust, managing performance metrics, and ensuring compliance with auditing and legal standards is emphasized.

Highlights

• Introduction to the importance of SLAs in cloud computing and their role between providers and consumers 🤝.
• Discussion on the different components and measurable objectives within SLAs 📏.
• Real-world examples of how SLAs are customized for different organizations, like financial companies versus academic institutions 🏢.
• Explanation of the auditing and remedial processes involved in SLAs to ensure compliance and trust 🔎.
• Overview of how SLAs are implemented across different cloud services, from IaaS to SaaS ☁️.

Key Takeaways

• SLAs are crucial agreements that define service quality in cloud computing 🌥️.
• Different objectives in SLAs cater to varied consumer needs, like uptime and data persistence 📊.
• SLAs include parameters for service availability, pricing, and performance metrics 🏷️.
• Auditing mechanisms in SLAs ensure the compliance and trust between providers and consumers 🔍.
• SLAs adapt to various cloud services like IaaS, PaaS, and SaaS, each with different requirements ⚙️.

Overview

Service Level Agreements (SLAs) are the backbone of trust in cloud computing, providing a formal contract between service providers and users. These agreements cover essential aspects such as service availability, pricing, and performance to ensure that users receive the quality of service they expect.

SLAs are not one-size-fits-all; they are tailored to meet the specific needs of different consumers. For instance, while an academic institution may prioritize data persistence, a financial company might emphasize 99.9% uptime to avoid any disruptions.

Furthermore, SLAs involve intricate details like auditing mechanisms and remedial processes, ensuring that both service providers and consumers adhere to the agreed terms. These components are critical in maintaining service quality and compliance with legal standards, making SLAs an indispensable part of cloud services.

Chapters

• 00:00 - 00:30: Introduction to Cloud Computing The chapter introduces the topic of cloud computing. It sets the stage for discussing a major aspect of cloud computing without going into specific details.
• 00:30 - 02:10: Service Level Agreement (SLA) Overview The chapter provides an overview of Service Level Agreements (SLA) in the context of cloud computing. It discusses how SLAs are essential when a consumer and a provider (or service consumer and service provider) exchange services that incur costs. The agreement outlines the terms of service involving metered services.
• 02:10 - 05:00: Components of SLA The chapter 'Components of SLA' discusses the various elements that constitute a Service Level Agreement (SLA). It highlights that pricing and service availability are critical components of the SLA. The agreement may also encompass other quality factors, which can be complex issues. The chapter further explores the challenges faced by organizations or individuals when transitioning from their own proprietary computing setups to cloud services provided by external service providers, with an expectation of reliability.
• 05:00 - 10:00: Web Services SLA The chapter "Web Services SLA" discusses the necessity of having service-level agreements (SLA) for ensuring similar levels of reliability, performance, and security in web services as one might have for on-premises systems. It highlights the lack of a standardized format for SLAs, which is a concern when purchasing services, virtual machines (VMs), or other cloud services.
• 10:00 - 15:00: Types of SLA This chapter delves into the types of Service Level Agreements (SLA). It discusses the nature of SLAs as agreements that involve terms and conditions agreed upon by involved parties. The chapter outlines the different parameters that are typically considered in an SLA and describes the typical structure and components of an SLA. Additionally, it gives an overview of the SLAs from popular cloud service providers, highlighting the variety of SLA parameters they offer.
• 15:00 - 20:00: Objectives and Management of SLAs The chapter "Objectives and Management of SLAs" introduces the concept of Service Level Agreements (SLAs) as formal contracts between service providers and consumers. It explains that SLAs are foundational to building consumer trust with providers, especially when purchasing services. The lecture aims to explore the objectives and management strategies essential for effective SLAs.
• 20:00 - 25:00: Additional SLA Considerations The chapter 'Additional SLA Considerations' discusses the importance of having a Service Level Agreement (SLA) to establish a formal basis for trust between a service provider and a customer. It highlights that SLAs can help compare different service providers by their performance and availability guarantees. The primary purpose of an SLA is to provide assurance of service delivery and uptime reliability.
• 25:00 - 30:00: Conclusion In the conclusion, the discussion focuses on the importance of service providers guaranteeing a high level of uptime, specifically targeting more than ninety-five percent to ensure reliability. The conversation elaborates on the concept of service level agreements (SLA), highlighting that they encompass various objectives. These objectives, known as service level objectives (SLOs), are designed to be objectively measurable, ensuring that the service quality is consistently met.

Service Level Agreement Transcription

• 00:00 - 00:30 hello welcome to this ah lecture on cloud computing ah today we will be discussing one one of the important topic ah of ah cloud computing ah or one of the major aspect of
• 00:30 - 01:00 making this cloud computing ah to realize this is the service level agreement right whenever a consumer and a producer or a service provider and a service consumer ah want to exchange any services or what we say meter services which involves some costing there is a there should be some agreement on the things right so ah ah the agreement ah involve
• 01:00 - 01:30 the pricing factor agreement involve the service availability factor the agreement may involve say for as other quality factors now this is very tricky issue and ah because a organization or even individual is switching for his own personal or own ah proprietary computing paradigm to some ah cloud taking the service from some service provider thinking that you will get same type of reliability
• 01:30 - 02:00 and other reliability same type of performance same type of security what he was having in his ah own ah premises right the system said it been in own own control now in order to that he need to have some agreement on the things so as as such there is a still today ah till today they we dont have any very standard format of doing that hm what you usually face whenever we are purchasing any services or any taking any vm or any cloud
• 02:00 - 02:30 provider what we are usually do we basically sign off something right we say that these are the terms and condition we agree so some sort of agreement will be there so we want to see that what are the different parameters to be taken into consideration and how this service level agreement typically look like what are its different components and at the end some of the popular ah cloud service provider what sort of sla or what sort of ah sla parameters
• 02:30 - 03:00 they are ah providing that we will ah we will see in this particular lecture today so ah if we look at what is what is sla or service level agreement a formal contract between the service provider and the service consumer so that is the thing sla is the foundation ah sometimes known as the foundation or sometimes refer the foundation of the consumer trust in the provider right whenever i purchase some service the first thing come as how much
• 03:00 - 03:30 i can trust to the provider so this may gives me a formal ah way of trusting the thing that if the sla is there not only that this may help me this parameters to compare between one provider with the other provider whom to i will take the service so purpose is to define a formal basis for performing and availability of service provider guarantees to the to delivery i need to a guarantee to the delivery if i require a uptime
• 03:30 - 04:00 of say ninety five percent so there should be guarantee of delivery of ninety five percent right so i want those service provider which guarantees that i am i am more than ninety five percent uptime it provides right so sla now if you see sla is is a broad term right so it has to have different objectives right so that what we say service level objectives so what this slos ah does objectively measurable
• 04:00 - 04:30 condition for services right sla is the agreement agreement has different components and this these are objectively measureable i say that performance should be ninety five percent so its its cannot be so somewhere objectively i should measure the thing so this so sla constitute of number of objective basis and these later on we will see these objectives can be calculate from different ah parameters right or system level parameters which which
• 04:30 - 05:00 i can calculate so these are ah these are objectives which are there now interestingly the objective may vary from the consumer to consumer like even a ah consumer if a if a service consumer like a academic institution like us may have different type of ah objective or may have not totally different i say may have different type of focus on the objectives then a consumer like may be a financial organization or a software company
• 05:00 - 05:30 so they have a different type of ah strategy level objective like i can say that my uptime maybe i can have ninety five percent ah however i may require that data persistence to be much higher right some other organization say that my uptime is typically more than ninety nine percent it cannot be compromised less than ninety nine percent however my i always take a backup
• 05:30 - 06:00 of the data so i may not always require a backup facility and objective etcetera right so that can be other things i can have my objectives varies or varying over time i say during peak hours my availability should be more than ninety nine percent whereas during of peak hours my availability requirement of availability may be more than ninety percent right so these things are somewhere objectively measurable thing so this components should come into play so what are the different ah sla typical contents we are looking for so it is a set of services
• 06:00 - 06:30 which provider will delivery so it should specify the set of services the provider will delivery i would like to again reiterate so these are these slas are valid for different type of ah service provisioning may i would like it can be iaas type of ah services where the sla he want to have you can have pas type of services you can have saas type of services or any type of other type of things like may be ah data services etcetera so this slas
• 06:30 - 07:00 correspond to that type of with that respect right so sla for particular which is a software as a service type of module and so and so forth so it should be complete specific definition of ease service right so it is been complete specific definition responsibilities of provider and the consumer to respect these sla ah a set of metric to measure whether the provider is offering the services as guaranteed like how do i know that whether the thing so some metrics should be there that which we shows
• 07:00 - 07:30 that that it is providing the whatever it is guaranteed a auditing mechanisms right interesting a auditing mechanism to monitor the services so i need to have a some auditing mechanism to monitor the services right so it may be a third party auditing like i purchase ah as a service consumer purchased from service provider but a ah a third party auditor basically sees that where that there is a violation of the services etcetera right so these are the things which are to be ah to be monitored
• 07:30 - 08:00 so that is auditing is required the remedy is available to the consumer and the provider these are terms are not satisfied that is another thing is there what should be that some sort of a payback mechanism or what should be the remedies if this is not like if i say if it is if if i require a uptime of ninety five percent and if the provider fails to give me ninety five percent for sometime so whether he should pay me back or provide some other incentive to do that right so that should be some mechanisms where things are valid
• 08:00 - 08:30 right so there should be and ah if you if we see that for a our ah day to day activity organizational activity there are this type of agreements mous etcetera where there are things for defining that objectively there are remedies for violating those things what will happen and so and so forth there are penalty what we say penalty of not providing the guaranteed service if i if i say that
• 08:30 - 09:00 i have give a guaranteed service and it is not provided then what i should pay give some penalty or i need to give some other incentive to do to compensate that that should be also specified right what if there is not guaranteed etcetera and how whether the sla will change over time right it may change over time ah during the particular day of the things it may change over time over different days of the time and etcetera etcetera so there is a whether the sla will change over time that is another so whether it is a temporally changing
• 09:00 - 09:30 phenomena right now there is a concept of web services ah i believe ah most of you are ah having a thing service oriented architecture and web services which are one of the what we say prime over for coming up the of this cloud services for benefit of all i will take one short lecture on later on in subsequent ah togs one web services and service oriented architecture those who are not a custom but i believe that most of you are used to it and type of things
• 09:30 - 10:00 right so there is a in case of web services where service provider and consumer there is a concept of they communicate with each other there is also a agreement thing right or what we say web service sla so web service sla there are component like one is that web service agreement the xml based language and protocol negotiating establishing and managing the service agreement at the run time so its a ah de facto xml based things actually the whole web services things and so on basic
• 10:00 - 10:30 foundation of xml specify specify the nature of agreement template so what should be the agreed upon format of the template of the things facilitates in discovering compatible providers right so i there can be more than one provider so it should be able to see that where the compatible providers interaction usually request response right and sla violation dynamically managed and
• 10:30 - 11:00 verified so if there is a sla violation this need to be dynamically managed and verified and necessary action to be initiated of there is a violation of the sla there is a web service level agreement framework there is a concept called wa ws la web service level agreement framework so there is a framework for ah ws services formal xml schema based languages to express sla and runtime interpreter
• 11:00 - 11:30 measure and monitor qos parameter quality of ah service parameters and report violations if any lack of formal definitions for semantics of the metrics right so there are ah there is what we are talking about is more of a syntactic way of looking at there are few issues of semantics of looking at but there are lays standardization of what what the semantics of the whole thing means like whether the whole ah this parameter still something
• 11:30 - 12:00 like i can say that whether this parameter tells that the system is performing well is going down and type of things on i am expecting a failure something or this type of things may happen when this type of things so there are different underlining semantics which is ah which is did to be formally defined or standardized so if you look at ah this ws sla this as the cloud evolve from this web service and service
• 12:00 - 12:30 oriented architecture keeping those the framework in mind so obviously this slas are etcetera are also having a ah relationship with them with the things right so but if you if we look and try to see that little litigate of the what are the differences between the things ah mainly divide mainly trying to look at into three major components one is qos parameters that quality of service parameters one is automation and another is resource allocation
• 12:30 - 13:00 so these are the three thing what we are looking there so in case of qos parameter in case of a traditional web services so what we see response time sla violation for sla violation rate for reliability availability cost of services etcetera so in traditional things there is a response time plays a vital role and there are sla violation rates for reliability availability and cost of services etcetera so if there
• 13:00 - 13:30 are violation then we with there are ah what should be that there is rate that what we things will be there in case of a cloud ah qos is related to security privacy trans management etcetera have more importance right so the basic way of handling may be there but in case of a cloud we are more concerned about ah security more concerned about ah privacy trust overall management
• 13:30 - 14:00 and so and so forth if we look at the automation point of view traditional web services sla negotiation provisioning service delivery monitoring are not automated right in case of a cloud sla automation is required for high dynamic and scalable services like i can scale up scale down and thing so i dynamic and scalable services may require this monitoring resource allocation traditional web services uddi that is universal description discovery
• 14:00 - 14:30 and integration thats a uddi is one of the protocol which is very prominent in web services it provides a services and we do use those type of things in cloud also for advertising and discovering between the web services so this uddi is there in case of a cloud resources are allocated and distributed globally without any central directory perceive right so ideally it is a distributed things and there is a different mechanism of knowing
• 14:30 - 15:00 that who is having what so if we look at the different types of slas right what are the types of slas one is the observe cell or non negotiable sla or sometimes known as direct sla right so one type of things of the cell so non conductive not conducive for mission critical data or applications so it may not be ah ah if n would be suitable if you have
• 15:00 - 15:30 a if you have a very mission critical application you want to do this thing and so and so forth provider creates a sla template and define all criteria that is contract period billing responsible response time availability etcetera provides say template and all whatever the things is there it could followed by the present day state of art clouds so the this specially this public cloud follow this type of thing so whenever you want to ah buy some services
• 15:30 - 16:00 from the public cloud it will it will go you this so with this form with other terms and condition so you need to agree on the things to work on the things right whereas negotiable sla that means ah you negotiate and find out that what things will be there negotiable via external agent so i may have there may be external agents which negotiates between the provider and consumer and there can be negotiable via multiple external agent if there you are buying multiple services and then you ah amalgamate those services
• 16:00 - 16:30 to achieve one particular thing then it can be multiple layers ok so it can be so it can be either of the sell that is a standard or whatever is provided or negotiable usually what happened whenever we are having ah ah small requirement want to do ah a something which is there it in our in our own ah means some some very small
• 16:30 - 17:00 scale operations then we go for this type of the ah of self staff whenever we have a large requirement like he want to have whole organization process into the thing and etcetera then we want to look at the more have a negotiable sla so want a special rate it is as good as you are booking a ah particular hotel or transport for one or two percent then you go for that whatever is available but if you are buying the whole booking the whole hotel or the booking a transport bus or something then you have a negotiation to do that that what we have
• 17:00 - 17:30 also negotiate to have some fine tune the agreement poses so now what you are discussing about so we have slas right service level agreement and this slo slos are contributing to to from this slas right so service level objectives so objectively measurable condition for service so that is one point encompasses multiple
• 17:30 - 18:00 qos parameters so slos can have a different qos parameter like availability serviceability billing throughput response time quality etcetera so these are somewhere other need to be measured so for example may be availability of service is ninety nine point nine percent so that is a thing i can say that response time of a database query should be between three to five seconds right so that is a response time i am looking for throughput of a server particular
• 18:00 - 18:30 server at peak time should be something point eight seven five right so that may be another point of ah looking at the thing so these are this can be different type of ah slos so service level management so i have agreement i have slos now i have to manage this so monitoring and managing the performance services based on the slos so slos are reporting that what are the different values etcetera provider perspective make decision based on the business
• 18:30 - 19:00 objective and technical realities right so it has a business objective its has a business goal and technical realities how much things he the provider is having at the back end that is also important from the consumer perspective decision about how to use cloud services right so it is more that whether it is suitable for my organization where i suitable for my personal dream need etcetera then that way i measure so there are several consideration
• 19:00 - 19:30 for for slas few of them is one as we have our business level objectives responsibilities of the provider and consumer is important that means the balance of responsibility between the provider and consumer will vary according to the type of services right so there are some services where the providers responsibility is much much higher whether there is a services which are which also require the consumer responsibility right like i put some data and get output of it i may have a things that i can the consumer ah the your
• 19:30 - 20:00 provider can basically ah ah accept data as the rate of say x megabits per second and then if i send some data as i x dashed where x x dash is more than the x then there may be problem of ah things ah problem of overflow of data and type of things then which may intern violate other slas of the thing ah sla of the provider so there is a responsibility for the both the try to check and do and there are auditing
• 20:00 - 20:30 to maintain that they all are for you business continuity and disaster recovery another important aspect for the consumer should ensure that cloud providers have adequate protection in case of a disaster right it may be disaster natural manmade system failure etcetera so it should have been business there are system redundancy so many cloud provider deliver their services via massively redundant systems right so that you can get guarantee so these are some of the things which are inter lead there are other issues like maintains
• 20:30 - 21:00 maintenance maintenance of the cloud infrastructure effects any kind of cloud offering applicable to both software and hardware so maintenance is a big factor location of the data if the cloud provider premises to enforce ah premises to enforce data location regulation the consumer must be able to audit the provider to prove the regulations are being followed like and say that ah i can ah it may be so happen that iit kharagpur for example say that all my data if in cloud should be residing within the jurisdiction of india right i dont
• 21:00 - 21:30 care how so there should be a where to i verify that the data is not in some other country or some other land seizure of data if low enforcement targets that data and application associated with the particular consumer the multi tenant nature of the cloud computing makes it likely that the other consumer will be effected also like if if suppose a a consumer c one its data the law enforcement or department want
• 21:30 - 22:00 to seize then if it is residing multi tenant with some other consumer then the it may want to seize the whole at this then other things will be there so there is a issue which need to be there failure of the provider if in case of a failure of the provider what should be there and jurisdiction that any type of litigation were where it will be ah addressed there are other sla requirements like one definitely security there is a big issue of
• 22:00 - 22:30 data encryption if i encrypt the data how this key management will be there where the encrypted data will be residing where the key will be residing how the key will be communicate and etcetera privacy issue isolation of the consumer data in a multi tenant environment how to isolate a ah consumer data and services in a multi tenant environment data retention and deletion ah right say if there is a if the how long the cloud will retain the data and where it
• 22:30 - 23:00 will delete and type of things hardware erasure or destruction so provider requires to zero out the memory if consumer powers of the vm or even zero out the platters of the disk if it is to be disposed or recycled so if there is a thing as that the hardware erasure or disposing of the hardware etcetera then what will be the other effect on the things so this things need to be there there are several other requirements one may be one is regulatory compliance transparency
• 23:00 - 23:30 that what i am providing whether you are transparent to the consumer and the third party certification whether provider has a certification process that it provide something which is which has a particular level of granted services and certification monitoring how to how to monitor the performance of the provider that is provider should be responsible for providing certification of any kind of sorry to eliminate the conflict of interest between the provider and consumer
• 23:30 - 24:00 a neutral third party organization or what we say third party monitoring agency or third party auditor is the base solution for monitor performance so these are easy to tell about but while implementing it is very difficult because suddenly in the ah ah provider things they may not allow this third party to work on their systems etcetera right then auditability as the consumer are liable to breach ah liable
• 24:00 - 24:30 to any breaches that occur it is vital they should be able to audit provider systems and procedure right as it will affect the consumers own business if with the providers with and sla should make it clear how and when those audit takes place because audits and disrupts audits are disruptive and expensive ah provider will most likely place limits on when charges on them right so if you want to do frequent auditing then it may basically it is a expensive
• 24:30 - 25:00 both on not only on minute items it is on resource term also right there may be downtime there may be other resource requirement etcetera so provider may not be interested in that very frequently so that to be need to be properly provision there is another factor call what we component called key performance indicator right so it is low level resource metric right so multiple kpis are composed aggregated or converted
• 25:00 - 25:30 to high level slos multiple slos are integrated to have that sla so service if we look at i have sla then slo and then kpi right so a kpis is the lowest level metric which we
• 25:30 - 26:00 have so that means here is a multiple kpi composed aggregated and converted to high level slos like kpis like typically like may be downtime right uptime in bytes out bytes packet size etcetera right so these are the different ah kpi there can be there so possible mapping like if availability
• 26:00 - 26:30 is a one of the objective then availability is one minus downtime by uptime right so these are the components this kpis which are very low level and directly measure measured from the system parameters and slos ah are measured based on this kpis amd this kpi this slo aggregation of slos are these sla so industry defined kpis so monitoring so natural question who should monitor the performance
• 26:30 - 27:00 of the provider does the consumer meets the responsibility solution neutral third party organization to perform this monitoring eliminate conflicts of interest then there is issues of ah auditability as we have discussed so the metric for monitoring and auditing these are the typical widely used metrics throughput availability reliability load balancing so when elastics elasticity kicks in so new vms are booted or terminated for example then
• 27:00 - 27:30 the load balancing of the systems is a important factor right durability how likely the data to be lost how much the how much durable this data or services are there elasticity then linearity how the system performs at the load increases if it is a linear increases like load increases and the system also increases ah the system ah provisioning also increases whether it is a linear craft if it is a linear craft
• 27:30 - 28:00 then it is easy to ah scale up like easy to chase this ah higher demand if it is a non linear specially exponential etcetera then it is a difficult process we will see later on so there are few more metrics like ah agility automation customer service response time service level violation transaction time resolution time these are different other components now if we have this chart there are different requirements at different levels right like
• 28:00 - 28:30 ah iaas may requiring something paas may requiring something and saas may be requiring something on these different type of some a few of the requirement components so we will quickly look at some of these ah popular or example cloud providers slas or what they type like try to give the like amazon ec two if the iaas service provider ah it shows that the
• 28:30 - 29:00 availabilities ninety nine point five percent like service year three sixty five days annual percentage uptime region and so and so forth whereas s three which provides amazon is to provides storage as a service availability ninety nine percent with the following definition error rate monthly uptime percentage etcetera so those components those ah parameter index we can find out similarly google sales force microsoft provides iaas paas availability ninety nine point nine percents with following
• 29:00 - 29:30 definition monthly connectivity uptime service level and etcetera similarly ah zoho which provides saas rack space ah terremark so there are some of the things which are listed here so what we try to discuss in this particular talk is that this service level agreements in plays a vital role when we want to use want to make these
• 29:30 - 30:00 cloud computing in our in practice right i want to when i want to for my personal use or organizational use where when we want to migrate from my conventional traditional system to this cloud computing thing then i need to look at around ah across these different slas right what i need what are the parameters i need and whether it is whether it is measurable
• 30:00 - 30:30 ah by the at the provider ends and how i can guarantee that my work or my work process business process should not be affected adversely by the cloud service provider ok so with these we will stop here thank you