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Applies lean manufacturing principles across the cloud service delivery chain to enable application and infrastructure service providers to sustainably achieve the shortest lead time, best quality, and value * Applies lean thinking across the cloud service delivery chain to recognize and minimize waste * Leverages lessons learned from electric power industry operations to operations of cloud infrastructure * Applies insights from just-in-time inventory management to operation of cloud based applications * Explains how traditional, Information Technology Infrastructure Library (ITIL) and Enhanced Telecom Operation Map (eTOM) capacity management evolves to Lean Computing for the Cloud
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IEEE Press445 Hoes Lane Piscataway, NJ 08854
IEEE Press Editorial BoardTariq Samad, Editor in Chief
George W. Arnold
Ziaoou Li
Ray Perez
Giancarlo Fortino
Vladimir Lumelsky
Linda Shafer
Dmitry Goldgof
Pui-In Mak
Zidong Wang
Ekram Hossain
Jeffrey Nanzer
MengChu Zhou
Kenneth Moore, Director of IEEE Book and Information Services (BIS)
Technical Reviewers
Caroline Chappell, Heavy ReadingTim Coote, CMLStuart Curley, Northgate ISRocky Heckman, MicrosoftPaul Schuster, BPSteve Woodward, Cloud Perspectives
Eric Bauer
Copyright © 2016 by The Institute of Electrical and Electronics Engineers, Inc.
Published by John Wiley & Sons, Inc., Hoboken, New Jersey. All rights reserved.
Published simultaneously in Canada.
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Introduction
Acknowledgments
Abbreviations
1 Basics
1.1 CLOUD COMPUTING FUNDAMENTALS
1.2 ROLES IN CLOUD COMPUTING
1.3 APPLICATIONS
1.4 DEMAND, SUPPLY, CAPACITY, AND FUNGIBILITY
1.5 DEMAND VARIABILITY
1.6 CHAPTER REVIEW
NOTES
2 Rethinking Capacity Management
2.1 CAPACITY MANAGEMENT
2.2 DEMAND MANAGEMENT
2.3 PERFORMANCE MANAGEMENT
2.4 CANONICAL CAPACITY MANAGEMENT
2.5 THREE CLOUD CAPACITY MANAGEMENT PROBLEMS
2.6 CLOUD CAPACITY MANAGEMENT AS A VALUE CHAIN
2.7 CHAPTER REVIEW
3 Lean Thinking on Cloud Capacity Management
3.1 LEAN THINKING OVERVIEW
3.2 GOAL
3.3 SEEING WASTE (NONVALUE-ADDING ACTIVITIES)
3.4 KEY PRINCIPLES
3.5 PILLAR: RESPECT
3.6 PILLAR: CONTINUOUS IMPROVEMENT
3.7 FOUNDATION
3.8 CADENCE
3.9 LEAN CAPACITY MANAGEMENT PHILOSOPHY
3.10 CHAPTER REVIEW
NOTES
4 Lean Cloud Capacity Management Strategy
4.1 LEAN APPLICATION SERVICE PROVIDER STRATEGY
4.2 LEAN INFRASTRUCTURE SERVICE PROVIDER STRATEGIES
4.3 FULL STREAM OPTIMIZATION
4.4 CHAPTER REVIEW
NOTES
5 Electric Power Generation as Cloud Infrastructure Analog
5.1 POWER GENERATION AS A CLOUD INFRASTRUCTURE ANALOG
5.2 BUSINESS CONTEXT
5.3 BUSINESS STRUCTURE
5.4 TECHNICAL SIMILARITIES
5.5 IMPEDANCE AND FUNGIBILITY
5.6 CAPACITY RATINGS
5.7 BOTTLED CAPACITY
5.8 LOCATION OF PRODUCTION CONSIDERATIONS
5.9 DEMAND MANAGEMENT
5.10 DEMAND AND RESERVES
5.11 SERVICE CURTAILMENT
5.12 BALANCE AND GRID OPERATIONS
5.13 CHAPTER REVIEW
NOTES
6 Application Capacity Management as an Inventory Management Problem
6.1 THE APPLICATION CAPACITY MANAGEMENT SERVICE DELIVERY CHAIN
6.2 TRADITIONAL APPLICATION SERVICE PRODUCTION CHAIN
6.3 ELASTICITY AND DEMAND-DRIVEN CAPACITY MANAGEMENT
6.4 APPLICATION SERVICE AS RETAIL ANALOG
6.5 CHAPTER REVIEW
NOTES
7 Lean Demand Management
7.1 INFRASTRUCTURE DEMAND MANAGEMENT TECHNIQUES
7.2 APPLICATION DEMAND MANAGEMENT TECHNIQUES
7.3 FULL STREAM ANALYSIS METHODOLOGY
7.4 CHAPTER REVIEW
8 Lean Reserves
8.1 WHAT IS RESERVE CAPACITY?
8.2 USES OF RESERVE CAPACITY
8.3 RESERVE CAPACITY AS A FEATURE
8.4 TYPES OF RESERVE CAPACITY
8.5 LIMITS OF RESERVE CAPACITY
8.6 IDEAL RESERVE
8.7 CHAPTER REVIEW
9 Lean Infrastructure Commitment
9.1 UNIT COMMITMENT AND INFRASTRUCTURE COMMITMENT
9.2 FRAMING THE UNIT COMMITMENT PROBLEM
9.3 FRAMING THE INFRASTRUCTURE COMMITMENT PROBLEM
9.4 UNDERSTANDING ELEMENT STARTUP TIME
9.5 UNDERSTANDING ELEMENT SHUTDOWN TIME
9.6 PULLING IT ALL TOGETHER
9.7 CHAPTER REVIEW
NOTES
10 Lean Cloud Capacity Management Performance Indicators
10.1 PERFECT CAPACITY METRICS
10.2 CAPACITY MANAGEMENT METRICS
10.3 INFRASTRUCTURE COMMITMENT METRICS
10.4 WASTE METRICS
10.5 KEY PRINCIPLE INDICATORS
10.6 COST OF POOR QUALITY
10.7 METRICS AND SERVICE BOUNDARIES
10.8 MEASUREMENTS AND MATURITY
10.9 CHAPTER REVIEW
11 Summary
11.1 CLOUD COMPUTING AS A SERVICE DELIVERY CHAIN
11.2 LEAN CLOUD COMPUTING
11.3 REIMAGINING CLOUD CAPACITY
11.4 LEAN DEMAND MANAGEMENT
11.5 LEAN RESERVES
11.6 LEAN INFRASTRUCTURE SERVICE PROVIDER CONSIDERATIONS
11.7 LEAN APPLICATION SERVICE PROVIDER CONSIDERATIONS
11.8 LEAN INFRASTRUCTURE COMMITMENT
11.9 VISUALIZING PERFECT CAPACITY
11.10 LEAN CLOUD COMPUTING METRICS
11.11 CONCLUDING REMARKS
References
About the Author
Index
EULA
Chapter 1
Table 1.1
Chapter 5
Table 5.1
Table 5.2
Table 5.3
Chapter 9
Table 9.1
Chapter 1
Figure 1.1
Cloud Computing in a Nutshell
Figure 1.2
High-Level Benefits of Cloud Computing
Figure 1.3
Cloud Service Delivery Relationships
Figure 1.4
Responsibilities in the Context of Cloud Service Delivery Relationships
Figure 1.5
Simplified Responsibilities
Figure 1.6
Topology of Simple, Sample Application
Figure 1.7
Intra-Application Workload Distribution via Load Balancing
Figure 1.8
Sample Service Latency Complementary Cumulative Distribution Function (CCDF)
Figure 1.9
Canonical Application Service Model
Figure 1.10
Canonical Shared Infrastructure Service Model
Figure 1.11
Cloud-Based Application Service Model
Figure 1.12
Supply, Demand, Consumption, and Capacity
Figure 1.13
Sample Daily Application Demand Pattern
Figure 1.14
Sample Demand Shock or Slashdot Event (Courtesy Wikipedia)
Figure 1.15
Sample of Application Demand Whipsaw
Chapter 2
Figure 2.1
Capacity Management
Figure 2.2
Demand Management
Figure 2.3
Framing Performance Management Focus
Figure 2.4
Simplified Capacity Management Processes
Figure 2.5
Traditional Capacity Management
Figure 2.6
Traditional Capacity Management in the Canonical Capacity Management Model
Figure 2.7
Capacity Management in ITIL
Figure 2.8
Services and Resources in the Context of Cloud Computing
Figure 2.9
eTOM Process Model
Figure 2.10
Three Cloud Capacity Management Problems
Figure 2.11
Horizontal Capacity Growth of Preexisting Application Instance
Figure 2.12
Vertical Capacity Growth of Preexisting Application Instance
Figure 2.13
Adding an Application Instance to Increase Online Service Capacity
Figure 2.14
Inter-Application Workload Distribution via Load
Placement
Figure 2.15
Input–Output View of Cloud Computing
Figure 2.16
Infrastructure Service Providers' Capacity Management Problems
Figure 2.17
Application Service Providers' Capacity Management Problem
Chapter 3
Figure 3.1
Lean Cloud Capacity Management Visualization
Figure 3.2
Capacity for Inventory Management and Cloud Computing
Figure 3.3
Lean Lake and Rocks Metaphor
Figure 3.4
Key Respect Boundaries
Figure 3.5
Lean Capacity Management Philosophy
Chapter 4
Figure 4.1
Application Service Provider's Capacity Management Problem
Figure 4.2
Canonical Framing of Application Capacity Management Problem
Figure 4.3
Framing the Canonical Cloud Service Delivery Chain
Figure 4.4
Lean Application Capacity Management Considerations
Figure 4.5
User Workload Placement
Figure 4.6
Infrastructure Service Provider Capacity Management Problems
Figure 4.7
Canonical Framing of Physical Resource Capacity Management Problem
Figure 4.8
Lean Infrastructure Capacity Management Considerations
Chapter 5
Figure 5.1
Relative Technology Maturities
Figure 5.2
Electricity Generation and Cloud Infrastructure Businesses
Figure 5.3
Simplified View of the Electric Power Industry
Figure 5.4
Sample Daily Electric Power Demand Curve
2
Figure 5.5
Hypothetical Electricity Dispatch Curve
3
Figure 5.6
Thermal Plants and Cloud Infrastructure
Figure 5.7
Sample Heat Rate Chart
Figure 5.8
Sample Server Power Consumption Chart
Figure 5.9
Standard Power Ratings
Figure 5.10
Sample Day-Ahead Locational Marginal Pricing
Figure 5.11
Locational Marginal Value for a Hypothetical Application
Figure 5.12
Infrastructure Demand, Reserves, and Capacity
Figure 5.13
Energy Balance
Figure 5.14
Virtual Resource Balance
Chapter 6
Figure 6.1
Application Service as a Production Chain
Figure 6.2
Application Capacity Management as an Inventory Management Problem
Figure 6.3
Inventory Management in the Canonical Capacity Management Framework
Figure 6.4
Capacity, Demand, and Inventory
Chapter 7
Figure 7.1
Infrastructure Demand Management Techniques
Figure 7.2
Application Demand Management Options
Figure 7.3
A Demand Planning Model for Lean Cloud Computing Capacity
Chapter 8
Figure 8.1
Reserve Capacity (copy of Figure 3.2)
Figure 8.2
Sample Capacity Estimates and Actuals
Figure 8.3
Capacity Lead Time
Figure 8.4
Technique versus Timeframe Reserve Capacity Overview
Figure 8.5
Recovery Time and Point Objectives
Chapter 9
Figure 9.1
Sample Input–Output Curve (copy of Figure 5.7)
Figure 9.2
Temporal Parameters for Unit Commitment
Figure 9.3
Temporal Parameters for Infrastructure Commitment
Figure 9.4
Context of Element Startup Time
Figure 9.5
Element Startup Time
Figure 9.6
Context of Element Shutdown Time
Figure 9.7
Element Shutdown Time
Figure 9.8
Sample Small Cloud
Figure 9.9
Hypothetical Commitment Schedule
Chapter 10
Figure 10.1
Metrics in the Context of Lean Cloud Capacity Management
Figure 10.2
Sample Perfect Capacity Visualization
Figure 10.3
Sample Continuous Improvement Opportunities
Figure 10.4
Sample Peak Capacities
Figure 10.5
Key Capacity Management Latencies
Figure 10.6
Delta-Epsilon Complexity Analysis
Figure 10.7
Selected Lean Cloud Capacity Management KPIs across Key Service Boundaries
Figure 10.8
Capability Maturity Spectrum
Chapter 11
Figure 11.1
Cloud Service Value Stream (copy of Figure 2.15)
Figure 11.2
Application Service Providers' Capacity Management Problem
Figure 11.3
Infrastructure Service Providers' Capacity Management Problems
Figure 11.4
Lean Cloud Computing Visualization (copy of Figure 3.1)
Figure 11.5
Capacity for Inventory Management and Cloud Computing (copy of Figure 3.2)
Figure 11.6
Simplified Capacity Management Process (copy of Figure 2.4)
Figure 11.7
Lean Capacity Management Philosophy (copy of Figure 3.5)
Figure 11.8
Infrastructure Demand Management Techniques (copy of Figure 7.1)
Figure 11.9
Application Demand Management Options (copy of Figure 7.2)
Figure 11.10
Lean Infrastructure Capacity Management Considerations (copy of Figure 4.8)
Figure 11.11
Lean Application Capacity Management Considerations (copy of Figure 4.4)
Figure 11.12
Hypothetical Commitment Schedule (copy of Figure 9.9)
Figure 11.13
Infrastructure Commitment Timeline (copy of Figure 9.3)
Figure 11.14
Sample Perfect Capacity Visualization (copy of Figure 10.2)
Figure 11.15
Sample Application Capacity Management Visualization (copy of Figure 10.3)
Figure 11.16
Lean Cloud Computing Performance Metrics (copy of Figure 10.1)
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The standard definition of cloud computing is a “paradigm for enabling network access to a scalable and elastic pool of sharable physical or virtual resources with self-service provisioning and administration on demand” (ISO/IEC 17788). This paradigm enables organizations to shift from traditional, capacity-driven operational models to lean, demand-driven operational models. This work adapts lean manufacturing principles across the cloud service delivery chain to achieve the lean cloud computing goal of sustainably achieving the shortest lead time, best quality, and highest customer delight at the lowest cost.
Traditionally, ICT systems were configured with sufficient capacity to serve the forecast demand, plus a safety margin, for the upcoming months, quarters, or perhaps even years. After configuring application and resource capacity to serve that forecast demand, further changes to the configuration were often discouraged to reduce the risk of procedural errors or expositing residual software or documentation defects which might impact production traffic. Thus, significant excess resource and application capacity were often committed that would rarely or never be used, thereby wasting both capital and operating expense. Lean computing pivots from the traditional build-for-peak, supply-oriented operating model to a just-in-time, demand-driven operating model. Lean cloud computing enables sustainable efficiency improvements that are essential when offering service into a competitive and cost-sensitive market.
This work considers lean cloud computing via three interlocking threads of analysis:
Methodically applying lean (i.e., Toyota production system) thinking to the cloud service delivery chain, especially regarding rapid elasticity and scaling. This is the focus of Chapter 3: Lean Thinking on Cloud Capacity Management, Chapter 4: Lean Cloud Capacity Management Strategy, Chapter 7: Lean Demand Management, Chapter 8: Lean Reserves, and Chapter 10: Lean Cloud Capacity Management Performance Indicators.
Applying insights from electric power generation and grid operations to cloud infrastructure operations. This is the focus of Chapter 5: Electric Power Generation as Cloud Infrastructure Analog and Chapter 9: Lean Infrastructure Commitment.
Applying insights from inventory management to cloud capacity management. This is the focus of Chapter 6: Application Capacity Management as an Inventory Management Problem.
This work considers business, architectural, and operational aspects of efficiently delivering valuable services to end users via cloud-based applications hosted on shared cloud infrastructure and focuses on overall optimization of the service delivery chain to enable both application service provider and infrastructure service provider organizations to adopt leaner, demand-driven operations to serve end users more efficiently. Explicitly considering the service delivery challenges of both the cloud service customer organizations that operate applications running on cloud infrastructure—as well as the challenges of cloud infrastructure service provider organizations that operate shared cloud resources—offers perspective and insight to enable optimizations across the entire service delivery chain to benefit cloud service providers, cloud service customers and cloud service users. The work is targeted at readers with business, operational, architectural, development, or quality backgrounds in the ICT industry to help them achieve the shortest lead time, best quality and value, and highest customer delight at the lowest cost for their service offerings. The work does not consider lean or agile development, software-defined networking (SDN), facility planning, or tradeoffs of any particular implementation technology (e.g., virtualization hypervisors versus Linux containers).
This book is structured as follows:
Basics
(Chapter 1) – this chapter lays out the key concepts that underpin this analysis: cloud computing principles and roles; demand, supply, capacity, and fungibility; and differentiating demand management, capacity management, and performance management.
Rethinking Capacity Management
(Chapter 2) – this chapter reviews traditional, ITIL, and eTOM capacity management models, and factors capacity management into two components for deeper consideration: (1) capacity decision and planning and (2) capacity action fulfillment. The chapter lays out the three fundamental cloud capacity management challenges:
Physical infrastructure capacity management
– how much physical equipment should be deployed to each cloud data center?
Virtual resource capacity management
– how much of that physical equipment should be powered on and made available to support application service providers at any point in time?
Application capacity management – how much application capacity should be online and available to service user demand at any point in time?
This chapter also frames the cloud computing service delivery chain that will be analyzed in Chapter 3: Lean Thinking on Cloud Capacity Management and in the remainder of the book.
Lean Thinking on Cloud Capacity Management
(Chapter 3) – this chapter rigorously applies lean, Toyota production system thinking to cloud computing. The lean cloud computing goal of
sustainably achieving the shortest lead time, best quality and value, and highest customer delight at the lowest cost
is underpinned by foundational principles and supported by pillars of respect and continuous improvement. These lean notions are methodically applied in subsequent chapters.
Lean Cloud Capacity Management Strategy
(Chapter 4) – this chapter methodically applies
lean thinking on cloud capacity management
of Chapter 3 to the fundamental cloud capacity management problems of Section 2.5: Three Cloud Capacity Management Problems.
Electric Power Generation as Cloud Infrastructure Analog
(Chapter 5) – modern utilities provide electricity-as-a-service with business, technology, and operational models that are analogous to cloud infrastructure-as-a-service providers. This chapter highlights key best practices from the mature electric power generation business that are applicable to cloud infrastructure service providers.
Application Capacity Management as an Inventory Management Problem
(Chapter 6) – online application capacity can usefully be imagined as an inventory of regenerative assets maintained by an application service provider to serve user demand. The rapid elasticity of cloud virtual infrastructure enables the application service provider to pivot from a traditional supply/capacity-driven operational model to a demand-driven operational model. This chapter highlights best practices from lean, just-in-time inventory management that are applicable to application service providers.
Lean Demand Management
(Chapter 7) – this chapter considers how various demand management techniques, including several from the power industry discussed in Chapter 5: Electric Power Generation as Cloud Infrastructure Analog, can be applied to cloud to support the key lean principle of leveling the workload.
Lean Reserves
(Chapter 8) – some safety, spare, or reserve capacity is necessary to assure acceptable service quality across random variations in patterns of demand, failures, and other unforeseen situations. This chapter considers the use and nature of reserve capacity in detail to enable deeper understanding of the appropriate level of reserve capacity.
Lean Infrastructure Commitment
(Chapter 9) – this chapter applies the electric power industry's notion of unit commitment for optimally scheduling startup and shutdown of generating equipment from Chapter 5: Electric Power Generation as Cloud Infrastructure Analog to cloud minimize
excess online infrastructure capacity
(Section 3.3.3),
waste heat
(Section 3.3.14), and
carbon footprint
(Section 3.3.15).
Lean Cloud Capacity Management Performance Indicators
(Chapter 10) – this chapter offers objective and quantitative performance measures for lean cloud capacity management which can be used to methodically drive continuous improvement of lean cloud computing deployments.
Summary
(Chapter 11) – this chapter connects all of the analyses and threads of lean cloud computing considered in earlier chapters in a crisp summary.
Cross-references are included throughout the text to help readers follow analysis through to insights and recommendations. An Index, Abbreviations, and References are also included.
Mark Clougherty provided critical review and keen insights on all aspects of this work. Andrew Lange, John Haller, Deb McCarthy, Peter Spencer, Jose De Francisco Lopez, Frederik Vandeputte, Elissa Matthews, Randee Adams, Bernard Altmeyer, Cathy Waters, Senthil Kumar Dhandapani, Alesandra Sala, Roger Maitland, Rich Sohn, John Foley, and John Scaldaferri provided valuable comments and feedback.
This work benefited greatly from thoughtful and detailed reviewer feedback from Tim Coote, Stuart Curley, Paul Schuster, Caroline Chappell, Rocky Heckman, and Steve Woodward.
BHCA
busy hour call attempts
BSS
business support system
CapEx
capital expense
CCDF
complimentary cumulative distribution function
CDF
cumulative distribution function
CI
configuration item
COTS
commercial off the shelf
DA
day ahead
DBMS
database management system
DNS
domain name system
DOA
dead on arrival
DPM
defects per million
EcoMin
economic minimum
EMS
element management system
EoR
end-of-row Ethernet switch
EPO
emergency power off
eTOM
TM Forum's Service Management Framework
ETSI
European Telecommunications Standards Institute
FCAPS
fault, configuration, accounting, performance, security
hr
hour
IaaS
infrastructure-as-a-service
ICT
information and communications technologies
IP
internet protocol
ISO
International Standards Organization (ICT industry) or independent system operator (power industry)
IT
information technologies
ITIL
IT Infrastructure Library, a suite of standards of for IT Service Management
KPI
key performance indicator
KQI
key quality indicator
kW
kilowatt
LMP
locational marginal price
MIPS
million instructions per second, or sometimes meaningless information about performance of a system
MOS
mean opinion score
MW
megawatt
NERC
North American Electricity Reliability Corporation
NIST
US National Institute of Standards and Technologies
NOC
network operations center
OAMP
operations, administration, maintenance and provisioning
OpEx
operating expense
OS
operating system
OSI
open systems interconnection
OSS
operations support system
PJM
PJM Interconnection, www.pjm.com
PM
performance management
RPO
recovery point objective
RT
real time
RTO
recovery time objective (ICT industry), or regional transmission organization (power industry)
SDN
software-defined networking
SI
International System of Units
SKU
stock-keeping unit
SLA
service level agreement
SLO
service level objective
ToR
top of rack Ethernet switch
vCPU
virtual central processing unit core
VIM
the cloud service provider's Virtualized Infrastructure Manager
VM
virtual machine
VN
virtual network
VoLTE
voice over LTE
Upon completion of this chapter the reader will understand:
The standard definition, characteristics, and benefits of cloud computing
The key roles in the cloud computing ecosystem
Key concepts of application, demand, supply, quality, and fungibility
This section reviews the following key concepts that are used extensively in this work:
Cloud computing fundamentals (Section 1.1)
Roles in cloud computing (Section 1.2)
Applications (Section 1.3)
Demand, supply, capacity, and fungibility (Section 1.4)
Demand variability (Section 1.5)
Cloud computing is defined by ISO/IEC 177881 as a “paradigm for enabling network access to a scalable and elastic pool of shareable physical or virtual resources with self-service provisioning and administration on-demand.” ISO/IEC 17788 specifies the following six key characteristics of cloud computing2:
Broad network access
– “
A feature where the physical and virtual resources are available over a network and accessed through standard mechanisms that promote use by heterogeneous client platforms. The focus of this key characteristic is that cloud computing offers an increased level of convenience in that
users can access physical and virtual resources from wherever they need to work
, as long as it is network accessible, using a wide variety of clients including devices such as mobile phones, tablets, laptops, and workstations
” (ISO/IEC 17788). Operationally, this means that end users access cloud-based application services via commonly available wireless and wireline IP networks.
Measured service
– “
A feature where the metered delivery of cloud services is such that usage can be monitored, controlled, reported, and billed… The focus of this key characteristic is that
the customer may only pay for the resources that they use
. From the customers' perspective, cloud computing offers the users value by enabling a switch from a low efficiency and asset utilization business model to a high efficiency one
” (ISO/IEC 17788). When cloud customers pay only for resources that are used, application services that are engineered so cloud resource usage tracks with application service usage which tracks with application revenue can reduce business risk by better linking application service provider's costs with application service revenues.
Multi-tenancy
– “
A feature where physical or virtual resources are allocated in such a way that multiple tenants and their computations and data are isolated from and inaccessible to one another
” (ISO/IEC 17788). Multi-tenancy enables infrastructure service providers to maximize resource sharing and boost their capacity utilization.
On-demand self-service
– “
A feature where a cloud service customer can provision computing capabilities, as needed, automatically or with minimal interaction with the cloud service provider. The focus of this key characteristic is that
cloud computing offers users a relative reduction in costs, time, and effort needed to take an action, since it grants the user the ability to do what they need, when they need it, without requiring additional human user interactions or overhead
” (ISO/IEC 17788). This means that application service providers and/or automated systems working on behalf of those application operators can install, configure, and provision cloud resources to serve their applications in real time. On-demand self-service of capacity planning and fulfillment actions, coupled with rapid elasticity, enables significant reductions in fulfillment times for capacity change actions compared to traditional deployments.
Rapid elasticity and scalability
– “
A feature where physical or virtual resources can be rapidly and elastically adjusted, in some cases automatically, to quickly increase or decrease resources. For the cloud service customer, the physical or virtual resources available for provisioning often appear to be unlimited and can be purchased in any quantity at any time automatically, subject to constraints of service agreements. Therefore, the focus of this key characteristic is that cloud computing means that the
customers no longer need to worry about limited resources and might not need to worry about capacity planning
” (ISO/IEC 17788). Application service providers and/or automated systems working on their behalf can allocate and release infrastructure resources on-the-fly, thereby enabling applications to transform from allocating and configuring capacity based on peak forecast demand (which may never even be approached) to just-in-time, demand-driven capacity configuration.
Resource pooling
– “
A feature where a cloud service provider's physical or virtual resources can be aggregated in order to serve one or more cloud service customers… From the customer's perspective, all they know is that the service works, while they generally have no control or knowledge over how the resources are being provided or where the resources are located. This offloads some of the customer's original workload, such as maintenance requirements, to the provider
” (ISO/IEC 17788). Resource pooling, coupled with multi-tenancy, enables cloud service providers (CSPs) to leverage economies of scale to boost operational efficiencies beyond what has traditionally been feasible.
Figure 1.1 offers a simplified view of cloud computing: many different applications simultaneously share a large and flexibly configured pool of compute, memory, storage, networking, and functional component resources offered by a CSP. Coupling on-demand self-service and rapid elasticity enables application service providers to fundamentally transform their businesses from configuring application capacity to meet peak forecast demand to just-in-time, demand-driven capacity management. Using measured service as the basis of charging application service providers for their resource usage enables at least a portion of the application provider's costs to shift from being fixed and independent of usage to variable so that resource charges are tied to resource usage, which is tied to application service usage, which should be tied to application revenue.
Figure 1.1 Cloud Computing in a Nutshell
Figure 1.2 visualizes key high-level business benefits of cloud computing:
Lower infrastructure CapEx
– the peak
aggregate
demand for compute, storage, and networking resources is smaller than the sum of peak demand of each individual application. Infrastructure resource sharing enables less total hardware to be deployed than with traditional operation models, and thus capital expense (CapEx) can be saved. Also, consolidating operation of that shared infrastructure enables efficiencies that can reduce operating expense (OpEx).
Infrastructure available on demand
– the ability of application service providers to allocate and release infrastructure resources on-the-fly enables agile, just-in-time application capacity management to minimize the twin business risks of over investing in application capacity that is never used (if demand forecasts are too optimistic) or being unable to serve customer demand (if demand forecasts are too conservative).
Lower infrastructure OpEx
because a single infrastructure service provider can operate and maintain shared infrastructure cheaper than each application service provider can operate and maintain their own private infrastructure. In addition, consolidating active resource loads onto the smallest number of physical elements enables unneeded capacity to be turned off.
Application OpEx for infrastructure tracks with resource usage
thereby derisking application service provider businesses by having their OpEXs for resource capacity track with service usage, and thus hopefully with revenue.
Figure 1.2 High-Level Benefits of Cloud Computing
Cloud enables disruption of IT service management in several ways:
Encourage agile, incremental development and deployment models
– these practices can reduce the organization's business risks around development activities by enabling applications and services to be developed and deployed via smaller project tasks which can generally be better managed rather than relying on massive software projects that are harder to manage.
Elastic capacity enables new operational models for application release management
– infrastructure available on-demand means that instead of relying on complex software upgrade, update, or retrofit procedures that must execute “in-place” on traditional hardware, an independent set of infrastructure resources can be allocated to host the new software upgrade, update, or retrofit and that release maintenance action can largely proceed without impacting the production instance thereby both reducing service risk for users and operational complexity (and presumably costs) for application service providers.
Fungibility of virtualized resources enables workload aggregation
– virtualization enables commodity physical compute, memory, and storage resources to be configured on-the-fly to serve a huge range of applications. Thus, rather than planning, installing, and allocating explicit physical resources to dedicate to each application in advance, a pool of commodity hardware can be created, with virtual resources allocated to applications on-the-fly.
Virtual resources are ephemeral
– application service providers can allocate and deallocate virtual resources as needed to better align their resource usage – and thus presumably their resource costs – with service usage which is presumably linked to their revenue. Leveraging ephemeral resources and usage-based resource pricing to better align costs with revenue is fundamentally different from the traditional model where resource (i.e., infrastructure equipment) costs are a sunk cost for the application service provider to manage.
Virtual compute, memory, storage, and networking resources released by applications can easily be reallocated to other applications
– virtualization increases the fungibility of physical infrastructure resources by enabling physical resources to emulate a range of resource configurations that might be desired by application software. Greater fungibility means that each type of physical resource can serve a broader range of application needs, thereby permitting more efficient resource utilization.
Automation of virtual resource management and orchestration can:
yield short and consistent lead times for application capacity management changes;
yield more reliable application capacity management changes;
lower fulfillment costs per capacity management change action.
On-the-fly virtual resource allocation and operations enables aggressive power management
– this topic is detailed in Chapter 9: Lean Infrastructure Commitment.
Figure 1.3 visualizes the primary ISO/IEC 17788 roles in cloud computing:
Cloud Service User
is an end user, or an application operating on their behalf, who enjoy cloud services such as social networking applications or watching streaming movies.
Cloud Service Customers
(CSCs) are organizations that operate cloud services for cloud service users, such as an organization that offers streaming entertainment or real-time communications services to end users via cloud-based applications. For example, a company that offers streaming movie services to end users by deploying their application software onto some other organization's infrastructure-as-a-service (IaaS) offering is a CSC. This role is analogous to NIST SP 500-292
Cloud Consumer
. As the notion of customer or consumer often creates confusion, this book will refer to this role with the more commonly used term
application service provider
.
Cloud Service Provider
(CSP) is broadly defined by ISO/IEC 17788 as a “
party which makes cloud services available
”; this role is analogous to NIST SP 500-292
Cloud Provider
. Some CSPs offer virtualized compute, networking, storage, and memory resources to application service providers (CSCs) as IaaS offerings. Virtual compute, memory, storage, and networking can be offered by infrastructure service providers to application service providers via technologies such as hypervisors, Linux containers, and other virtualization mechanisms. For convenience, this paper will refer simply to virtual machines (VMs) as the primary unit of infrastructure capacity, so this should be understood to cover Linux containers and other implementation options as well. ISO/IEC 17789 defines
functional component
as “
A functional building block needed to engage in an activity, backed by an implementation
”; some CSPs will offer functional components such as databases or load balancers to consumers via platform-as-a-service offerings. While there is some disagreement across the industry regarding exactly what functionality offered as-a-service should be classified as platform-as-a-service versus software-as-a-service (or even IaaS), the exact taxonomy is unimportant for this analysis. For simplicity, this book will refer to this role as
infrastructure service provider
. Note that there may actually be multiple service provider organizations, such as one organization operating virtualized compute, memory, storage, and networking infrastructure and another organization operating higher-level functional components like database-as-a-service, but that distinction is also unimportant for this analysis.
CSP: Network Provider
is defined by ISO/IEC 17789 as a party which “
may provide network connectivity between systems within the cloud service provider's data centre, or provide network connectivity between the cloud service provider's systems and systems outside the provider's data centre, for example, cloud service customer systems or systems belonging to other cloud service providers.
” This role is analogous to NIST SP 500-292
Cloud Carrier
.
Cloud Service Partners
(CSN) are defined by ISO/IEC 17788 as a “
party which is engaged in support of, or auxiliary to, activities of either the cloud service provider or the cloud service customer, or both
.” The three partner roles enumerated in ISO/IEC 17789 are:
Cloud Service Developers
are “
responsible for designing, developing, testing and maintaining the implementation of a cloud service
” (ISO/IEC 17789). This book will generally refer to this role as
software suppliers
.
Cloud Auditor
defined by ISO/IEC 17788 as a “
Cloud service partner with the responsibility to conduct an audit of the provision and use of cloud services
.” This role is analogous to NIST SP 500-292
Cloud Auditor
. This role is not shown in
Figure 1.3
and this book will not consider this role.
Cloud Service Broker
defined by ISO/IEC 17788 as a “
cloud service partner that negotiates relationships between cloud service customers and cloud service providers.
” This role is analogous to NIST SP 500-292
Cloud Broker
. This role is not shown in
Figure 1.3
and this book will not consider this role.
Figure 1.3 Cloud Service Delivery Relationships
Note that the primary service relationships among roles visualized in Figure 1.3 are shown in the style of TMF GB917 and TMF TR178 in Figure 1.3. The application service provider offers valuable services to end users which are delivered across one or more CSP network providers' (or cloud carriers') networks. The application service provider's service offering is the result of integrating one or more applications from software suppliers with virtual compute, networking, storage and memory, along with automated lifecycle management services to instantiate, operate, and manage the application instances, and perhaps some functional components offered as-a-service by one or more CSPs.
Figure 1.4 visualizes the simplified responsibilities of the primary actors of Figure 1.3. The cloud (infrastructure) service provider organization owns and operates the pool of physical and virtual resources that are offered to various application service provider (CSC) organizations. Each application service provider organization is responsible for engineering, integration, and operation of their user facing service offering. Figure 1.5 overlays simplified responsibilities onto Figure 1.1.
Figure 1.4 Responsibilities in the Context of Cloud Service Delivery Relationships
Figure 1.5 Simplified Responsibilities
The two most common standard cloud deployment models discussed in this work are:
Public cloud
is defined by ISO/IEC 17788 as “
Cloud deployment model where cloud services are potentially available to any cloud service customer and resources are controlled by the cloud service provider. A public cloud may be owned, managed, and operated by a business, academic, or government organization, or some combination of them. It exists on the premises of the cloud service provider.
”
Private cloud
is defined by ISO/IEC 17788 as “
Cloud deployment model where cloud services are used exclusively by a single cloud service customer and resources are controlled by that cloud service customer. A private cloud may be owned, managed, and operated by the organization itself or a third party and may exist on premises or off premises.
”
Cloud service users do not care – and often do not even know – if the application that they enjoy is hosted on a public or private cloud. The distinction of public or private cloud is of practical importance for both the application service provider and the organization that owns and operates the shared cloud infrastructure as it drives the governance and business model for the relationship between those organizations.
Application is defined by ITIL as software that provides Functions that are required by an IT Service. Applications are composed of software components that execute on physical compute, networking, memory, and storage equipment. An application instance is an operational configuration of application software components on appropriate compute, networking, memory, and storage infrastructure elements that can offer service to users.
Figure 1.6 shows a logical topology diagram of a sample application. As will be discussed in Section 2.5.3.1: Scale Capacity of a Single Application Instance, online application capacity can be adjusted by independently configuring the number of online application logic (AppLogic) instances and application storage (AppStorage) instances. Note that the sample application is architected to have only a single pair of frontend components to distribute user workload across the pool of AppLogic component instances, and a single pair of operations, administration, maintenance, and provisioning (OAMP) components manages all of the application's component instances.
Figure 1.6 Topology of Simple, Sample Application
Workloads within an application instance can often be distributed across pools of component instances, which this paper will call load balancing. Our sample application supports two levels of intra-application load balancing: the active Frontend component balances user workload across the pool of available AppLogic components (illustrated in Figure 1.7