service taxonomy

8/6/2019 Service Taxonomy

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Session Objectives and Agenda

Understand the need for a Service TaxonomyUnderstand the service types defined by the Taxonomy

Their roles and characteristics

The similarities and differences between themUnderstand how service types are composed together

Describe a particular composition model of the elementsdescribed by the taxonomy (Process Driven)Hint to other models (e.g. Event Driven)

Understand how service types relate to Business & ITrelated decisions


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SOA Complexity

SOA aims to expose functional assets andbusiness processes so that they can be reused

A typical large enterprise can expect to have dozensof course-grained sets of services

Many of them are likely to use other lower-levelservices, which in turn could use even finer-grainedservices, and so on

Managing a huge toolbox of reusablecomponents is very difficult

To promote composition and reuse, we need awell structured service catalog

Without it our SOA efforts will collapse under their own weight!


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Taxonomy

A classification of things, as well as to the principlesunderlying such a classificationMathematically, a Hierarchical Taxonomy is a tree

structure of classifications for a given set of objectsContainment hierarchy

Programming Languages

.NET

C# VB

Other

C++ COBOL


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Defining a Good Taxonomy

Trucks

SedansMini Vans

StationWagons


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Solution Components

Application FrameworkBus Services

Part of the supporting distributed computing infrastructure

Functionality it is not specific to any application Application Services

Coarse grained, high-level app building blocks

Application ServicesCommunication

Services

UtilityServices

Application Framework


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Bus Services

Communication ServicesOffer message transfer facilitiesE.g. message-routing, publish-subscribe,

Utility ServicesOffer capabilities unrelated to message transfer E.g. service-discovery, federated-identity,

Application Services

CommunicationServices

UtilityService

s

Service Authoring Framework


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Entity ServicesManipulate business entitiesE.g. Employee, Purchase Order, Conveyer Belt

Capability Services and Activity ServicesFunctional building blocks of the applicationE.g. Check Vacation Eligibility, Verify Customer Credit

Process ServicesCompose and orchestrate Entity, Capability and ActivityServices to implement business processesE.g. Authorize Vacation, Process Purchase Order



UtilityService

s



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Sample CompositionProcess Driven Solution

Process

Capability

Activity

Capability


UtilityServices

Discovery

STS

Sc ema appin

Routin PublisSubscribe Queuin

Activity

Clou

EntityEntity

Activity Capability

Entity

BizTalk, WCF, WF, S Q


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Communication Services

RoleTransport messagesInto, out of, and within the system

Across network or protocol boundaries

Not concerned with the content of the messagesMessage schema agnosticMay use message parts to determine message advancement

ExamplesRelays, pub-sub, routers, queues, gateways



UtilityService

s



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InterfacesGeneric interface for receiving & forwarding messagesInterface is message-schema agnostic

Management and possibly monitoring interfaces

Management Monitoring

CommunicationService


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CharacteristicsCharacteristic Details

State Management No app state. Self state configured by the

applicationMonitoring &Diagnostics

Analysis of message traffic patterns. Error ratereporting

Security App-specific requirements, regulatory, etc. withpermissions at App, User, or App-User

Errors Network level (e.g. round robin)

Construction &Management

A commodity (build centrally or buy) thats builtto last and is centrally managed


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Utility Services

RoleGeneric, non-messaging, app-agnostic services

E.g. STS, discovery, message schema translation, etc.

Configured on how to perform operations for the appE.g. schema mapping for schema translation service



UtilityService

s



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Utility Services

Interfaces An interface specific to the service functionalityProcesses messages sent to itMessage exchange is typically request-response

May also have management and monitoring interfaces

UtilityService

Management Monitoring

FunctionalInterface


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Utility Services


State Management No app state. Self state configured by the

applicationMonitoring &Diagnostics

Analysis of service requests. Error ratereporting

Security App-specific requirements, regulatory, etc. withpermissions at App, User, or App-User

Errors Errors handling is specific to the servicesfunctionality


A commodity (build centrally or buy) thats builtto last and is centrally managed


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(Recap)Entity ServicesManipulation of business entitiesE.g. Employee, Purchase Order, Conveyer Belt

Capability Services and Activity ServicesFunctional building blocks of the applicationE.g. Check Vacation Eligibility, Verify Customer Credit

Process ServicesCompose and orchestrate Entity, Capability and ActivityServices to implement business processesE.g. Authorize Vacation, Process Purchase Order



UtilityService

s



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Entity Services

RoleUnlock and surface the business entities in the systemData-centric components ("nouns") of the business processExpose the information stored in one or more data stores in thesystem through a service interface

Abstract data storese.g. SQL Server, Active Directory, etc.

The information being managed is of general interestUsed in several or even all the systems in the organization



UtilityServices



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Entity Services

InterfacesCRUD interface at the entity levelOperations may depend on access & modification restrictionsEntities are structured typesUnderlying data stores typically relational or hierarchical

Additional domain-specific operations Addressing problem-domainSupport apps features & use-cases

E.g. FindCustomerIdByCriteria

EntityService

FunctionalInterface

(CRUD + domainspecific)


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Capability Services

RoleRepresent business-level capabilities of the org Action-centric building blocks of the organizationsbusiness processes

Atomic verbs"Can be further divided by the type of service that theyprovide

By business function: Financial, ERP, Mfg., etc.By type: 3rd-party interfacing, internal/unique to business, etc.Etc.



UtilityServices



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Capability Services

InterfaceInterface specific to the capability they representMay thinly wrap an existing (legacy) or newly acquiredbusiness capability

Faade service is opaqueUnderlying capability can be replaced without changing theservice interface used to access itFaade service is considered the Capability ServiceUnderlying capability becomes an implementation detail

CapabilityService

FunctionalInterface

ExistingCapability

NewCapability

Service

FunctionalInterface


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Capability Services


State Management Manage transient state, for shorter than the

duration of the processConsistency Atomic TX (flowed downstream) & Reservation

pattern (over downstream store)

Security App-specific access restriction requirements,regulatory, etc. Permissions at App level

Errors Error compensation part of SLE/SLA


Built /Buy/Lease to last (workflow or code).Used by multiple apps & centrally managed


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Activity Services

RoleBusiness-level capabilities or action-centric businesslogic elements (building blocks)

Used in a single composite-app or a single solutionMay evolve into Capability Services

Forces impacting creation of Activity ServicesDecomposition of a complex processEnabling reuse of functionality in several places

Within a single Process Service or acrossdifferent Process Services

Forces can stem from a variety of sources

Architectural/implementation requirements,organizational forces, security requirements,

regulatory requirements, etc.



UtilityServices



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Activity Services

InterfaceService interface is specific to the capabilityIt is possible for an Activity Services to wrap an existingunit of functionality

Especially in Lift and Shift cases

ActivityService

FunctionalInterface

ExistingFunctionality

New

ActivityService

FunctionalInterface


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Activity Services


State Management Manage transient state. Wrapping cases will

actually hold app stateConsistency Atomic TX (used internally) & Reservation

pattern (with wrapped system)

Security App-specific access restriction requirements,regulatory, etc. Permissions at App level

Errors Error compensation part of SLE/SLA


Built in-house to last (workflow or code). Usedby single apps & managed accordingly. Over time may transition into a Capability


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Process Services

RoleCombine data-centric and action-centric building blocksto implement business processes

Compose the functionality of Activity Services, CapabilityServices, and Entity Services and tie them together withbusiness logicDesigned to enable process agility

May be composed into the workflows of other ProcessServices

Are not be re-categorized as Capability or Activity Services dueto their long-running nature and the fact that they implement anagile process



UtilityServices



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Process Services

InterfacesOften fronted with a user interface that initiates,controls, and monitors the process

Service interface typically geared towards consumption by thepresentation layer Provides the right level of granularity required to satisfy the usecases that the user-facing front-end implements

Monitoring the business process (BAM)

ProcessService

FunctionalInterface

Monitoring


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Process Services


State Management Manage app state for the duration of a the

process implementedConsistency None or Reservation pattern (if recomposing)

Security User-specific access restrictions

Errors Error handling is an integral part of the processbegin implemented


Built in-house to change (workflow). Used by asingle app & managed per-app. May berecomposed into another process


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Service Taxonomy Summary

Category State Security Errors Build/Buy Mgmt.

Messaging Self N/A Limited Buy Centralized

Utility Self User/App Limited Buy Centralized

Entity System User/App Limited Build CentralizedCapability None/Self App Meet SLE/A B/B/Lease Centralized

Activity None/Self App Meet SLE/A Build Per app

Process Process User Biz Logic Build Per app


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Presentation Summary

For the architect, having a good grasp of the differentcategories helps with:

Classifying existing or new servicesDefining the proper functionality to include in a particular

service in order to promote composition and reuseFor IT & BDM, understanding the business value of acomponent and its commoditization level

Affects build vs. buy vs. lease decisionsMay expose opportunities for making a service available for

others as a SaaS offering

For more details on this topics see my article in the Architecture Journal


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Call to Action

Catalogue your existing servicesEnhance the Taxonomy to fit your needs

Subclass the taxonomy categories as needed

Split categories with many services using finer granularity

E.g. Sales related entities vs. Manufacturing related entitiesCreate orthogonal categories for services to help discoverabilityNot a parallel service taxonomy!

Attributes that cut across taxonomy categoriesE.g. Customer related services vs. Partner related services

Give us feedbackHow can we make this more useful for you?Would you like to see us using this taxonomy in our product planningprocess? If so, how?


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Resources

T echnical Communities, Webcasts, Blogs, Chats & User Groupshttp://www.microsoft.com/communities/default.mspx

Microsoft Learning and Certificationhttp://www.microsoft.com/learning/default.mspx

Microsoft Developer Network (MSDN) & T echNethttp://microsoft.com/msdnhttp://microsoft.com/technet

T rial Software and Virtual Labshttp://www.microsoft.com/technet/downloads/trials/default.mspx


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service taxonomy

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