1. Hypermedia*Driven
Orchestration4in4Microservices
Irakli4Nadareishvili * @inadarei
Director(of(Strategy,(API(Academy
March,42015

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Marc Andreessen

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Marc Andreessen

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Marc Andreessen
“This%is%a%pattern%that%we%love%
to%fund:%unbundle X%from%Y,%
but%then%use%the%liberation%of%
X%as%leverage%to%do%amazing%
new%things%with%X.”#

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“Unbundling”

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«unbundled#by»

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«unbundled#by»

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«unbundled#by»

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«unbundled#by»

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Irakli(Nadareishvili – @inadarei
Hypermedia*Driven
Orchestration4in4Microservices

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What are “Microservices”?

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MartinFowler:
O http://martinfowler.com/articles/microservices.html
“We(cannot(say(there(is(a(formal(
definition(of(the(microservices
architectural(style,(but(we(can(attempt(
to(describe(what(we(see(as(common(
characteristics(for(architectures(that(fit(
the(label.(

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EVOLUTIONARY4DESIGN
CharacteristicsofaMicroserviceArchitectureperFowler:
COMPONENTIZATION4VIA4SERVICES
ORGANIZED4AROUND4BUSINESS4CAPABILITIES
PRODUCTS,4NOT44PROJECTS
SMART4ENDPOINTS4AND4DUMB4PIPES
DECENTRALIZED4GOVERNANCE4&4DATA4MANAGEMENT
1
2
3
4
5
INFRASTRUCTURE4AUTOMATION/DESIGN4FOR4FAILURE6
7

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We KnowWhat It Is Not:
Monolith

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We KnowIt Is Popular:

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It is notjust abouttechnology

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Unbundling:greatestdisruptor of tech industry
“Microservices unbundle'your%business%
for%internal%and%[controlled]%external%
disruption”#
– Irakli#Nadareishvili

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MicroserviceArchitecture
iscomplex
Uncomfortable truth:

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Monolithis brittle,but has order

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Microservices:High Degree of Freedom

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Mostof us arequiteawful at
designingdistributedsystems.
Uncomfortable truth:

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EVOLUTIONARY4DESIGN
CharacteristicsofaMicroserviceArchitectureperFowler:
DECENTRALIZED4GOVERNANCE4&4DATA4MANAGEMENT5
7

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Watch-outfor tightcoupling!

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Wecan buildloosely-coupled,
evolvableservices,by designing
themas HypermediaAPIs
Solution we know works:

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HypermediaperFielding
Architectural(Styles(and(the(Design(of(NetworkObased(
Software,(2001
O Roy(T.(Fielding
“Hypermedia(is(defined(by(the(
presence(of(application(control(
information(embedded(within,(or(
as(a(layer(above,(the(presentation(
of(information

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Or: response= data+ controls
API(server(would(have(to(send(client(
not(just(static data,(but(also(controls(
describing(API(affordances.

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Challengeby IosebDzmanashvili:
Most(common(hypermedia(
controls(facilitate(“a(single(step”.

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Howdo we orchestrate
Loosely-coupledmicroservices
for complexworkflows?

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#REM:response= data+ controls
API(server(would(have(to(send(client(
not(just(static data,(but(also(controls(
describing(API(affordances.

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Affordances
Theory(of(Affordances,(1979
O James(J.(Gibson
Affordances(are(all("action(possibilities"(
latent(in(the(environment.

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Affordances

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Affordances

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Affordances’rekeyto a gooddesign
Imagine(a(car(or(a(building(that(you(couldn't(possibly(
use,(unless(you(had(a(manual.(That(sounds(silly,(we(
don't(build(cars(or(buildings(like(that.(Yet,(that(is(
exactly(how(we(build(APIs(today.

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Recognizable Affordances

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Commonality MakesAffordances Obvious
Are(all(cars(exactly(the(same?(No.(Can(we(do(basic(things(
with(any(car,(once(we(understand(how(cars(in(general(work?(
Yes!(Do(we(need(to(read(a(manual(for(that?(No!

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Identify and standardize
commonset of affordances
We need to:

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E*COMMERCE
BOOKING4TRAVEL1
2
Examples:

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BookingTravel

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Diagram(by:(Clemens(Vasters
source:(http://vasters.com/clemensv/2012/09/01/Sagas.aspx
Saga: Long-LivedCompensating Transactions

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Link RelationsforSaga:
• rel =(“routingOslip”((new:(microformats)
• rel =(“compensatingtx”((new:(microformats)
@see:(http://rels.messages.io

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E-Commerce

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BROWSING/DISCOVERY4–“HYPERMEDIA4MAZE”4(AMUNDSEN)
CHECKOUT4– SERVICE4ORCHESTRATION
POST*PURCHASE4–SERVICE4CHOREOGRAPHY
1
2
3
3 Typesof ComplexWorkflows

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MazeProblems

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Maze+XML

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Checkout:Orchestration
Checkout
1.(Collect(Shipping(Info 2.(Billing(Info 3.(Authorize(Payment
4.(PostOpurchase(processing

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OrchestrationforWizard-StyleWFs:
• rel =(“next”
• rel =(“prev”
Standard(IANA(link(relations:

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PostPurchase:Choreography
PostOPurchase(
service
Shipping(Service
EOmail(notification(service
SMS Notification(Service
Purchase(
Completed(
event
Push(Notification(Service
«subscribes#to»

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ServiceChoreography
• rel =(“hub”((IANA(standard)
• rel =(“sub”((new:(microformats)
• rel =(“unsub”((new:(microformats)
• rel =(“events”((new:(microformats)
Async and(eventOdriven.(
Standard:(Pubsubhubbub
@see:(http://rels.messages.io

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BROWSING/DISCOVERY4–“HYPERMEDIA4MAZE”4(MIKE4AMUNDSEN)
CHECKOUT4– SERVICE4ORCHESTRATION
POST*PURCHASE4–SERVICE4CHOREOGRAPHY
1
2
3
Typesof ComplexWorkflows
DISTRIBUTED4TRANSACTIONS4–SAGA4(HECTOR4GARCIA*MOLINA4&4KENNETH4SALEM4)4

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Are theremoreworkflowtypes?
Probably,but: next time!

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Microservices❤ Hypermedia-DrivenOrchestration
Photo(credit:(Corey(Seeman,( CC(BYONCOSA( 2.0.(https://www.flickr.com/photos/cseeman/14144834659

54. Director(of(Strategy,(API(Academy
Irakli4Nadareishvili
@inadarei @apiacademy @cainc
https://speakerdeck.com/irakli
linkedin.com/in/inadarei
ca.com