Agile Architecture
description
Transcript of Agile Architecture
Agile Architecture
OdessaJohannes Brodwall, Chief scientist
Exilesoft Global
What is an architect?From greek Arkhi-Tecton
Tecton: BuilderArkhi: Chief.
Like “Arch angel”Or “Arch nemesis”
What is an architect?“Chief builder”
What is an architect?(Exilesoft definition)
A solution architect is someone who understands the problem of
the customerand uncovers and communicates
a feasible solution
A solution architect is someone who understands the customer’s problem
(including contraints, context, domain knowledge) and uncovers (though a
team effort) and communicates (with credibility) a feasible solution
(primarily, but not exclusively technical)
Uncover problemvision, stakeholders, usage flow
Describe problemcontext and domain model
Describe solutiondeployment, implementation model
Simplify architecturefeature oriented structure
Deliver softwarerainbow plans
• Describing architecture• Simplifying architecture• Delivering architecture
• Delivering software
• Delivering architecture
Part I:
Describing architecture
• Understanding problem• Uncovering solution
• Communicating architecture
Understanding the problem
(Tool time)
For some stakeholderWho has a goal
The Odessa agile user group (?)Is a type of activity
Which gives a capability.
Unlike most relevant alternativeThis has a distinguishing attribute.
For __________________Who ________________
The Odessa agile user group (?)Is a _________________
Which ________________.
Unlike ______________________This _______________________.
Example«Smidig» conference application
Example vision statement
For Agile practitionersWho need to expand on their experience and
networkThe Smidig conference
Is a networking eventWhich connects you with other Agile practitioners.
Unlike traditional conferencesThis presents the experience of many people
through lightning talks.
For Conference organizersWho want to organize a good conference
The Smidig conference appIs a web application
Which eliminates unnecessary work.
Unlike commercial conference appsThis is optimized for the large number of talks we have and allows us to make changes fast.
Example stakeholders
Speaker
Description• Experienced• New speaker• PassionateDuties• Register talk• Upload slide• Give talkValues• Constructive feedback
on talk• Easy CfP• Fast answer
AttendeeDescription• Knows about agile• Works in project• NorwegianDuties• Pay for conference• Get approval to go
Values• Easy registration
OrganizerDescription• Volunteer• Works in evenings• Has networkDuties• Select talks• Follow up
paymentsValues• Easy selection process• Good information overview• Never lose a participant• Financial transparency
Sponsor
Description• Busy• Manager• Not very interested
Duties• Provide logo• Pay sponsorship
Values• Informal
communication• Easy evaluation
Example usage flow
Attendance
1. Agile project practitioner wants to learn2. Attendee goes to Smidig website3. Attendee registers4. Attendee pays5. Attendee receives confirmation mail6. Organizer can see the registration7. Organizer sends reminder email to attendee to come8. Organizer prints badges for attendees9. Attendee shows up at Smidig and has an excellent
time
Speaker
1. Agile experts wants to share knowledge2. Potential speaker goes to Smidig website3. Potential speaker registers personal info4. Potential speaker registers talk5. Potential speaker receives registration confirmation email6. Organizer sees registered talk and can market speaking
opportunities7. Organizer accepts talk for confence8. Speaker receives acceptance email
– Alternative: Speaker withdraws talk – organizer updates the talk and selects another
9. Organizer prints badges for speakers10. Speaker shows up at Smidig and gives talk
/Understanding the problem
Uncovering a solution
Example context model
Smidig2011.no
Participant Speaker
Organizer
Printing company
Paypal
Example domain model
User• Name• Email• Company• Phone• Password• Accepts email?
Registration• Ticket type• Price• Paid amount• Paypal ref• Payment date• Invoice address [optional]
Talk• Title• Description• Tags[]• Slide file• Status : {pending, accept,
reject}• Email_sent• Position
Speaker*
*
Comment• Title• Text• Created date
*
*
Period• Stage• Title• Time of day• Day
Example deployment model
HerokuSmtp.dreamhost.com
Paypal
PostgreSQL
Smidig-conference
(Rails)
Web user
Developer
smidigdb
git.herokugithub
git pushgit pushgit pull
html/http
http
smtp
Example implementation
diagram
Browser Smidig2012.no Paypal.com
1. POST /users
2. Redirect to paypalwith return_url and notify_url
3. Perform payment
4. POST /payment_notifications
5. Redirect to return_url
5. GET /user/<id>
Update user info
Show user info
Save user info
/Uncovering a solution
Communicating a solution
VisionStakeholders
Usage flowContext
Domain modelImplementation
Deployment
Does the architect have to do this
herself?
Team effort
/Communicating a solution
/Describing architecture
Part II:
Simplifying architecture
• Lasagna architecture• Feature oriented architecture
• Deployment constraints
Lasagna architecture
Person-Controller
Person-Controller-
Impl
Person-Service
Person-ServiceImpl
Person-Repository
Person-Repository
Impl
PersonDao
PersonDaoImpl
Session-Factory
Controllers
Services
Managers
Workers
Repositories
Controllers
Services
Managers
Workers
Repositories
DTO
Domain
Mapping
Customer
Invoice
Order
Product
Tidying up art (Ursus Wehrli)
Feature oriented architecture
Coherence• What changes together
lives together
Tolerance• What should be different
can be different
Meaning• What is central in domain
is central in code
Your thinking is contrained by
technology fashion:
Controllers
Services
Managers
Workers
Repositories
DTO
Domain
Mapping
Your solution is constrained by
deployment
Web Application
Web user
Database
Browser
JSON/http
Web Service
SOAP
Web ServiceService
Consumer
DTO?DTO
DTO
Controller
Web Application
Web user
Database
Browser
JSON/http
DTO?Controller
DAO
Web Application
Web user
html/http
Database
Controller
DAO
Web Application
Web user
html/http
Database
Reverse proxy
html/http
Controller
DAO
Web Application
Web user
Database
Rich client
Objects over http
DTO
DTOController
Web Application
Web user
Database
Rich client
Web service
DTO
DTO
Service
Consumer
Controller
Web Application
Web user
Database
Browser
JSON/http
Web Service
SOAP
Service
Consumer
DTO?DTO
DTO
External client
Controller
DAO
Web Application
Web user
Database
Browser
JSON/http
Service
External client
DTOController
DAO
/Simplifying architecture
Part III:
Delivering software
• Common sprint problems• Demo driven development
• Rainbow plans
Common Sprint problems
User stories without context
Every feature must be perfect at first try
Users don’t understand the demo
One-sentence Scrum
We demonstrate progress at regular intervals
It’s all about the demo
We demonstrate progress at regular intervals
Progress towards what?
Usage flow
1. Something happens in the real world2. The event is communicated to the system3. The system does something4. Someone does something with the system5. …6. …7. …8. …9. …10. Some goal is achieved
Rainbow plan
Usage flow: frugalflights.com1. A customer wants cheap vacations2. The customer signs up for daily or weekly notifications of special flight
offers3. Periodically the System checks which customers should get notifications4. The System checks for offers that matches the customer’s travel
preference by looking up flights with the travel provider system5. The System notifies customer of any matching offers via SMS
• Variation: The System notifies customer of any matching offers via email6. The customer accepts the offer via SMS
1. Variation: The customer accepts the offer on the system website7. The System books the tickets on behalf of the customer8. The system confirms the booking by sending an SMS to the customer9. The customer can at any point see their active offers and accepted
offers on the system website10. The customer enjoys a cheap vacation!
What would you do in Sprint 1?
Usage flow: frugalflights.com1. A customer wants cheap vacations2. The customer signs up for daily or weekly notifications of special flight
offers3. Periodically the System checks which customers should get notifications4. The System checks for offers that matches the customer’s travel
preference by looking up flights with the travel provider system5. The System notifies customer of any matching offers via SMS
• Variation: The System notifies customer of any matching offers via email6. The customer accepts the offer via SMS
1. Variation: The customer accepts the offer on the system website7. The System books the tickets on behalf of the customer8. The system confirms the booking by sending an SMS to the customer9. The customer can at any point see their active offers and accepted
offers on the system website10. The customer enjoys a cheap vacation!
Sprint 1: Walking skeleton1. A customer wants cheap vacations2. The customer signs up for daily or weekly notifications of special flight
offers3. Periodically the System checks which customers should get notifications4. The System checks for offers that matches the customer’s travel
preference by looking up flights with the travel provider system5. The System notifies customer of any matching offers via SMS
• Variation: The System notifies customer of any matching offers via email6. The customer accepts the offer via SMS
1. Variation: The customer accepts the offer on the system website7. The System books the tickets on behalf of the customer8. The system confirms the booking by sending an SMS to the customer9. The customer can at any point see their active offers and accepted
offers on the system website10. The customer enjoys a cheap vacation!
Sprint 2: SMS support1. A customer wants cheap vacations2. The customer signs up for daily or weekly notifications of special flight
offers3. Periodically the System checks which customers should get notifications4. The System checks for offers that matches the customer’s travel
preference by looking up flights with the travel provider system5. The System notifies customer of any matching offers via SMS
• Variation: The System notifies customer of any matching offers via email6. The customer accepts the offer via SMS
1. Variation: The customer accepts the offer on the system website7. The System books the tickets on behalf of the customer8. The system confirms the booking by sending an SMS to the customer9. The customer can at any point see their active offers and accepted
offers on the system website10. The customer enjoys a cheap vacation!
Sprint 3: Complete workflow1. A customer wants cheap vacations2. The customer signs up for daily or weekly notifications of special flight
offers3. Periodically the System checks which customers should get notifications4. The System checks for offers that matches the customer’s travel
preference by looking up flights with the travel provider system5. The System notifies customer of any matching offers via SMS
• Variation: The System notifies customer of any matching offers via email6. The customer accepts the offer via SMS
1. Variation: The customer accepts the offer on the system website7. The System books the tickets on behalf of the customer8. The system confirms the booking by sending an SMS to the customer9. The customer can at any point see their active offers and accepted
offers on the system website10. The customer enjoys a cheap vacation!
Sprint 4: Complete SMS1. A customer wants cheap vacations2. The customer signs up for daily or weekly notifications of special flight
offers3. Periodically the System checks which customers should get notifications4. The System checks for offers that matches the customer’s travel
preference by looking up flights with the travel provider system5. The System notifies customer of any matching offers via SMS
• Variation: The System notifies customer of any matching offers via email6. The customer accepts the offer via SMS
1. Variation: The customer accepts the offer on the system website7. The System books the tickets on behalf of the customer8. The system confirms the booking by sending an SMS to the customer9. The customer can at any point see their active offers and accepted
offers on the system website10. The customer enjoys a cheap vacation!
Sprint 5: Web pages1. A customer wants cheap vacations2. The customer signs up for daily or weekly notifications of special flight
offers3. Periodically the System checks which customers should get notifications4. The System checks for offers that matches the customer’s travel
preference by looking up flights with the travel provider system5. The System notifies customer of any matching offers via SMS
• Variation: The System notifies customer of any matching offers via email6. The customer accepts the offer via SMS
1. Variation: The customer accepts the offer on the system website7. The System books the tickets on behalf of the customer8. The system confirms the booking by sending an SMS to the customer9. The customer can at any point see their active offers and accepted
offers on the system website10. The customer enjoys a cheap vacation!
Sprint 7: Integration1. A customer wants cheap vacations2. The customer signs up for daily or weekly notifications of special flight
offers3. Periodically the System checks which customers should get notifications4. The System checks for offers that matches the customer’s travel
preference by looking up flights with the travel provider system5. The System notifies customer of any matching offers via SMS
• Variation: The System notifies customer of any matching offers via email6. The customer accepts the offer via SMS
1. Variation: The customer accepts the offer on the system website7. The System books the tickets on behalf of the customer8. The system confirms the booking by sending an SMS to the customer9. The customer can at any point see their active offers and accepted
offers on the system website10. The customer enjoys a cheap vacation!
Sprint 8: Spit-and-polish1. A customer wants cheap vacations2. The customer signs up for daily or weekly notifications of special flight
offers3. Periodically the System checks which customers should get notifications4. The System checks for offers that matches the customer’s travel
preference by looking up flights with the travel provider system5. The System notifies customer of any matching offers via SMS
• Variation: The System notifies customer of any matching offers via email6. The customer accepts the offer via SMS
1. Variation: The customer accepts the offer on the system website7. The System books the tickets on behalf of the customer8. The system confirms the booking by sending an SMS to the customer9. The customer can at any point see their active offers and accepted
offers on the system website10. The customer enjoys a cheap vacation!
/Delivering software
Conclusion:
Travel light – 7 perspectivesDomain oriented architecture
Sprint with a (rainbow) plan
What’s the common theme?
Usage flow
Good architecture comes from
understanding usage
Thank [email protected]
http://johannesbrodwall.comhttp://exilesoft.com
http://twitter.com/jhannes
• Vision• Stakeholders
• Usage flows – rainbow plans• Context• Domain
• (Simple) Deployment• (Feature oriented) implementation