Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
CQRS & Event Sourcing in OLX
Search
Łukasz Szymański
May 16, 2016
Programming
7
1.9k
CQRS & Event Sourcing in OLX
Łukasz Szymański
May 16, 2016
Tweet
Share
More Decks by Łukasz Szymański
See All by Łukasz Szymański
Chain reaction of scaling up
szymanskilukasz
1
130
GraphQL Without Hype
szymanskilukasz
0
260
PHP's Not Dead - PHP7 In Practice
szymanskilukasz
10
42k
Text Retrieval
szymanskilukasz
0
180
OLX pod maską [PL]
szymanskilukasz
2
700
Other Decks in Programming
See All in Programming
初学者でも今すぐできる、Claude Codeの生産性を10倍上げるTips
s4yuba
16
11k
NPOでのDevinの活用
codeforeveryone
0
830
Hypervel - A Coroutine Framework for Laravel Artisans
albertcht
1
120
AIともっと楽するE2Eテスト
myohei
6
2.6k
Team operations that are not burdened by SRE
kazatohiei
1
310
PicoRuby on Rails
makicamel
2
130
「テストは愚直&&網羅的に書くほどよい」という誤解 / Test Smarter, Not Harder
munetoshi
0
170
Blazing Fast UI Development with Compose Hot Reload (droidcon New York 2025)
zsmb
1
290
今ならAmazon ECSのサービス間通信をどう選ぶか / Selection of ECS Interservice Communication 2025
tkikuc
21
4k
ペアプロ × 生成AI 現場での実践と課題について / generative-ai-in-pair-programming
codmoninc
1
18k
地方に住むエンジニアの残酷な現実とキャリア論
ichimichi
5
1.5k
PHPで始める振る舞い駆動開発(Behaviour-Driven Development)
ohmori_yusuke
2
390
Featured
See All Featured
Side Projects
sachag
455
42k
Optimising Largest Contentful Paint
csswizardry
37
3.3k
Fashionably flexible responsive web design (full day workshop)
malarkey
407
66k
How to Think Like a Performance Engineer
csswizardry
25
1.7k
Refactoring Trust on Your Teams (GOTO; Chicago 2020)
rmw
34
3.1k
How to Ace a Technical Interview
jacobian
278
23k
What’s in a name? Adding method to the madness
productmarketing
PRO
23
3.5k
A Tale of Four Properties
chriscoyier
160
23k
A better future with KSS
kneath
238
17k
KATA
mclloyd
30
14k
Six Lessons from altMBA
skipperchong
28
3.9k
Practical Tips for Bootstrapping Information Extraction Pipelines
honnibal
PRO
20
1.3k
Transcript
CQRS Event Sourcing in OLX
CQRS
you can use a different model to update information than
the model you use to read information http://martinfowler.com/bliki/CQRS.html „
Command Query Responsibility Segregation
Command Query Responsibility Segregation
new AddCredits($userId, $amount); Command
Command new AddCredits($userId, $amount); Query new GetCredits($userId);
Event Sourcing
http://www.martinfowler.com/eaaDev/EventSourcing.html „ ensures that all changes to application state are
stored as a sequence of events
Not just can we query these events, we can also
use the event log to reconstruct past states http://www.martinfowler.com/eaaDev/EventSourcing.html „
Commad Event Model Event Storage Event Bus Command Handler Listeners
Read Storage Read Model Query
Commad Event Model Event Storage Event Bus Command Handler Listeners
Read Storage Read Model Query Critical section - use transaction
Commad Event Model Event Storage Event Bus Command Handler Listeners
Read Storage Read Model Query Critical section - use transaction Treat like temporary cache
That’s all
E-Wallet Credits; Invoices; Refunds
Wallet Credits Bonus Credits Refund Credits EXPIRE: X DAYS EXPIRE:
X DAYS EXPIRE: X DAYS INVOICE: YES/NO INVOICE: YES/NO INVOICE: YES/NO
Wallet Credits Bonus Credits Refund Credits EXPIRE: NEVER EXPIRE: 90
DAYS EXPIRE: 90 DAYS INVOICE: YES INVOICE: NO INVOICE: YES
Opis walleta w Polsce specyfikacja komenty enventy Commands
Add Wallet Credits Add Bonus Credits Add Refund Credits
Sub Wallet Credits Sub Bonus Credits Sub Refund Credits SubCredits
Opis walleta w Polsce specyfikacja komenty enventy Events
Wallet CreditsWasAdded Bonus CreditsWasAdded Refund CreditsWasAdded
Wallet CreditsWasSubtracted Bonus CreditsWasSubtracted Refund CreditsWasSubtracted
specyfikacja komenty enventy 7 commands 6 events
specyfikacja komenty enventy What about other stuff?
Commad Event Model Event Storage Event Bus Command Handler Listeners
Read Storage Read Model Query ?
Broadway komponenty Broadway https://github.com/qandidate-labs/broadway
Auditing log whether commands were successful or not
CommandHandling Provides the interface and a CommandHandler base class for
handling events
Domain domain abstractions of the Broadway framework including the aggregate
root, domain messages and domain events.
EventDispatcher The component provides an event dispatcher interface and a
simple implementation
EventHandling provides interfaces for an event bus and event listeners,
but also an implementation of a simple event bus and an event bus that will record published events
EventSourcing Provides base classes for event sourced aggregate roots and
entities, an event sourced repository implementation and testing helpers.
EventStore implementation based on doctrine/dbal to store events in a
relational database and an in-memory implementation that is useful for using in tests
ReadModel provides storage for your read models, a projector implementation
to create read models from event streams and testing helpers.
Repository Component providing an abstraction of the storage of aggregates.
Serializers provides a simple serializer interface and a serializer implementation
based on "handwritten" serializers
Commad Event Model Event Storage Event Bus Command Handler Listeners
Read Storage Read Model Query Broadway
Adding Wallet Credits
None
None
Credits Query
None
None
Lessons Learned
Small Steps Don’t try to CQRS/EventSource everything
Keep It Simple Avoid names like BonusCreditsWasSubtractedBecauseAdminHitSubtractBonusCr editsInAdminPanelEvent
Event Storming is not that easy as it sounds
It’s not RDBM Remember about analysts
Code changes Events handle changes to data, what about changes
to code?
Synchronize Remember about synchronizing read layer - especially after fail
Commad Event Model Event Storage Event Bus Command Handler Listeners
Read Storage Read Model Query Critical section - use transaction
Performance is not an issue - for this case
Timezone Agnostic Implement your own EventStore if you want timezone
aware records
Our Team
Paid Features
Next challenge Open source Paid Features libraries with Hexagonal Architecture
in mind
Team Lead PHP Dev Junior PHP Dev You ?
Łukasz Szymański Development Team Lead at @szymanskilukasz http://szymanskilukasz.github.io/ https://www.linkedin.com/in/szymanskilukasz https://twitter.com/szymanskilukasz