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
1.8k
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
120
GraphQL Without Hype
szymanskilukasz
0
250
PHP's Not Dead - PHP7 In Practice
szymanskilukasz
10
42k
Text Retrieval
szymanskilukasz
0
160
OLX pod maską [PL]
szymanskilukasz
2
660
Other Decks in Programming
See All in Programming
Scala アプリケーションのビルドを改善してデプロイ時間を 1/4 にした話 | How I improved the build of my Scala application and reduced deployment time by 4x
nomadblacky
1
140
Debugging: All you need to know (for simultaneous interpreting)
jmatsu
2
280
React + TextAliveでカッコいいLyric Applicatioinを作ろう!!
tosuri13
0
380
エンジニア1年目で複雑なコードの改善に取り組んだ話
mtnmr
1
510
Using Livebook to build and deploy internal tools @ ElixirConf 2024
hugobarauna
0
240
初めてのiOS関連GitHub ActionsをMarketplaceに公開するまでの実録
konifar
3
210
Rechartsで楽にゴリゴリにカスタマイズする!
10tera
1
140
Scala におけるコンパイラエラーとの付き合い方
chencmd
2
380
Kotlin 2.0 and Beyond
antonarhipov
2
140
RAGの回答精度評価用のQAデータセットを生成AIに作らせた話
kurahara
0
230
開発を加速する共有Swift Package実践
elmetal
PRO
0
380
Swiftコードバトル必勝法
toshi0383
0
150
Featured
See All Featured
The Art of Programming - Codeland 2020
erikaheidi
48
13k
Teambox: Starting and Learning
jrom
131
8.7k
We Have a Design System, Now What?
morganepeng
48
7.1k
Building Better People: How to give real-time feedback that sticks.
wjessup
359
18k
Web development in the modern age
philhawksworth
204
10k
The MySQL Ecosystem @ GitHub 2015
samlambert
250
12k
I Don’t Have Time: Getting Over the Fear to Launch Your Podcast
jcasabona
26
1.9k
Git: the NoSQL Database
bkeepers
PRO
425
64k
The World Runs on Bad Software
bkeepers
PRO
64
11k
ParisWeb 2013: Learning to Love: Crash Course in Emotional UX Design
dotmariusz
109
6.9k
Creating an realtime collaboration tool: Agile Flush - .NET Oxford
marcduiker
23
1.7k
Fashionably flexible responsive web design (full day workshop)
malarkey
401
65k
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