SlideShare a Scribd company logo
1 of 41
Download to read offline
A visual introduction to

Event Sourcing and CQRS
1
@nicusX
https://opencredo.com/author/lorenzo/
Lorenzo Nicora
Senior Consultant @ OpenCredo
2
A couple of concepts from DDD
Aggregate
(Current) State

of the Aggregate
Lorenzo Nicora Intro to Event Sourcing and CQRS
3
Once upon a time…
Everything
is synchronous
Request - Response
Lorenzo Nicora Intro to Event Sourcing and CQRS
4
Scaling up…
Updates —> Locks —> Contention!
<— Block <—
Lorenzo Nicora Intro to Event Sourcing and CQRS
5
Let’s go Asynchronous
Pwd —> “secret”
Pwd —> “12345”
Pwd —> “54321”
Pwd —> “secret”
Pwd —> “54321”
Pwd —> “12345”
===>

Out of 

Order
Asynchronous, Message-driven
Request/Response
ACID Transaction
Distributed, Message-based 

—> No order guaranteed
Lorenzo Nicora Intro to Event Sourcing and CQRS
6
Command Sourcing
💡
• Append Only —> No Contention
• Build State from Command history
Write fast,
Think later
K/V Store
Distributed
Lorenzo Nicora Intro to Event Sourcing and CQRS
Command
“Submit Order!”
—> A request (imperative sentence)
—> May fail
—> May affect multiple Aggregates
7
Commands vs Events
✉
Rebuild Aggregate State 

from Commands
Lorenzo Nicora Intro to Event Sourcing and CQRS
8
Event
“Order submitted”
—> Statement of facts (past tense)
—> Never fails
—> May affect a single Aggregate
✉
Rebuild Aggregate State 

from Events
Lorenzo Nicora Intro to Event Sourcing and CQRS
9
Commands to Events
(DDD patterns: Aggregate / Process Manager)
X
Y
Z
Lorenzo Nicora Intro to Event Sourcing and CQRS
10
Command > Event Sourcing
💡
Think a little,
Write,
Think later
Lorenzo Nicora Intro to Event Sourcing and CQRS
11
Event Sourcing
In many domains
Commands Events
Lorenzo Nicora Intro to Event Sourcing and CQRS
12
Additional Benefits
Easy

Eventual Business Consistency
—> Corrective Events
Robust to data corruption
(bugs, fat fingers…)
—> Rebuild state ignoring wrong events
Lorenzo Nicora Intro to Event Sourcing and CQRS
13
Additional Benefits
History
(for free)
Rebuild State 

at a point in Time
Lorenzo Nicora Intro to Event Sourcing and CQRS
14
Main Benefit
Scalable
—> Append only
-> Fits distributed k/v stores
—> Low-latency writes
—> Allows asynchronous processing
Lorenzo Nicora Intro to Event Sourcing and CQRS
What about reads?
15
Lorenzo Nicora Intro to Event Sourcing and CQRS
16
Retrieving the State
How do I retrieve the State?
“Get details of Order ‘AB123’”
❔
not very efficient, but…
…may work
Lorenzo Nicora Intro to Event Sourcing and CQRS
17
Querying (Searching) the State
❓
❓ How do query the State?
“Get all Orders delivered to ‘SE1 0NZ’”
❓
❓
Lorenzo Nicora Intro to Event Sourcing and CQRS
18
CQRS
Command
Query
Responsibility
Segregation
💡 Separate
• Code
• muService
• Datastore
-> Update
-—> Retrieve
“Query”
datastore is
downstream
Lorenzo Nicora Intro to Event Sourcing and CQRS
19
Not a new idea
Specialised
Downstream
Lorenzo Nicora Intro to Event Sourcing and CQRS
20
CQRS and Event Sourcing
Lorenzo Nicora Intro to Event Sourcing and CQRS
21
Materialised Views 

(of current State)
Lorenzo Nicora Intro to Event Sourcing and CQRS
22
Materialised Views (of State)
Latest (known) State
(Persistent)

Rebuildable
from Events
In Memory

K/V Store
Graph
…
RDBMS
Delayed
💡
Lorenzo Nicora Intro to Event Sourcing and CQRS
23
Materialised View of State
Query a RDBMS?!?
Wasn’t it the old way?
❓
RDBMS is just one of our options:

easy to use, easily become a bottleneck
Lorenzo Nicora Intro to Event Sourcing and CQRS
24
Materialised Views of State
* Views are optimised for 

specific query use cases
—> multiple Views from same Events
* Updated asynchronously, delayed
—> to Scale
-> may reorder Events
Lorenzo Nicora Intro to Event Sourcing and CQRS
25
Materialised Views of State
* Views can be rebuilt from Events
Event Log
is our Source of Truth
* Easy to evolve or fix
—> change or fix logic;
rebuild view from events
(not the View)
Lorenzo Nicora Intro to Event Sourcing and CQRS
26
Indexes
Lorenzo Nicora Intro to Event Sourcing and CQRS
27
Indexes
Search Engines

K/V Stores
• Optimised for querying (less for retrieving)
• Latest State; rebuild on the fly
💡
Lorenzo Nicora Intro to Event Sourcing and CQRS
28
Hybrid solutions
Lorenzo Nicora Intro to Event Sourcing and CQRS
29
Hybrid solutions: e.g. Snapshots
• Speed up rebuilding the current State
• Use recent Events to rebuild up-to-date
💡 Long delayed
Lorenzo Nicora Intro to Event Sourcing and CQRS
30
Eventual (Business) Consistency
Guess —> Compensate—> Apologies
Lorenzo Nicora Intro to Event Sourcing and CQRS
31
Eventual Consistency: Sagas
StatefulOut of band
Corrective Command 

or Event
Saga
Lorenzo Nicora Intro to Event Sourcing and CQRS
32
Lesson

from the Trenches
Lorenzo Nicora Intro to Event Sourcing and CQRS
33
Lesson Learned #1
If you put data in…
…you will eventually

have to get them out!
The “Query” side 

is not secondary
Lorenzo Nicora Intro to Event Sourcing and CQRS
34
Lessons Learned #2
In old days:

normalising one DB 

to support as many queries as possible
With CQRS: 

multiple denormalised “data stores”

optimised for different queries
No single “Q” implementation 

for all your queries
Lorenzo Nicora Intro to Event Sourcing and CQRS
35
Lessons Learned #3
A central, shared Event Store

may not be the best option
No Event-sourced Monolith
Prefer persistence 

per Bounded-Context
Lorenzo Nicora Intro to Event Sourcing and CQRS
+++ Summing up +++
36
Lorenzo Nicora Intro to Event Sourcing and CQRS
37
ES/CQRS Optimal Use Cases
High Volume
Low Latency writes
(big data)
Event Sourcing + CQRS
😋
Out-of-order Commands/Events

(IoT)
Lorenzo Nicora Intro to Event Sourcing and CQRS
38
ES/CQRS Drawbacks
x No “One-Size-Fits-All”

—> Multiple “Q” implementations
x Delayed reads
x No ACID Transactions
x Additional complexity (!)
🙁
Lorenzo Nicora Intro to Event Sourcing and CQRS
39
ES/CQRS Benefits
+ No “One-Size-Fits-All”
—> “Q” are optimised for use cases
+ Eventual (Business) Consistency
+ History, Temporal queries
+ Robust to data corruption
😀
Lorenzo Nicora Intro to Event Sourcing and CQRS
That’s all, Folks!
40
Lorenzo Nicora Intro to Event Sourcing and CQRS
??? Questions ???
41
Thanks.
⏳
Lorenzo Nicora Intro to Event Sourcing and CQRS

More Related Content

What's hot

From my sql to postgresql using kafka+debezium
From my sql to postgresql using kafka+debeziumFrom my sql to postgresql using kafka+debezium
From my sql to postgresql using kafka+debeziumClement Demonchy
 
Grokking TechTalk #33: High Concurrency Architecture at TIKI
Grokking TechTalk #33: High Concurrency Architecture at TIKIGrokking TechTalk #33: High Concurrency Architecture at TIKI
Grokking TechTalk #33: High Concurrency Architecture at TIKIGrokking VN
 
Micro services Architecture
Micro services ArchitectureMicro services Architecture
Micro services ArchitectureAraf Karsh Hamid
 
Microservices Architecture & Testing Strategies
Microservices Architecture & Testing StrategiesMicroservices Architecture & Testing Strategies
Microservices Architecture & Testing StrategiesAraf Karsh Hamid
 
CQRS and Event Sourcing
CQRS and Event Sourcing CQRS and Event Sourcing
CQRS and Event Sourcing Inho Kang
 
[오픈소스컨설팅]Day #1 MySQL 엔진소개, 튜닝, 백업 및 복구, 업그레이드방법
[오픈소스컨설팅]Day #1 MySQL 엔진소개, 튜닝, 백업 및 복구, 업그레이드방법[오픈소스컨설팅]Day #1 MySQL 엔진소개, 튜닝, 백업 및 복구, 업그레이드방법
[오픈소스컨설팅]Day #1 MySQL 엔진소개, 튜닝, 백업 및 복구, 업그레이드방법Ji-Woong Choi
 
Microservices Architecture - Bangkok 2018
Microservices Architecture - Bangkok 2018Microservices Architecture - Bangkok 2018
Microservices Architecture - Bangkok 2018Araf Karsh Hamid
 
MongoDB vs. Postgres Benchmarks
MongoDB vs. Postgres Benchmarks MongoDB vs. Postgres Benchmarks
MongoDB vs. Postgres Benchmarks EDB
 
CQRS and Event Sourcing for Java Developers
CQRS and Event Sourcing for Java DevelopersCQRS and Event Sourcing for Java Developers
CQRS and Event Sourcing for Java DevelopersMarkus Eisele
 
Event-driven microservices
Event-driven microservicesEvent-driven microservices
Event-driven microservicesAndrew Schofield
 
[오픈소스컨설팅] 서비스 메쉬(Service mesh)
[오픈소스컨설팅] 서비스 메쉬(Service mesh)[오픈소스컨설팅] 서비스 메쉬(Service mesh)
[오픈소스컨설팅] 서비스 메쉬(Service mesh)Open Source Consulting
 
Comparison of Current Service Mesh Architectures
Comparison of Current Service Mesh ArchitecturesComparison of Current Service Mesh Architectures
Comparison of Current Service Mesh ArchitecturesMirantis
 
Scaling Redis To 1M Ops/Sec: Jane Paek
Scaling Redis To 1M Ops/Sec: Jane PaekScaling Redis To 1M Ops/Sec: Jane Paek
Scaling Redis To 1M Ops/Sec: Jane PaekRedis Labs
 
Service Mesh - Observability
Service Mesh - ObservabilityService Mesh - Observability
Service Mesh - ObservabilityAraf Karsh Hamid
 
CockroachDB: Architecture of a Geo-Distributed SQL Database
CockroachDB: Architecture of a Geo-Distributed SQL DatabaseCockroachDB: Architecture of a Geo-Distributed SQL Database
CockroachDB: Architecture of a Geo-Distributed SQL DatabaseC4Media
 
ProxySQL High Avalability and Configuration Management Overview
ProxySQL High Avalability and Configuration Management OverviewProxySQL High Avalability and Configuration Management Overview
ProxySQL High Avalability and Configuration Management OverviewRené Cannaò
 

What's hot (20)

From my sql to postgresql using kafka+debezium
From my sql to postgresql using kafka+debeziumFrom my sql to postgresql using kafka+debezium
From my sql to postgresql using kafka+debezium
 
Grokking TechTalk #33: High Concurrency Architecture at TIKI
Grokking TechTalk #33: High Concurrency Architecture at TIKIGrokking TechTalk #33: High Concurrency Architecture at TIKI
Grokking TechTalk #33: High Concurrency Architecture at TIKI
 
Micro services Architecture
Micro services ArchitectureMicro services Architecture
Micro services Architecture
 
Microservices Architecture & Testing Strategies
Microservices Architecture & Testing StrategiesMicroservices Architecture & Testing Strategies
Microservices Architecture & Testing Strategies
 
An introduction to MongoDB
An introduction to MongoDBAn introduction to MongoDB
An introduction to MongoDB
 
CQRS and Event Sourcing
CQRS and Event Sourcing CQRS and Event Sourcing
CQRS and Event Sourcing
 
Patterns of resilience
Patterns of resiliencePatterns of resilience
Patterns of resilience
 
[오픈소스컨설팅]Day #1 MySQL 엔진소개, 튜닝, 백업 및 복구, 업그레이드방법
[오픈소스컨설팅]Day #1 MySQL 엔진소개, 튜닝, 백업 및 복구, 업그레이드방법[오픈소스컨설팅]Day #1 MySQL 엔진소개, 튜닝, 백업 및 복구, 업그레이드방법
[오픈소스컨설팅]Day #1 MySQL 엔진소개, 튜닝, 백업 및 복구, 업그레이드방법
 
Microservices Architecture - Bangkok 2018
Microservices Architecture - Bangkok 2018Microservices Architecture - Bangkok 2018
Microservices Architecture - Bangkok 2018
 
MongoDB vs. Postgres Benchmarks
MongoDB vs. Postgres Benchmarks MongoDB vs. Postgres Benchmarks
MongoDB vs. Postgres Benchmarks
 
CQRS and Event Sourcing for Java Developers
CQRS and Event Sourcing for Java DevelopersCQRS and Event Sourcing for Java Developers
CQRS and Event Sourcing for Java Developers
 
Event-driven microservices
Event-driven microservicesEvent-driven microservices
Event-driven microservices
 
[오픈소스컨설팅] 서비스 메쉬(Service mesh)
[오픈소스컨설팅] 서비스 메쉬(Service mesh)[오픈소스컨설팅] 서비스 메쉬(Service mesh)
[오픈소스컨설팅] 서비스 메쉬(Service mesh)
 
Introduction to Microservices
Introduction to MicroservicesIntroduction to Microservices
Introduction to Microservices
 
Comparison of Current Service Mesh Architectures
Comparison of Current Service Mesh ArchitecturesComparison of Current Service Mesh Architectures
Comparison of Current Service Mesh Architectures
 
Scaling Redis To 1M Ops/Sec: Jane Paek
Scaling Redis To 1M Ops/Sec: Jane PaekScaling Redis To 1M Ops/Sec: Jane Paek
Scaling Redis To 1M Ops/Sec: Jane Paek
 
Introduction to Microservices
Introduction to MicroservicesIntroduction to Microservices
Introduction to Microservices
 
Service Mesh - Observability
Service Mesh - ObservabilityService Mesh - Observability
Service Mesh - Observability
 
CockroachDB: Architecture of a Geo-Distributed SQL Database
CockroachDB: Architecture of a Geo-Distributed SQL DatabaseCockroachDB: Architecture of a Geo-Distributed SQL Database
CockroachDB: Architecture of a Geo-Distributed SQL Database
 
ProxySQL High Avalability and Configuration Management Overview
ProxySQL High Avalability and Configuration Management OverviewProxySQL High Avalability and Configuration Management Overview
ProxySQL High Avalability and Configuration Management Overview
 

Viewers also liked

Developing event-driven microservices with event sourcing and CQRS (phillyete)
Developing event-driven microservices with event sourcing and CQRS (phillyete)Developing event-driven microservices with event sourcing and CQRS (phillyete)
Developing event-driven microservices with event sourcing and CQRS (phillyete)Chris Richardson
 
Microservice Architecture with CQRS and Event Sourcing
Microservice Architecture with CQRS and Event SourcingMicroservice Architecture with CQRS and Event Sourcing
Microservice Architecture with CQRS and Event SourcingBen Wilcock
 
Haufe #msaday - Building a Microservice Ecosystem by Daniel Bryant
Haufe #msaday - Building a Microservice Ecosystem by Daniel Bryant Haufe #msaday - Building a Microservice Ecosystem by Daniel Bryant
Haufe #msaday - Building a Microservice Ecosystem by Daniel Bryant OpenCredo
 
Voxxed Bristol 2017 - From C to Q, one event at a time: Event Sourcing illust...
Voxxed Bristol 2017 - From C to Q, one event at a time: Event Sourcing illust...Voxxed Bristol 2017 - From C to Q, one event at a time: Event Sourcing illust...
Voxxed Bristol 2017 - From C to Q, one event at a time: Event Sourcing illust...OpenCredo
 
Reactive Microservices By Lorenzo Nicora
Reactive Microservices By Lorenzo NicoraReactive Microservices By Lorenzo Nicora
Reactive Microservices By Lorenzo NicoraOpenCredo
 
QCON London 2017 - Monitoring Serverless Architectures by Rafal Gancarz
QCON London 2017 - Monitoring Serverless Architectures by Rafal GancarzQCON London 2017 - Monitoring Serverless Architectures by Rafal Gancarz
QCON London 2017 - Monitoring Serverless Architectures by Rafal GancarzOpenCredo
 
Developing event-driven microservices with event sourcing and CQRS (svcc, sv...
Developing event-driven microservices with event sourcing and CQRS  (svcc, sv...Developing event-driven microservices with event sourcing and CQRS  (svcc, sv...
Developing event-driven microservices with event sourcing and CQRS (svcc, sv...Chris Richardson
 
GOTO LONDON 2016: Concursus Event sourcing Evolved (Updated)
GOTO LONDON 2016: Concursus Event sourcing Evolved (Updated)GOTO LONDON 2016: Concursus Event sourcing Evolved (Updated)
GOTO LONDON 2016: Concursus Event sourcing Evolved (Updated)OpenCredo
 
Haufe #msaday - Seven More Deadly Sins of Microservices by Daniel Bryant
Haufe #msaday - Seven More Deadly Sins of Microservices by Daniel Bryant Haufe #msaday - Seven More Deadly Sins of Microservices by Daniel Bryant
Haufe #msaday - Seven More Deadly Sins of Microservices by Daniel Bryant OpenCredo
 
Evolving Project Management: from the sin to the virtue by Antonio Cobo
Evolving Project Management: from the sin to the virtue by Antonio CoboEvolving Project Management: from the sin to the virtue by Antonio Cobo
Evolving Project Management: from the sin to the virtue by Antonio CoboOpenCredo
 
ServerlessConf: Serverless for the Enterprise - Rafal Gancarz
ServerlessConf: Serverless for the Enterprise - Rafal GancarzServerlessConf: Serverless for the Enterprise - Rafal Gancarz
ServerlessConf: Serverless for the Enterprise - Rafal GancarzOpenCredo
 
O'Reilly 2016: "Continuous Delivery with Containers: The Trials and Tribulati...
O'Reilly 2016: "Continuous Delivery with Containers: The Trials and Tribulati...O'Reilly 2016: "Continuous Delivery with Containers: The Trials and Tribulati...
O'Reilly 2016: "Continuous Delivery with Containers: The Trials and Tribulati...OpenCredo
 
High Load Strategy 2016 - Project Management: from Stone Age to DevOps
High Load Strategy 2016 - Project Management: from Stone Age to DevOps High Load Strategy 2016 - Project Management: from Stone Age to DevOps
High Load Strategy 2016 - Project Management: from Stone Age to DevOps OpenCredo
 
A year with event sourcing and CQRS
A year with event sourcing and CQRSA year with event sourcing and CQRS
A year with event sourcing and CQRSSteve Pember
 
muCon 2016: Authentication in Microservice Systems By David Borsos
muCon 2016: Authentication in Microservice Systems By David BorsosmuCon 2016: Authentication in Microservice Systems By David Borsos
muCon 2016: Authentication in Microservice Systems By David BorsosOpenCredo
 
CQRS and Event Sourcing, An Alternative Architecture for DDD
CQRS and Event Sourcing, An Alternative Architecture for DDDCQRS and Event Sourcing, An Alternative Architecture for DDD
CQRS and Event Sourcing, An Alternative Architecture for DDDDennis Doomen
 
London Hashicorp Meetup #8 - Testing Programmable Infrastructure By Matt Long
London Hashicorp Meetup #8 -  Testing Programmable Infrastructure By Matt LongLondon Hashicorp Meetup #8 -  Testing Programmable Infrastructure By Matt Long
London Hashicorp Meetup #8 - Testing Programmable Infrastructure By Matt LongOpenCredo
 
Haufe #msaday - The Actor model: an alternative approach to concurrency By Lo...
Haufe #msaday - The Actor model: an alternative approach to concurrency By Lo...Haufe #msaday - The Actor model: an alternative approach to concurrency By Lo...
Haufe #msaday - The Actor model: an alternative approach to concurrency By Lo...OpenCredo
 

Viewers also liked (20)

Developing event-driven microservices with event sourcing and CQRS (phillyete)
Developing event-driven microservices with event sourcing and CQRS (phillyete)Developing event-driven microservices with event sourcing and CQRS (phillyete)
Developing event-driven microservices with event sourcing and CQRS (phillyete)
 
Microservice Architecture with CQRS and Event Sourcing
Microservice Architecture with CQRS and Event SourcingMicroservice Architecture with CQRS and Event Sourcing
Microservice Architecture with CQRS and Event Sourcing
 
Haufe #msaday - Building a Microservice Ecosystem by Daniel Bryant
Haufe #msaday - Building a Microservice Ecosystem by Daniel Bryant Haufe #msaday - Building a Microservice Ecosystem by Daniel Bryant
Haufe #msaday - Building a Microservice Ecosystem by Daniel Bryant
 
Voxxed Bristol 2017 - From C to Q, one event at a time: Event Sourcing illust...
Voxxed Bristol 2017 - From C to Q, one event at a time: Event Sourcing illust...Voxxed Bristol 2017 - From C to Q, one event at a time: Event Sourcing illust...
Voxxed Bristol 2017 - From C to Q, one event at a time: Event Sourcing illust...
 
Reactive Microservices By Lorenzo Nicora
Reactive Microservices By Lorenzo NicoraReactive Microservices By Lorenzo Nicora
Reactive Microservices By Lorenzo Nicora
 
QCON London 2017 - Monitoring Serverless Architectures by Rafal Gancarz
QCON London 2017 - Monitoring Serverless Architectures by Rafal GancarzQCON London 2017 - Monitoring Serverless Architectures by Rafal Gancarz
QCON London 2017 - Monitoring Serverless Architectures by Rafal Gancarz
 
Developing event-driven microservices with event sourcing and CQRS (svcc, sv...
Developing event-driven microservices with event sourcing and CQRS  (svcc, sv...Developing event-driven microservices with event sourcing and CQRS  (svcc, sv...
Developing event-driven microservices with event sourcing and CQRS (svcc, sv...
 
GOTO LONDON 2016: Concursus Event sourcing Evolved (Updated)
GOTO LONDON 2016: Concursus Event sourcing Evolved (Updated)GOTO LONDON 2016: Concursus Event sourcing Evolved (Updated)
GOTO LONDON 2016: Concursus Event sourcing Evolved (Updated)
 
Haufe #msaday - Seven More Deadly Sins of Microservices by Daniel Bryant
Haufe #msaday - Seven More Deadly Sins of Microservices by Daniel Bryant Haufe #msaday - Seven More Deadly Sins of Microservices by Daniel Bryant
Haufe #msaday - Seven More Deadly Sins of Microservices by Daniel Bryant
 
Evolving Project Management: from the sin to the virtue by Antonio Cobo
Evolving Project Management: from the sin to the virtue by Antonio CoboEvolving Project Management: from the sin to the virtue by Antonio Cobo
Evolving Project Management: from the sin to the virtue by Antonio Cobo
 
ServerlessConf: Serverless for the Enterprise - Rafal Gancarz
ServerlessConf: Serverless for the Enterprise - Rafal GancarzServerlessConf: Serverless for the Enterprise - Rafal Gancarz
ServerlessConf: Serverless for the Enterprise - Rafal Gancarz
 
O'Reilly 2016: "Continuous Delivery with Containers: The Trials and Tribulati...
O'Reilly 2016: "Continuous Delivery with Containers: The Trials and Tribulati...O'Reilly 2016: "Continuous Delivery with Containers: The Trials and Tribulati...
O'Reilly 2016: "Continuous Delivery with Containers: The Trials and Tribulati...
 
High Load Strategy 2016 - Project Management: from Stone Age to DevOps
High Load Strategy 2016 - Project Management: from Stone Age to DevOps High Load Strategy 2016 - Project Management: from Stone Age to DevOps
High Load Strategy 2016 - Project Management: from Stone Age to DevOps
 
A year with event sourcing and CQRS
A year with event sourcing and CQRSA year with event sourcing and CQRS
A year with event sourcing and CQRS
 
muCon 2016: Authentication in Microservice Systems By David Borsos
muCon 2016: Authentication in Microservice Systems By David BorsosmuCon 2016: Authentication in Microservice Systems By David Borsos
muCon 2016: Authentication in Microservice Systems By David Borsos
 
CQRS and Event Sourcing, An Alternative Architecture for DDD
CQRS and Event Sourcing, An Alternative Architecture for DDDCQRS and Event Sourcing, An Alternative Architecture for DDD
CQRS and Event Sourcing, An Alternative Architecture for DDD
 
Event-sourced architectures with Akka
Event-sourced architectures with AkkaEvent-sourced architectures with Akka
Event-sourced architectures with Akka
 
London Hashicorp Meetup #8 - Testing Programmable Infrastructure By Matt Long
London Hashicorp Meetup #8 -  Testing Programmable Infrastructure By Matt LongLondon Hashicorp Meetup #8 -  Testing Programmable Infrastructure By Matt Long
London Hashicorp Meetup #8 - Testing Programmable Infrastructure By Matt Long
 
Haufe #msaday - The Actor model: an alternative approach to concurrency By Lo...
Haufe #msaday - The Actor model: an alternative approach to concurrency By Lo...Haufe #msaday - The Actor model: an alternative approach to concurrency By Lo...
Haufe #msaday - The Actor model: an alternative approach to concurrency By Lo...
 
CQRS
CQRSCQRS
CQRS
 

Similar to Visual Intro to Event Sourcing and CQRS

From C to Q, one event at the time: Event sourcing illustrated [Voxxed Ticino...
From C to Q, one event at the time: Event sourcing illustrated [Voxxed Ticino...From C to Q, one event at the time: Event sourcing illustrated [Voxxed Ticino...
From C to Q, one event at the time: Event sourcing illustrated [Voxxed Ticino...Lorenzo Nicora
 
Event sourcing for IoT and mobile - JAX London 2017
Event sourcing for IoT and mobile - JAX London 2017Event sourcing for IoT and mobile - JAX London 2017
Event sourcing for IoT and mobile - JAX London 2017Lorenzo Nicora
 
From C to Q one event at a time: Event Sourcing illustrated
From C to Q one event at a time: Event Sourcing illustratedFrom C to Q one event at a time: Event Sourcing illustrated
From C to Q one event at a time: Event Sourcing illustratedLorenzo Nicora
 
How Fast Data Is Turned into Fast Information and Timely Action (OOW 2014)
How Fast Data Is Turned into Fast Information and Timely Action (OOW 2014)How Fast Data Is Turned into Fast Information and Timely Action (OOW 2014)
How Fast Data Is Turned into Fast Information and Timely Action (OOW 2014)Lucas Jellema
 
Introduction to ksqlDB and stream processing (Vish Srinivasan - Confluent)
Introduction to ksqlDB and stream processing (Vish Srinivasan  - Confluent)Introduction to ksqlDB and stream processing (Vish Srinivasan  - Confluent)
Introduction to ksqlDB and stream processing (Vish Srinivasan - Confluent)KafkaZone
 
Stream processing with Apache Flink - Maximilian Michels Data Artisans
Stream processing with Apache Flink - Maximilian Michels Data ArtisansStream processing with Apache Flink - Maximilian Michels Data Artisans
Stream processing with Apache Flink - Maximilian Michels Data ArtisansEvention
 
Sync or swim: the challenge of complex offline apps
Sync or swim:  the challenge of complex offline appsSync or swim:  the challenge of complex offline apps
Sync or swim: the challenge of complex offline appsOutSystems
 

Similar to Visual Intro to Event Sourcing and CQRS (9)

From C to Q, one event at the time: Event sourcing illustrated [Voxxed Ticino...
From C to Q, one event at the time: Event sourcing illustrated [Voxxed Ticino...From C to Q, one event at the time: Event sourcing illustrated [Voxxed Ticino...
From C to Q, one event at the time: Event sourcing illustrated [Voxxed Ticino...
 
Event sourcing for IoT and mobile - JAX London 2017
Event sourcing for IoT and mobile - JAX London 2017Event sourcing for IoT and mobile - JAX London 2017
Event sourcing for IoT and mobile - JAX London 2017
 
From C to Q one event at a time: Event Sourcing illustrated
From C to Q one event at a time: Event Sourcing illustratedFrom C to Q one event at a time: Event Sourcing illustrated
From C to Q one event at a time: Event Sourcing illustrated
 
How Fast Data Is Turned into Fast Information and Timely Action (OOW 2014)
How Fast Data Is Turned into Fast Information and Timely Action (OOW 2014)How Fast Data Is Turned into Fast Information and Timely Action (OOW 2014)
How Fast Data Is Turned into Fast Information and Timely Action (OOW 2014)
 
Introduction to ksqlDB and stream processing (Vish Srinivasan - Confluent)
Introduction to ksqlDB and stream processing (Vish Srinivasan  - Confluent)Introduction to ksqlDB and stream processing (Vish Srinivasan  - Confluent)
Introduction to ksqlDB and stream processing (Vish Srinivasan - Confluent)
 
Stream processing with Apache Flink - Maximilian Michels Data Artisans
Stream processing with Apache Flink - Maximilian Michels Data ArtisansStream processing with Apache Flink - Maximilian Michels Data Artisans
Stream processing with Apache Flink - Maximilian Michels Data Artisans
 
Big Data Warsaw
Big Data WarsawBig Data Warsaw
Big Data Warsaw
 
Sync or swim: the challenge of complex offline apps
Sync or swim:  the challenge of complex offline appsSync or swim:  the challenge of complex offline apps
Sync or swim: the challenge of complex offline apps
 
How fast data is turned into fast information and timely action - Oracle Open...
How fast data is turned into fast information and timely action - Oracle Open...How fast data is turned into fast information and timely action - Oracle Open...
How fast data is turned into fast information and timely action - Oracle Open...
 

More from OpenCredo

Webinar - Design Thinking for Platform Engineering
Webinar - Design Thinking for Platform EngineeringWebinar - Design Thinking for Platform Engineering
Webinar - Design Thinking for Platform EngineeringOpenCredo
 
MuCon 2019: Exploring Your Microservices Architecture Through Network Science...
MuCon 2019: Exploring Your Microservices Architecture Through Network Science...MuCon 2019: Exploring Your Microservices Architecture Through Network Science...
MuCon 2019: Exploring Your Microservices Architecture Through Network Science...OpenCredo
 
Goto Chicago; Journeys To Cloud Native Architecture: Sun, Sea And Emergencies...
Goto Chicago; Journeys To Cloud Native Architecture: Sun, Sea And Emergencies...Goto Chicago; Journeys To Cloud Native Architecture: Sun, Sea And Emergencies...
Goto Chicago; Journeys To Cloud Native Architecture: Sun, Sea And Emergencies...OpenCredo
 
Mucon 2018: Heuristics for Identifying Microservice Boundaries By Erich Eichi...
Mucon 2018: Heuristics for Identifying Microservice Boundaries By Erich Eichi...Mucon 2018: Heuristics for Identifying Microservice Boundaries By Erich Eichi...
Mucon 2018: Heuristics for Identifying Microservice Boundaries By Erich Eichi...OpenCredo
 
Journeys To Cloud Native Architecture: Sun, Sea And Emergencies - Nicki Watt
Journeys To Cloud Native Architecture: Sun, Sea And Emergencies - Nicki WattJourneys To Cloud Native Architecture: Sun, Sea And Emergencies - Nicki Watt
Journeys To Cloud Native Architecture: Sun, Sea And Emergencies - Nicki WattOpenCredo
 
Machine Learning Game Changer for IT - Maartens Lourens
Machine Learning Game Changer for IT - Maartens LourensMachine Learning Game Changer for IT - Maartens Lourens
Machine Learning Game Changer for IT - Maartens LourensOpenCredo
 
Kafka Summit 2018: A Journey Building Kafka Connectors - Pegerto Fernandez
Kafka Summit 2018: A Journey Building Kafka Connectors - Pegerto FernandezKafka Summit 2018: A Journey Building Kafka Connectors - Pegerto Fernandez
Kafka Summit 2018: A Journey Building Kafka Connectors - Pegerto FernandezOpenCredo
 
MuCon 2017: A not So(A) Trivial Question by Tareq Abedrabbo
MuCon 2017: A not So(A) Trivial Question by Tareq AbedrabboMuCon 2017: A not So(A) Trivial Question by Tareq Abedrabbo
MuCon 2017: A not So(A) Trivial Question by Tareq AbedrabboOpenCredo
 
DevOpsCon Berlin 2017: Project Management from Stone Age to DevOps By Antoni...
DevOpsCon Berlin 2017: Project Management from Stone Age to DevOps  By Antoni...DevOpsCon Berlin 2017: Project Management from Stone Age to DevOps  By Antoni...
DevOpsCon Berlin 2017: Project Management from Stone Age to DevOps By Antoni...OpenCredo
 
Hashidays London 2017 - Evolving your Infrastructure with Terraform By Nicki ...
Hashidays London 2017 - Evolving your Infrastructure with Terraform By Nicki ...Hashidays London 2017 - Evolving your Infrastructure with Terraform By Nicki ...
Hashidays London 2017 - Evolving your Infrastructure with Terraform By Nicki ...OpenCredo
 
Succeeding with DevOps Transformation - Rafal Gancarz
Succeeding with DevOps Transformation - Rafal GancarzSucceeding with DevOps Transformation - Rafal Gancarz
Succeeding with DevOps Transformation - Rafal GancarzOpenCredo
 
Progscon 2017: Serverless Architectures - Rafal Gancarz
Progscon 2017: Serverless Architectures - Rafal GancarzProgscon 2017: Serverless Architectures - Rafal Gancarz
Progscon 2017: Serverless Architectures - Rafal GancarzOpenCredo
 
Vault: Beyond secret storage - Using Vault to harden your infrastructure
Vault: Beyond secret storage - Using Vault to harden your infrastructureVault: Beyond secret storage - Using Vault to harden your infrastructure
Vault: Beyond secret storage - Using Vault to harden your infrastructureOpenCredo
 
ThingMonk 2016 - Concursus Event sourcing for the IOT By Tareq Abedrabbo & Do...
ThingMonk 2016 - Concursus Event sourcing for the IOT By Tareq Abedrabbo & Do...ThingMonk 2016 - Concursus Event sourcing for the IOT By Tareq Abedrabbo & Do...
ThingMonk 2016 - Concursus Event sourcing for the IOT By Tareq Abedrabbo & Do...OpenCredo
 
Spring Boot Microservices vs Akka Actor Cluster
Spring Boot Microservices vs Akka Actor Cluster Spring Boot Microservices vs Akka Actor Cluster
Spring Boot Microservices vs Akka Actor Cluster OpenCredo
 
Microservices Manchester: Microservices and Macro-Economics - A Shorty Histor...
Microservices Manchester: Microservices and Macro-Economics - A Shorty Histor...Microservices Manchester: Microservices and Macro-Economics - A Shorty Histor...
Microservices Manchester: Microservices and Macro-Economics - A Shorty Histor...OpenCredo
 
Microservices Manchester: Security, Microservces and Vault by Nicki Watt
Microservices Manchester:  Security, Microservces and Vault by Nicki WattMicroservices Manchester:  Security, Microservces and Vault by Nicki Watt
Microservices Manchester: Security, Microservces and Vault by Nicki WattOpenCredo
 

More from OpenCredo (17)

Webinar - Design Thinking for Platform Engineering
Webinar - Design Thinking for Platform EngineeringWebinar - Design Thinking for Platform Engineering
Webinar - Design Thinking for Platform Engineering
 
MuCon 2019: Exploring Your Microservices Architecture Through Network Science...
MuCon 2019: Exploring Your Microservices Architecture Through Network Science...MuCon 2019: Exploring Your Microservices Architecture Through Network Science...
MuCon 2019: Exploring Your Microservices Architecture Through Network Science...
 
Goto Chicago; Journeys To Cloud Native Architecture: Sun, Sea And Emergencies...
Goto Chicago; Journeys To Cloud Native Architecture: Sun, Sea And Emergencies...Goto Chicago; Journeys To Cloud Native Architecture: Sun, Sea And Emergencies...
Goto Chicago; Journeys To Cloud Native Architecture: Sun, Sea And Emergencies...
 
Mucon 2018: Heuristics for Identifying Microservice Boundaries By Erich Eichi...
Mucon 2018: Heuristics for Identifying Microservice Boundaries By Erich Eichi...Mucon 2018: Heuristics for Identifying Microservice Boundaries By Erich Eichi...
Mucon 2018: Heuristics for Identifying Microservice Boundaries By Erich Eichi...
 
Journeys To Cloud Native Architecture: Sun, Sea And Emergencies - Nicki Watt
Journeys To Cloud Native Architecture: Sun, Sea And Emergencies - Nicki WattJourneys To Cloud Native Architecture: Sun, Sea And Emergencies - Nicki Watt
Journeys To Cloud Native Architecture: Sun, Sea And Emergencies - Nicki Watt
 
Machine Learning Game Changer for IT - Maartens Lourens
Machine Learning Game Changer for IT - Maartens LourensMachine Learning Game Changer for IT - Maartens Lourens
Machine Learning Game Changer for IT - Maartens Lourens
 
Kafka Summit 2018: A Journey Building Kafka Connectors - Pegerto Fernandez
Kafka Summit 2018: A Journey Building Kafka Connectors - Pegerto FernandezKafka Summit 2018: A Journey Building Kafka Connectors - Pegerto Fernandez
Kafka Summit 2018: A Journey Building Kafka Connectors - Pegerto Fernandez
 
MuCon 2017: A not So(A) Trivial Question by Tareq Abedrabbo
MuCon 2017: A not So(A) Trivial Question by Tareq AbedrabboMuCon 2017: A not So(A) Trivial Question by Tareq Abedrabbo
MuCon 2017: A not So(A) Trivial Question by Tareq Abedrabbo
 
DevOpsCon Berlin 2017: Project Management from Stone Age to DevOps By Antoni...
DevOpsCon Berlin 2017: Project Management from Stone Age to DevOps  By Antoni...DevOpsCon Berlin 2017: Project Management from Stone Age to DevOps  By Antoni...
DevOpsCon Berlin 2017: Project Management from Stone Age to DevOps By Antoni...
 
Hashidays London 2017 - Evolving your Infrastructure with Terraform By Nicki ...
Hashidays London 2017 - Evolving your Infrastructure with Terraform By Nicki ...Hashidays London 2017 - Evolving your Infrastructure with Terraform By Nicki ...
Hashidays London 2017 - Evolving your Infrastructure with Terraform By Nicki ...
 
Succeeding with DevOps Transformation - Rafal Gancarz
Succeeding with DevOps Transformation - Rafal GancarzSucceeding with DevOps Transformation - Rafal Gancarz
Succeeding with DevOps Transformation - Rafal Gancarz
 
Progscon 2017: Serverless Architectures - Rafal Gancarz
Progscon 2017: Serverless Architectures - Rafal GancarzProgscon 2017: Serverless Architectures - Rafal Gancarz
Progscon 2017: Serverless Architectures - Rafal Gancarz
 
Vault: Beyond secret storage - Using Vault to harden your infrastructure
Vault: Beyond secret storage - Using Vault to harden your infrastructureVault: Beyond secret storage - Using Vault to harden your infrastructure
Vault: Beyond secret storage - Using Vault to harden your infrastructure
 
ThingMonk 2016 - Concursus Event sourcing for the IOT By Tareq Abedrabbo & Do...
ThingMonk 2016 - Concursus Event sourcing for the IOT By Tareq Abedrabbo & Do...ThingMonk 2016 - Concursus Event sourcing for the IOT By Tareq Abedrabbo & Do...
ThingMonk 2016 - Concursus Event sourcing for the IOT By Tareq Abedrabbo & Do...
 
Spring Boot Microservices vs Akka Actor Cluster
Spring Boot Microservices vs Akka Actor Cluster Spring Boot Microservices vs Akka Actor Cluster
Spring Boot Microservices vs Akka Actor Cluster
 
Microservices Manchester: Microservices and Macro-Economics - A Shorty Histor...
Microservices Manchester: Microservices and Macro-Economics - A Shorty Histor...Microservices Manchester: Microservices and Macro-Economics - A Shorty Histor...
Microservices Manchester: Microservices and Macro-Economics - A Shorty Histor...
 
Microservices Manchester: Security, Microservces and Vault by Nicki Watt
Microservices Manchester:  Security, Microservces and Vault by Nicki WattMicroservices Manchester:  Security, Microservces and Vault by Nicki Watt
Microservices Manchester: Security, Microservces and Vault by Nicki Watt
 

Recently uploaded

Microsoft 365 Copilot: How to boost your productivity with AI – Part one: Ado...
Microsoft 365 Copilot: How to boost your productivity with AI – Part one: Ado...Microsoft 365 Copilot: How to boost your productivity with AI – Part one: Ado...
Microsoft 365 Copilot: How to boost your productivity with AI – Part one: Ado...Nikki Chapple
 
Moving Beyond Passwords: FIDO Paris Seminar.pdf
Moving Beyond Passwords: FIDO Paris Seminar.pdfMoving Beyond Passwords: FIDO Paris Seminar.pdf
Moving Beyond Passwords: FIDO Paris Seminar.pdfLoriGlavin3
 
The State of Passkeys with FIDO Alliance.pptx
The State of Passkeys with FIDO Alliance.pptxThe State of Passkeys with FIDO Alliance.pptx
The State of Passkeys with FIDO Alliance.pptxLoriGlavin3
 
The Future Roadmap for the Composable Data Stack - Wes McKinney - Data Counci...
The Future Roadmap for the Composable Data Stack - Wes McKinney - Data Counci...The Future Roadmap for the Composable Data Stack - Wes McKinney - Data Counci...
The Future Roadmap for the Composable Data Stack - Wes McKinney - Data Counci...Wes McKinney
 
How to Effectively Monitor SD-WAN and SASE Environments with ThousandEyes
How to Effectively Monitor SD-WAN and SASE Environments with ThousandEyesHow to Effectively Monitor SD-WAN and SASE Environments with ThousandEyes
How to Effectively Monitor SD-WAN and SASE Environments with ThousandEyesThousandEyes
 
Potential of AI (Generative AI) in Business: Learnings and Insights
Potential of AI (Generative AI) in Business: Learnings and InsightsPotential of AI (Generative AI) in Business: Learnings and Insights
Potential of AI (Generative AI) in Business: Learnings and InsightsRavi Sanghani
 
The Role of FIDO in a Cyber Secure Netherlands: FIDO Paris Seminar.pptx
The Role of FIDO in a Cyber Secure Netherlands: FIDO Paris Seminar.pptxThe Role of FIDO in a Cyber Secure Netherlands: FIDO Paris Seminar.pptx
The Role of FIDO in a Cyber Secure Netherlands: FIDO Paris Seminar.pptxLoriGlavin3
 
Emixa Mendix Meetup 11 April 2024 about Mendix Native development
Emixa Mendix Meetup 11 April 2024 about Mendix Native developmentEmixa Mendix Meetup 11 April 2024 about Mendix Native development
Emixa Mendix Meetup 11 April 2024 about Mendix Native developmentPim van der Noll
 
Time Series Foundation Models - current state and future directions
Time Series Foundation Models - current state and future directionsTime Series Foundation Models - current state and future directions
Time Series Foundation Models - current state and future directionsNathaniel Shimoni
 
Generative AI - Gitex v1Generative AI - Gitex v1.pptx
Generative AI - Gitex v1Generative AI - Gitex v1.pptxGenerative AI - Gitex v1Generative AI - Gitex v1.pptx
Generative AI - Gitex v1Generative AI - Gitex v1.pptxfnnc6jmgwh
 
The Fit for Passkeys for Employee and Consumer Sign-ins: FIDO Paris Seminar.pptx
The Fit for Passkeys for Employee and Consumer Sign-ins: FIDO Paris Seminar.pptxThe Fit for Passkeys for Employee and Consumer Sign-ins: FIDO Paris Seminar.pptx
The Fit for Passkeys for Employee and Consumer Sign-ins: FIDO Paris Seminar.pptxLoriGlavin3
 
React Native vs Ionic - The Best Mobile App Framework
React Native vs Ionic - The Best Mobile App FrameworkReact Native vs Ionic - The Best Mobile App Framework
React Native vs Ionic - The Best Mobile App FrameworkPixlogix Infotech
 
Unleashing Real-time Insights with ClickHouse_ Navigating the Landscape in 20...
Unleashing Real-time Insights with ClickHouse_ Navigating the Landscape in 20...Unleashing Real-time Insights with ClickHouse_ Navigating the Landscape in 20...
Unleashing Real-time Insights with ClickHouse_ Navigating the Landscape in 20...Alkin Tezuysal
 
New from BookNet Canada for 2024: Loan Stars - Tech Forum 2024
New from BookNet Canada for 2024: Loan Stars - Tech Forum 2024New from BookNet Canada for 2024: Loan Stars - Tech Forum 2024
New from BookNet Canada for 2024: Loan Stars - Tech Forum 2024BookNet Canada
 
Design pattern talk by Kaya Weers - 2024 (v2)
Design pattern talk by Kaya Weers - 2024 (v2)Design pattern talk by Kaya Weers - 2024 (v2)
Design pattern talk by Kaya Weers - 2024 (v2)Kaya Weers
 
Arizona Broadband Policy Past, Present, and Future Presentation 3/25/24
Arizona Broadband Policy Past, Present, and Future Presentation 3/25/24Arizona Broadband Policy Past, Present, and Future Presentation 3/25/24
Arizona Broadband Policy Past, Present, and Future Presentation 3/25/24Mark Goldstein
 
TeamStation AI System Report LATAM IT Salaries 2024
TeamStation AI System Report LATAM IT Salaries 2024TeamStation AI System Report LATAM IT Salaries 2024
TeamStation AI System Report LATAM IT Salaries 2024Lonnie McRorey
 
Glenn Lazarus- Why Your Observability Strategy Needs Security Observability
Glenn Lazarus- Why Your Observability Strategy Needs Security ObservabilityGlenn Lazarus- Why Your Observability Strategy Needs Security Observability
Glenn Lazarus- Why Your Observability Strategy Needs Security Observabilityitnewsafrica
 
So einfach geht modernes Roaming fuer Notes und Nomad.pdf
So einfach geht modernes Roaming fuer Notes und Nomad.pdfSo einfach geht modernes Roaming fuer Notes und Nomad.pdf
So einfach geht modernes Roaming fuer Notes und Nomad.pdfpanagenda
 
Use of FIDO in the Payments and Identity Landscape: FIDO Paris Seminar.pptx
Use of FIDO in the Payments and Identity Landscape: FIDO Paris Seminar.pptxUse of FIDO in the Payments and Identity Landscape: FIDO Paris Seminar.pptx
Use of FIDO in the Payments and Identity Landscape: FIDO Paris Seminar.pptxLoriGlavin3
 

Recently uploaded (20)

Microsoft 365 Copilot: How to boost your productivity with AI – Part one: Ado...
Microsoft 365 Copilot: How to boost your productivity with AI – Part one: Ado...Microsoft 365 Copilot: How to boost your productivity with AI – Part one: Ado...
Microsoft 365 Copilot: How to boost your productivity with AI – Part one: Ado...
 
Moving Beyond Passwords: FIDO Paris Seminar.pdf
Moving Beyond Passwords: FIDO Paris Seminar.pdfMoving Beyond Passwords: FIDO Paris Seminar.pdf
Moving Beyond Passwords: FIDO Paris Seminar.pdf
 
The State of Passkeys with FIDO Alliance.pptx
The State of Passkeys with FIDO Alliance.pptxThe State of Passkeys with FIDO Alliance.pptx
The State of Passkeys with FIDO Alliance.pptx
 
The Future Roadmap for the Composable Data Stack - Wes McKinney - Data Counci...
The Future Roadmap for the Composable Data Stack - Wes McKinney - Data Counci...The Future Roadmap for the Composable Data Stack - Wes McKinney - Data Counci...
The Future Roadmap for the Composable Data Stack - Wes McKinney - Data Counci...
 
How to Effectively Monitor SD-WAN and SASE Environments with ThousandEyes
How to Effectively Monitor SD-WAN and SASE Environments with ThousandEyesHow to Effectively Monitor SD-WAN and SASE Environments with ThousandEyes
How to Effectively Monitor SD-WAN and SASE Environments with ThousandEyes
 
Potential of AI (Generative AI) in Business: Learnings and Insights
Potential of AI (Generative AI) in Business: Learnings and InsightsPotential of AI (Generative AI) in Business: Learnings and Insights
Potential of AI (Generative AI) in Business: Learnings and Insights
 
The Role of FIDO in a Cyber Secure Netherlands: FIDO Paris Seminar.pptx
The Role of FIDO in a Cyber Secure Netherlands: FIDO Paris Seminar.pptxThe Role of FIDO in a Cyber Secure Netherlands: FIDO Paris Seminar.pptx
The Role of FIDO in a Cyber Secure Netherlands: FIDO Paris Seminar.pptx
 
Emixa Mendix Meetup 11 April 2024 about Mendix Native development
Emixa Mendix Meetup 11 April 2024 about Mendix Native developmentEmixa Mendix Meetup 11 April 2024 about Mendix Native development
Emixa Mendix Meetup 11 April 2024 about Mendix Native development
 
Time Series Foundation Models - current state and future directions
Time Series Foundation Models - current state and future directionsTime Series Foundation Models - current state and future directions
Time Series Foundation Models - current state and future directions
 
Generative AI - Gitex v1Generative AI - Gitex v1.pptx
Generative AI - Gitex v1Generative AI - Gitex v1.pptxGenerative AI - Gitex v1Generative AI - Gitex v1.pptx
Generative AI - Gitex v1Generative AI - Gitex v1.pptx
 
The Fit for Passkeys for Employee and Consumer Sign-ins: FIDO Paris Seminar.pptx
The Fit for Passkeys for Employee and Consumer Sign-ins: FIDO Paris Seminar.pptxThe Fit for Passkeys for Employee and Consumer Sign-ins: FIDO Paris Seminar.pptx
The Fit for Passkeys for Employee and Consumer Sign-ins: FIDO Paris Seminar.pptx
 
React Native vs Ionic - The Best Mobile App Framework
React Native vs Ionic - The Best Mobile App FrameworkReact Native vs Ionic - The Best Mobile App Framework
React Native vs Ionic - The Best Mobile App Framework
 
Unleashing Real-time Insights with ClickHouse_ Navigating the Landscape in 20...
Unleashing Real-time Insights with ClickHouse_ Navigating the Landscape in 20...Unleashing Real-time Insights with ClickHouse_ Navigating the Landscape in 20...
Unleashing Real-time Insights with ClickHouse_ Navigating the Landscape in 20...
 
New from BookNet Canada for 2024: Loan Stars - Tech Forum 2024
New from BookNet Canada for 2024: Loan Stars - Tech Forum 2024New from BookNet Canada for 2024: Loan Stars - Tech Forum 2024
New from BookNet Canada for 2024: Loan Stars - Tech Forum 2024
 
Design pattern talk by Kaya Weers - 2024 (v2)
Design pattern talk by Kaya Weers - 2024 (v2)Design pattern talk by Kaya Weers - 2024 (v2)
Design pattern talk by Kaya Weers - 2024 (v2)
 
Arizona Broadband Policy Past, Present, and Future Presentation 3/25/24
Arizona Broadband Policy Past, Present, and Future Presentation 3/25/24Arizona Broadband Policy Past, Present, and Future Presentation 3/25/24
Arizona Broadband Policy Past, Present, and Future Presentation 3/25/24
 
TeamStation AI System Report LATAM IT Salaries 2024
TeamStation AI System Report LATAM IT Salaries 2024TeamStation AI System Report LATAM IT Salaries 2024
TeamStation AI System Report LATAM IT Salaries 2024
 
Glenn Lazarus- Why Your Observability Strategy Needs Security Observability
Glenn Lazarus- Why Your Observability Strategy Needs Security ObservabilityGlenn Lazarus- Why Your Observability Strategy Needs Security Observability
Glenn Lazarus- Why Your Observability Strategy Needs Security Observability
 
So einfach geht modernes Roaming fuer Notes und Nomad.pdf
So einfach geht modernes Roaming fuer Notes und Nomad.pdfSo einfach geht modernes Roaming fuer Notes und Nomad.pdf
So einfach geht modernes Roaming fuer Notes und Nomad.pdf
 
Use of FIDO in the Payments and Identity Landscape: FIDO Paris Seminar.pptx
Use of FIDO in the Payments and Identity Landscape: FIDO Paris Seminar.pptxUse of FIDO in the Payments and Identity Landscape: FIDO Paris Seminar.pptx
Use of FIDO in the Payments and Identity Landscape: FIDO Paris Seminar.pptx
 

Visual Intro to Event Sourcing and CQRS

  • 1. A visual introduction to
 Event Sourcing and CQRS 1 @nicusX https://opencredo.com/author/lorenzo/ Lorenzo Nicora Senior Consultant @ OpenCredo
  • 2. 2 A couple of concepts from DDD Aggregate (Current) State
 of the Aggregate Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 3. 3 Once upon a time… Everything is synchronous Request - Response Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 4. 4 Scaling up… Updates —> Locks —> Contention! <— Block <— Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 5. 5 Let’s go Asynchronous Pwd —> “secret” Pwd —> “12345” Pwd —> “54321” Pwd —> “secret” Pwd —> “54321” Pwd —> “12345” ===>
 Out of 
 Order Asynchronous, Message-driven Request/Response ACID Transaction Distributed, Message-based 
 —> No order guaranteed Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 6. 6 Command Sourcing 💡 • Append Only —> No Contention • Build State from Command history Write fast, Think later K/V Store Distributed Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 7. Command “Submit Order!” —> A request (imperative sentence) —> May fail —> May affect multiple Aggregates 7 Commands vs Events ✉ Rebuild Aggregate State 
 from Commands Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 8. 8 Event “Order submitted” —> Statement of facts (past tense) —> Never fails —> May affect a single Aggregate ✉ Rebuild Aggregate State 
 from Events Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 9. 9 Commands to Events (DDD patterns: Aggregate / Process Manager) X Y Z Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 10. 10 Command > Event Sourcing 💡 Think a little, Write, Think later Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 11. 11 Event Sourcing In many domains Commands Events Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 12. 12 Additional Benefits Easy
 Eventual Business Consistency —> Corrective Events Robust to data corruption (bugs, fat fingers…) —> Rebuild state ignoring wrong events Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 13. 13 Additional Benefits History (for free) Rebuild State 
 at a point in Time Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 14. 14 Main Benefit Scalable —> Append only -> Fits distributed k/v stores —> Low-latency writes —> Allows asynchronous processing Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 15. What about reads? 15 Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 16. 16 Retrieving the State How do I retrieve the State? “Get details of Order ‘AB123’” ❔ not very efficient, but… …may work Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 17. 17 Querying (Searching) the State ❓ ❓ How do query the State? “Get all Orders delivered to ‘SE1 0NZ’” ❓ ❓ Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 18. 18 CQRS Command Query Responsibility Segregation 💡 Separate • Code • muService • Datastore -> Update -—> Retrieve “Query” datastore is downstream Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 19. 19 Not a new idea Specialised Downstream Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 20. 20 CQRS and Event Sourcing Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 21. 21 Materialised Views 
 (of current State) Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 22. 22 Materialised Views (of State) Latest (known) State (Persistent)
 Rebuildable from Events In Memory
 K/V Store Graph … RDBMS Delayed 💡 Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 23. 23 Materialised View of State Query a RDBMS?!? Wasn’t it the old way? ❓ RDBMS is just one of our options:
 easy to use, easily become a bottleneck Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 24. 24 Materialised Views of State * Views are optimised for 
 specific query use cases —> multiple Views from same Events * Updated asynchronously, delayed —> to Scale -> may reorder Events Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 25. 25 Materialised Views of State * Views can be rebuilt from Events Event Log is our Source of Truth * Easy to evolve or fix —> change or fix logic; rebuild view from events (not the View) Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 26. 26 Indexes Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 27. 27 Indexes Search Engines
 K/V Stores • Optimised for querying (less for retrieving) • Latest State; rebuild on the fly 💡 Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 28. 28 Hybrid solutions Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 29. 29 Hybrid solutions: e.g. Snapshots • Speed up rebuilding the current State • Use recent Events to rebuild up-to-date 💡 Long delayed Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 30. 30 Eventual (Business) Consistency Guess —> Compensate—> Apologies Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 31. 31 Eventual Consistency: Sagas StatefulOut of band Corrective Command 
 or Event Saga Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 32. 32 Lesson
 from the Trenches Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 33. 33 Lesson Learned #1 If you put data in… …you will eventually
 have to get them out! The “Query” side 
 is not secondary Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 34. 34 Lessons Learned #2 In old days:
 normalising one DB 
 to support as many queries as possible With CQRS: 
 multiple denormalised “data stores”
 optimised for different queries No single “Q” implementation 
 for all your queries Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 35. 35 Lessons Learned #3 A central, shared Event Store
 may not be the best option No Event-sourced Monolith Prefer persistence 
 per Bounded-Context Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 36. +++ Summing up +++ 36 Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 37. 37 ES/CQRS Optimal Use Cases High Volume Low Latency writes (big data) Event Sourcing + CQRS 😋 Out-of-order Commands/Events
 (IoT) Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 38. 38 ES/CQRS Drawbacks x No “One-Size-Fits-All”
 —> Multiple “Q” implementations x Delayed reads x No ACID Transactions x Additional complexity (!) 🙁 Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 39. 39 ES/CQRS Benefits + No “One-Size-Fits-All” —> “Q” are optimised for use cases + Eventual (Business) Consistency + History, Temporal queries + Robust to data corruption 😀 Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 40. That’s all, Folks! 40 Lorenzo Nicora Intro to Event Sourcing and CQRS
  • 41. ??? Questions ??? 41 Thanks. ⏳ Lorenzo Nicora Intro to Event Sourcing and CQRS