The slides from the Europe Virtual ALT.NET Presentation on the CQRS EventStore v3: http://blog.jonathanoliver.com/2011/10/eventstore-evan-presentation/

1. Europe Virtual ALT.NET, 25 October 2011
Jonathan Oliver
Using and Abusing

2.  Founder: SmartyStreets (smartystreets.com)
 Founder, co-host: Distributed Podcast
 Committer, NServiceBus & Autofac
 Project owner, CQRS EventStore

3.  Finances the EventStore project
 Started in 2006 (as Qualified Address)
 All your street address are belong to us
 My personal guinea pig
 Fully geo-distributed

4.  Messaging
 SOA
 DDD
 CQRS (strict definition)
 Event Sourcing
 CQRS Architecture

5.  Hand-crafted SQL and stored procedures
 Canonical data model
 Application integration via shared database
 Generated DAL

6.  Temporal database design
 Messaging
 Breakthrough—Putting DBs in their place
 Greg Young—InfoQ and DevTeach Videos

7.  Capturing business intent
 Rebuild state from events
 Rewind, pause, fast-forward
 Build alternate models
 Immutable data is crazy scalable
 Complete audit

8.  It’s not a framework—I hate frameworks
 It doesn’t permeate your code
 You can swap it out and/or build your own
 Nothing existed at the time—March 2009
 Implementation reflects the developer

9.  Goal: technology is an implementation detail
 Transactions typically exist in SQL land
 Lots of interesting alternatives appearing
 Momentum around NoSQL increasing
 Two-phase commit virtually non-existent

10.  Absorbing transactions
 Cross-resource transactional consistency
 Commits
 Exposing a robust, easy-to-use model

11. “Repository” App / Service Layer Dispatcher / Bus
EventStore
“ISession” commit
Event Stream
commit
“ISessionFactory” Event Store Pipeline Hooks
“NHibernate Magic”
Persistence Engine Serializer
Disk, DB, Memory, etc. Durable Storage
(Snapshotting and some advanced capabilities have been ommitted)

12. Transaction #1 Message Handler EventStore
Async Dispatch
Scheduler
commit ack
•Optimistic Concurrency
• Idempotency/De-duplication Disk
Transaction #2
Dispatch Messaging
Wire Protocol
Scheduler Technology
Mark as dispatched
Transaction #3
EventStore
Disk

13.  Streams vs. Aggregates
 Usage Example
 Implementation

14.  Pipes and filters
 Filter out, modify, up-convert
 Select, Precommit, and Postcommit
 Implementation

15.  Synchronous vs. Asynchronous
 Any bus, broker, or messaging technology
 Any serialization mechanism
 Production example
 Implementation

16.  XML, JSON/BSON, Protocol Buffers, Thrift,
MessagePack, Avro
 Serialization pipeline
 Implementation

17.  The primary storage engine
 Easy to understand
 Great management tools
 Proven, mature implementation
 10+ flavors (SQL Server, MySQL, SQLite, etc.)
 Code

18.  Easy alternative for .NET
 Great commercial support
 Great management tools
 Responsive community + Oren/Ayende
 Gotcha: 2PC and repeatable reads

19.  Highly robust engine
 Established as a primary NoSQL engine
 Lots of management tools
 Code

20.  CouchDB
 Amazon
 Azure
 Oracle
 Redis
 Cassandra
 .NET System.IO APIs

21.  Completely optional
 Avoiding additional dependencies
 Can use StructureMap, Autofac, Ninject, etc.

22.  Spike code that worked too well
 Simple, opinionated “DDDD” framework
 Purposefully minimalistic
 “Essence” to be merged into EventStore

23. Blog: blog.jonathanoliver.com
Twitter jonathan_oliver
GitHub github.com/joliver