OrleansEventStoreProvider

An Orleans StreamProvider over EventStore

EventStore is a Event Sourcing provider enabling immutable data streams for applications such as CQRS and other event-sourced applications.

https://geteventstore.com/

Enabling EventStore in Orleans

In order to enable the use of EventStore in Orleans, we need to build a custom StreamProvider, which this repository provides.

This is a proof of concept repository, and not yet in use in Production.

Implemented Features

• Can subscribe to an EventStore stream using Orleans StreamNamespace as the EventStore Stream identifier.
• Can subscribe to an EventStore stream, meaning you will receive new events after Subscription.
• Can push messages to an EventStream using the StreamNamespace as the EventStore Stream identifier.

Serialization

Default ResolvedEvent Data serialization is Json, as indicated by the value of the IsJson flag on the EventStore ResolvedMessage.

You can override the Serialization by specifying a field named encoding in the Metadata of the Event. If the ResolvedEvent.IsJson flag is false, Meta is deserialized by Json, and the field encoding is checked and allows the use of the following deserialization mechanisms.

• Json
• MsgPack

Not Yet Implemented Features

• The use of an Orleans StreamGuid has no effect.
• Subscribing at a point to a Stream - meaning you are not currently able to read from the Start or any Position in a Stream.

Configuration

The actual EventStoreConnection underneath can be configured using the ConnectionString property of the Provider Configuration. The settings available for ConnectionString are documented here: http://docs.geteventstore.com/dotnet-api/3.9.0/connecting-to-a-server/#connection-string

Example

<Provider Type="Orleans.Providers.Streams.EventStore.EventStoreProvider"
          Name="CustomProvider"
          ConnectionString="ConnectTo=tcp://admin:changeit@localhost:1113" />