EventStore

A fast, production ready Ruby implementation of an EventStore (A+ES). For more detail on what an EventStore is checkout what Gregg Young has to stay about it: http://codebetter.com/gregyoung/2010/02/20/why-use-event-sourcing/

Usage

Currently, EventStore supports postgres and vertica adapters.

Connecting in Development or Test

EventStore.postgres(:development)
EventStore.postgres #test

EventStore.vertica(:development)
EventStore.vertica #test

Connecting in Production or Elsewhere

EventStore.custom_config(redis_config, database_config)
#The redis and database configs are the standard hashes expected by the Redis.new and Sequel.connect -- we just pass them directly in

Notes on Connecting

  • EventStore expects a database called history_store to exist.
  • postgres will try to connect in dev and test mode as 'nexia:Password1@localhost'

  • postgres will assume a port of 5432 if one is not supplied.

  • vertica expects to find an environment variable (VERTICA_HOST) to be set and will use this as the host in dev and test mode

  • vertica will assume its default port if one is not supplied.

  • vertica will try to connect in dev and test mode as 'dbadmin:password@[vertica_host]'

  • To find the ip address of vertica on your local box (running in a vm):

    1. open Settings -> Network and select Wi-Fi
    2. open a terminal in the VM
    3. do /sbin/ifconfig (ifconfig is not in $PATH)
    4. the inet address for en0 is what you want Hint: if it just hangs, you have have the wrong IP

Creating a client

client = EventStore::Client.new(aggregate_id)

# transactionally append an array events to an aggregate's event stream
client.append(events)

# Get a list of events representing a snapshot of the aggregate's current state (fast)
client.snapshot

# Get an aggregate's entire event stream (can be very large)
client.event_stream

# Get an aggregate's event stream starting from a version
client.event_stream_from(347)

# event_stream_from optionally takes a limit
client.event_stream_from(347, 1000)

# Get the last event for an aggregate
client.peek

# Get the current version of an aggregate
client.version

# Drop all the events associated with an aggregate, including its snapshot
client.destroy!