3.1.0

New Features

• Commit save concurrency exception handling
  Concurrency exceptions can occur in a race condition where two messages are
  attempting to change the state of an aggregate instance. This can often be
  resolved by simply re-handling the message, which is what the Router now
  does if this exception bubbles up during the save operation.
  This should be safe from endless loops, because if the aggregate's state
  has since changed rendering the message now invalid, a domain exception
  will be thrown, which is handled elsewhere being an application concern.
• New index { "_id": 1, "receivers.appId": 1 } on commits collection to
  optimise commit publishing.
• projectionRebuilder.rebuild now returns a response object containing an
  error and result, which the former will be null if no non-fatal errors were
  thrown. The result contains a message and duration property.
• ProjectionRebuilder now logs detailed debug information, and two info
  updates to provide feedback at the desired level.

Changes

• Commits made in other apps will now only be processed if they contain
  messages with registered handlers in the current app. Prior to every
  commit would be returned by the observer, and then it was decided to
  publish/send, or ignore. This changes the outcome of adding handlers
  in to existing messages, as it will process all from the start of the store,
  which may or may not be desired. It's up to the application to control this
  but is now more flexible and the system can be brought up to a consistent
  state as if the handlers were in place the whole time. Consider this
  carefully!
• Logging has been made more production-friendly, pushing some of the noisy info
  entries from the commit call down to debug. In effect, you could log debug to
  a local file and rotate as needed, and info to an external system that gives you
  the system-level updates rather than every action being taken.
• eventCorrelationProperty of processes are now converted to a string if a Guid.
• ProjectionRebuilder gracefully handles errors, reapplying the backup and resetting
  telling the projection to exitRebuildMode before re-throwing the error.

Future breaking, now depreciated

• commitPublisher.publishCommit(commit)
  now use commitPublisher.publishChanges(changes, commitId)

Bug Fixes

• Commit processing timeout had a bug that caused the publisher to fail
  commits that most likely had already been fully processed, due to the timeout
  reference being lost. Failing a commit that has already
  been processed was causing the commit records to be left in an invalid state.
  This fix also places a guard to protect against
  race conditions in the event of a genuine timeout, or redelivery via the
  infrastructure.
• Now the repository only calls aggregate.replayHistory if there have been
  events since the last snapshot.
• Fixes a non-critical bug with the Snapshotter where every new aggregate
  instance would have the snapshot generated after the commit is added rather
  than waiting for the version specified in configuration. This is a
  performance improvement, particularly for batch importing.

3.0.1

Changes to projection rebuilder

• Space.eventSourcing.ProjectionRebuilder is no longer throwing an error if there is no data to insert into collection after rebuilding is done. Info message is now logged instead.

3.0.0

3.0.0

New Features

Snapshotting upgrade

• Now handled by the module automatically, default to caching the state every 10 versions.

• Configure using:

  • Configuration.eventSourcing.snapshotting.enabled = true or

  SPACE_ES_SNAPSHOTTING_ENABLED='true'

  • Configuration.eventSourcing.snapshotting.frequency = 20
    or

  SPACE_ES_SNAPSHOTTING_FREQUENCY=20

  • SPACE_ES_SNAPSHOTTING_COLLECTION_NAME='my_collection'

New helpers

• Aggregate::_eventPropsFromCommand(command) is an internal helper function
  eliminating the boilerplate of mapping targetId from the command to sourceId
  and manually setting the version prop.

Module

• This package now mixes in specific interfaces Routers and Projections
  for better clarity in your modules/application that depends on Space.eventSourcing.

Router

Events can be automatically routed to processes and aggregates based on a correlation
property, negating the need for lookup collections:

Space.eventSourcing.Router.extend(Space.accounts, 'RegistrationsRouter', {

  aggregate: Space.accounts.Registration,
  initializingCommand: Space.accounts.Register,

  routeEvents: [
    Space.accounts.UserCreated,
    Space.accounts.UserCreationFailed,
    Space.accounts.AccountCreated
  ],

  eventCorrelationProperty: 'registrationId'

});

Commit Publisher

The state of any Commit Publish action is now being managed, with any errors
thrown while processing are caught and used to fail the attempt.
There's also a timeout option to autofail the attempt in the case where a
problem occurs without an error being thrown. This defaults to 60 seconds
but can be configured using the ENV or Module Config APIs

• SPACE_ES_COMMIT_PROCESSING_TIMEOUT=2000 or
  Configuration.eventSourcing.commitProcessing.timeout = 2000

Domain Error handling

Now when domain exceptions are thrown in an aggregate, the router publishes a
special event Space.domain.Exception that can be subscribed to and used for
process integration. The event has two custom properties thrower and error.

Breaking Changes

• Must be running Meteor 1.2.0.1 or later.

Dependencies forcing API changes

• This version uses space:base 4.x which includes breaking changes.
  Please see the changelog.
• This version uses space:messaging 3.x which includes breaking changes.
  Please see the changelog.

Commits Collection

• Module now manages the commits collection
• Instead of passing in a collection, use the Configuration and/or ENVs.
• Default collection name has been changed from space_cqrs_commitStore
• Events are now persisted in a query-friendly format! Prior to this the data was
  stored in a JSON string which was optimal for persistence, but you would have to
  maintain a projection in order to query the historical data. Moving from 2.x to
  3.x will require data migration, but we feel this was necessary and will be
  worthwhile for the huge gain in querying capability.

Projector and Projection API changes

• Projector => ProjectionRebuilder
• ProjectionRebuilder::replay(options) => rebuild(projections, options)
• Projection::enterReplayMode() => enterRebuildMode()
• Projection::exitReplayMode() => exitRebuildMode()

Thanks to all the new people on the team who made this awesome release possible:

• Rhys Bartels-Waller
• Darko Mijić
• Adam Desivi

👏