# Upgrading to v2.0

The following breaking changes were introduced in version 1.0:

* Lag reporting is now optional, and controlled by `config.report_lag`. To
  re-enable it, you must set `config.report_lag` to true. We recommend you
  only set this to true on production or staging environments and not
  development or test.
* Topics that have no keys now must use `key_config none: true` instead
  of `key_config plain: true`.
* `KafkaPublishFailure` has been removed - any code that relies on it must
  likewise be removed, and the database table can also be dropped. You can
  also remove any reference to the `payloads_for_resend` method defined
  on your producers.
    * Its replacement is the new `db` [publish backend](../README.md#database-backend).
      Note that to use this option, you need to have [activerecord-import](https://github.com/zdennis/activerecord-import)
      in your Gemfile.
* `KafkaSource` will now send messages inside a transaction rather than
  after a commit. Any code (e.g. RSpecs) that relies on the previous 
  behavior must be modified.
* `TestHelpers` no longer automatically stub producers and consumers, to aid
  in the integration testing scenario. Instead, you should add a `before(:each)`
  hook that calls `stub_producers_and_consumers!` Along with this, the
  `kafka_integration` metadata key that used to check for this behavior
  is no longer supported or needed, and can be removed from any tests that
  use it. This allows for more flexibility and explicitness 
  in how to determine if tests are integration tests.
* The `PlatformSchemaValidation` class has moved to the `Utils` module, so
  it is now `FlippRubyKafka::Utils::PlatformSchemaValidation`.

Additional changes introduced in v2.0 (which uses Deimos under the hood):

* Removed the `sync_produce` option as it's now redundant with the 
  `publish_backend` option. `publish_backend` can be set to either
  `:kafka` or `:kafka_async` to reproduce this option.
* Changed the name of `rake phobos:start` to `rake deimos:start`.
* Configuration is now mostly handled by flipp-ruby-kafka, including
  defaults for the MS platform. See README for how configuration should
  look now.