Barenboim
Barenboim is prepared to tackle with data streaming dependencies in concurrent flows.
If your application works with a data streaming and your incoming events could have dependencies between them, the app can have problems when:
- The Application which is sending the data is not sending the data in the right order.
- Your Application is treating the data concurrently therefore the order is not ensured.
Installation
Add barenboim to your list of dependencies in mix.exs:
def deps do
[{:barenboim, "~> 0.3.0"}]
end
Configuration
Barenboim uses poolboy and you can configure it depending on your needs:
config :barenboim,
pool_domain: :global, # default :local
pool_size: 20, # default 10
max_overflow: 3 # default 5
You can also configure a delay for a reminder notification. A reminder notification is sent in order to avoid corner cases (notification between the data access and the registration of a dependency). This time (milliseconds) should be defined depending on your data access function time (see next section).
config :barenboim,
reminder_time: 50 # default 100
How to use it
Define the function that will retrieve the dependency data where dependency_ref is the reference of your data
and call Barenboim.get_data. You can also specify a time out in milliseconds.
fun = fn(dependency_ref) -> MyDataModule.get(dependency_ref) end
{:ok, data} = Barenboim.get_data(dependency_ref, fun)
Meanwhile, the flow that is processing a new event has to notify when the data is available for others.
Barenboim.notify({:reference, dependency_ref})
Or you can even attach the data:
Barenboim.notify({:data, dependency_ref, dependency_data})
Test
Run the tests.
mix test