NStack Concepts

Example

We can express this within the NStack scripting language locally as follows (it can help to think of it akin to Bash-style piping for microservices),

module Demo:0.1.0 {
  import NStack.Transformers:0.1.4 as T
  import Acme.Classifiers:0.3.0 as C

  // our analytics workflow
  def workflow = Sources.Postgresql<(Text, Int)>
                 | T.transform { strength = 5 }
                 | C.classify { model = "RandomForest" }
                 | Sinks.S3blob<Text>
}

Intro Screencast

Modules

A module is a piece of code that has been deployed to NStack, either by you or someone else. It has an input schema and an output schema, which defines what kind of data it can receive, and the kind of data that it returns.

Sources & Sinks

• A source is something which emits a stream of data.
• A sink is something which can receive a stream of data.

Example sources and sinks are databases, files, message-queues, and HTTP endpoints. Like modules, you can define the input and output schemas for your sources and sinks.

Workflows

Modules, sources, and sinks can be combined together to build workflows. This is accomplished using the NStack Workflow Language, a simple, high-level language for connecting things together on the NStack Platform.

Processes

When a workflow is started, it becomes a running process. You can have multiple processes of the same workflow.