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Version: 1.6

Model configuration

This part of configuration defines how to configure Components and some of the runtime behaviour (e.g. error handling) for a given scenario type (Lite or Flink engine). It is processed not only at the Designer but also passed to the execution engine (e.g. Flink), that’s why it’s parsed and processed a bit differently:

  • Defaults can be defined in defaultModelConfig.conf. Standard deployment (e.g. with docker sample) has it here.
  • defaultModelConfig.conf is currently resolved both on designer (to extract information about types of data or during scenario testing) and on execution engine (e.g. on Flink or in Lite runtime). That’s why all environment variables used there have to be defined also on all Flink/Lite engine runtime hosts (!). This is a technical limitation and may change in the future.
  • Some Components can use a special mechanism which resolves and adds additional configuration during deployment, which is then passed to the execution engine. Such configuration is read and resolved only at the designer. Example: OpenAPI enrichers need to read its definition from external sites - so e.g. Flink cluster does not have to have access to the site with the definition.

Look at configuration areas to understand where Model configuration should be placed in Nussknacker configuration.

ClassPath configuration​

Nussknacker looks for components and various extensions in jars on the Model classpath, default config example here to see where classpath can be configured.

By default, the following configuration is used:

classPath: ["model/defaultModel.jar", "model/flinkExecutor.jar", "components/flink", "components/common"]

Make sure you have all necessary entries properly configured:

  • Jar with model - unless you used custom model, this should be model/defaultModel.jar
  • All jars with additional components, e.g. "components/flink/flinkBase.jar", "components/flink/flinkKafka.jar"
  • flinkExecutor.jar for Flink engine. This contains executor of scenarios in Flink cluster.

Note that as classPath elements you can use:

If the given path element in the classPath is relative, it should be relative to the path determined by the $WORKING_DIR environment variable.

Components configuration​

Nussknacker comes with a set of provided components. Some of them (e.g. filter, variable, aggregations in Flink, for-each, union) are predefined and accessible by default. Others need additional configuration - the most important ones are enrichers, where you have to set e.g. JDBC URL or external service address.

Check documentation of available components that you can configure:

  • OpenAPI Supports accessing external APIs directly from scenario
  • SQL Supports access to SQL database engines

Configuration of component providers​

Below you can see typical component configuration, each section describes configuration of one component provider.

  components {
    sqlHsql {
      providerType: sql
      jdbcUrl: jdbc:hsql...//
      admin/pass
    }
    sqlOracle {
      providerType: sql
      jdbcUrl: jdbc:oracle...//
      admin/pass
    }
    prinzH20 {
      providerType: prinzH20
      h2oLocation:
    }
    prinzMlFlow {
      #this is not needed, as configuration is named just as provider
      #providerType: prinzMLFlow
      mlFlowUrl:
    }
    #we can disable particular component provider, if it's not needed in our installation
    #note: you cannot disable certain basic components like filter, variable, choice and split
    aggregation {
      disabled: true
    }
  }

Configuration of UI attributes of components​

In model configuration you can also define some UI attributes of components. This can be useful for tweaking of appearance of generated components (like from OpenAPI), in most cases you should not need to defined these settings. The settings you can configure include:

  • icons - icon property
  • documentation - docsUrl property
  • should component be disabled - disabled property
  • in which toolbox panel the component should appear (componentGroup property)
  • params configuration (allows to override default component settings):
    • editor - BoolParameterEditor, StringParameterEditor, DateParameterEditor etc.
    • validators - MandatoryParameterValidator, NotBlankParameterValidator, RegexpParameterValidator
    • defaultValue
    • label

Example (see dev application config for more examples):

  componentsUiConfig {
    customerService {
      params {
        serviceIdParameter {
            defaultValue: "customerId-10"
            editor: "StringParameterEditor"
            validators: [ 
              {
                type: "RegExpParameterValidator"
                pattern: "customerId-[0-9]*"
                message: "has to match customer id format"
                description: "really has to match..."
              }
            ]
            label: "Customer id (from CRM!)
        }
      }
      docsUrl: "https://en.wikipedia.org/wiki/Customer_service"
      icon: "icon_file.svg"
    }
  }

You can add additional links that will be shown in Components tab. They can be used e.g. to point to custom dashboards with component performance or point to some external system (link to documentation is configured by default). The config format is as follows:

componentLinks: [
  {
    id: "sourceSystem"
    title: "Source system"
    icon: "/assets/components/CustomNode.svg"
    url: "https://myCustom.com/dataSource/$componentName" 
    supportedComponentTypes: ["openAPIEnricher1"]
  }
]

Fields title, icon, url can contain templates: $componentId nad $componentName which are replaced by component data. Param supportedComponentTypes means component's types which can support links.

Component group mapping​

You can override default grouping of basic components in toolbox panels with componentsGroupMapping setting. Component names are keys, while values are toolbox panels name (e.g. sources, enrichers etc.) |

Scenario's additional properties​

It's possible to add additional properties for scenario. They can be used for allowing more detailed scenario information (e.g. pass information about marketing campaign target etc.), they can also be used in various Nussknacker extensions:

Example (see dev application config for more examples):

additionalPropertiesConfig {
  campaignType: {
    editor: { type: "StringParameterEditor" }
    validators: [ { type: "MandatoryParameterValidator" } ]
    label: "Campaign type"
    defaultValue: "Generic campaign"
  }
  ...
}

Configuration is similar to component configuration