tDynamoDBLookupInput properties for Apache Spark Streaming

Use an existing connection

Select this check box and in the Component List drop-down list, select the desired connection component to reuse the connection details you already defined.

Access Key

Enter the access key ID that uniquely identifies an AWS Account. For further information about how to get your Access Key and Secret Key, see Getting Your AWS Access Keys.

Secret Key

Enter the secret access key, constituting the security credentials in combination with the access Key.

To enter the secret key, click the [...] button next to the secret key field, and then in the pop-up dialog box enter the password between double quotes and click OK to save the settings.

Region

Specify the AWS region by selecting a region name from the list or entering a region between double quotation marks (e.g. "us-east-1") in the list. For more information about the AWS Region, see Regions and Endpoints.

Use End Point

Select this check box and in the Server Url field displayed, specify the Web service URL of the DynamoDB database service.

Schema and Edit schema

A schema is a row description. It defines the number of fields (columns) to be processed and passed on to the next component. When you create a Spark Job, avoid the reserved word line when naming the fields.

• Built-In: You create and store the schema locally for this component only.

• Repository: You have already created the schema and stored it in the Repository. You can reuse it in various projects and Job designs.

Click Edit schema to make changes to the schema. If the current schema is of the Repository type, three options are available:

• View schema: choose this option to view the schema only.

• Change to built-in property: choose this option to change the schema to Built-in for local changes.

• Update repository connection: choose this option to change the schema stored in the repository and decide whether to propagate the changes to all the Jobs upon completion.

  If you just want to propagate the changes to the current Job, you can select No upon completion and choose this schema metadata again in the Repository Content window.

Table Name

Specify the name of the table from which the lookup data is extracted.

Advanced key condition expression

Enter the key condition expressions used to determine the items to be read from the table or index.

The result of the query must contain only records that match join key you need to use in tMap. In other words, you must use the schema of the main flow to tMap to construct the SQL statement here in order to load only the matched records into the lookup flow.

This approach ensures that no redundant records are loaded into memory and outputted to the component that follows.

Value mapping

Specify the placeholders for the expression attribute values.

• value: Enter the expression attribute value.

• placeholder: Specify the placeholder for the corresponding value.

For more information, see Expression Attribute Values.

Die on error

Select the check box to stop the execution of the Job when an error occurs.

Advanced properties

Add properties to define extra operations you need tDynamoDBInput to perform when reading data.

This table is present for future evolution of the component and using it requires the high-level knowledge of DynamoDB development. Currently, there are no interesting user configurable properties.

Usage rule

This component is used as a start component and requires an output link.

This component should use a tDynamoDBConfiguration component present in the same Job to connect to a DynamoDB database. You need to drop a tDynamoDBConfiguration component alongside this component and configure the Basic settings of this component to use tDynamoDBConfiguration.

This component, along with the Spark Streaming component Palette it belongs to, appears only when you are creating a Spark Streaming Job.

Note that in this documentation, unless otherwise explicitly stated, a scenario presents only Standard Jobs, that is to say traditional Talend data integration Jobs.

Spark Connection

This connection is effective on a per-Job basis.