tSQSQueueList - 6.3

Talend Open Studio for Big Data Components Reference Guide

EnrichVersion
6.3
EnrichProdName
Talend Open Studio for Big Data
task
Data Governance
Data Quality and Preparation
Design and Development
EnrichPlatform
Talend Studio

tSQSQueueList iterates and lists the URL of the Amazon SQS (Simple Queue Service) queues in a specified region.

tSQSQueueList properties in Standard Jobs

These properties are used to configure tSQSQueueList.

The tSQSQueueList component belongs to the Cloud/Amazon/SQS family.

Basic settings

Use an existing connection

Select this check box and in the Component List click the relevant connection component to reuse the connection details you already defined.

Access Key and Secret Key

Specify the access keys (the access key ID in the Access Key field and the secret access key in the Secret Key field) required to access the Amazon Web Services. For more information about AWS access keys, see Access keys (access key ID and secret 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.

Inherit credentials from AWS role

Select this check box to leverage the instance profile credentials. These credentials can be used on Amazon EC2 instances, and are delivered through the Amazon EC2 metadata service. To use this option, your Job must be running within Amazon EC2 or other services that can leverage IAM Roles for access to resources. For more information, see Using an IAM Role to Grant Permissions to Applications Running on Amazon EC2 Instances.

Assume role

Select this check box and specify the values for the following parameters used to create a new assumed role session.

  • Role ARN: the Amazon Resource Name (ARN) of the role to assume.

  • Role session name: an identifier for the assumed role session.

  • Session duration (minutes): the duration (in minutes) for which we want to have the assumed role session to be active.

For more information about assuming roles, see AssumeRole.

Region

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

Advanced settings

Config client

Select this check box and in the table displayed specify the client configuration parameters. Click the button below the table to add as many rows as needed, each row for a client configuration parameter, and set the value of the following attributes for each parameter:

  • Client Parameter: click the cell and select a parameter from the drop-down list.

  • Value: enter the value for the corresponding parameter.

STS Endpoint

Select this check box and in the field displayed, specify the AWS Security Token Service endpoint where session credentials are retrieved from.

This check box is available only when the Assume role check box is selected.

tStatCatcher Statistics

Select this check box to gather the Job processing metadata at the Job level as well as at each component level.

Global variables

CURRENT_QUEUE_NAME

The URL of the queue being processed. This is a Flow variable and it returns a string.

NB_QUEUE

The number of queues processed. This is an After variable and it returns an integer.

ERROR_MESSAGE

The error message generated by the component when an error occurs. This is an After variable and it returns a string.

Usage

Usage Rule

This component can be used as a standalone component or as a start component of a Job or Subjob.

Listing Amazon SQS queues in an AWS region

Here's an example of using Talend components to iterate and list the URLs of all Amazon SQS (Simple Queue Service) queues in an AWS region.

Creating a Job for listing Amazon SQS queues

Create a Job to open a connection to access Amazon SQS, then iterate and list the URLs of all Amazon SQS queues in a specified region, finally display the total number of the queues in the region.

Prerequisites: You must create several Amazon SQS queues in an AWS region in order to replicate this scenario. In this example, four queues talend, talend-dev, talend-doc and talend-qa have been created in the Asia Pacific (Tokyo) region as shown in below figure.

  1. Create a new Job and add a tSQSConnection component, a tSQSQueueList component, a tIterateToFlow component, a tLogRow component, and a tJava component by typing their names in the design workspace or dropping them from the Palette.

  2. Link the tSQSQueueList component to the tIterateToFlow component using a Row > Iterate connection.

  3. Link the tIterateToFlow component to the tLogRow component using a Row > Main connection.

  4. Link the tSQSConnection component to the tSQSQueueList component using a Trigger > OnSubjobOk connection.

  5. Link the tSQSQueueList component to the tJava component using a Trigger > OnSubjobOk connection.

Opening a connection to access Amazon SQS

Configure the tSQSConnection component to open a connection to access Amazon SQS.

  1. Double-click the tSQSConnection component to open its Basic settings view.

  2. In the Access Key and Secret Key fields, specify the authentication information required to access Amazon SQS.

  3. Select an AWS region available for Amazon SQS from the Region drop-down list. In this example, it is Asia Pacific (Tokyo).

Listing all Amazon SQS queues in an AWS region

Configure the tSQSQueueList component, the tIterateToFlow component, the tLogRow component, and the tJava component to list the URLs of all Amazon SQS queues in an AWS region and display the total number of the queues in the region on the console of Talend Studio.

  1. Double-click the tSQSQueueList component to open its Basic settings view.

  2. Specify the connection details required to access Amazon SQS. In this example, select the Use an existing connection check box and from the Component List drop-down list displayed, select the connection component to reuse its connection details you have already defined.

  3. Double-click the tIterateToFlow component to open its Basic settings view.

  4. Click the button next to Edit schema to open the schema dialog box.

  5. Click the button to add one String type column CurrentQueueURL that will hold the URLs of the queues to be listed. When done, click OK to close the dialog box.

  6. In the Mapping table, set the value for the CurrentQueueURL column. In this example, the value is set to ((String)globalMap.get("tSQSQueueList_1_CURRENT_QUEUE_NAME")), which is the value of the global variable CURRENT_QUEUE_NAME for the tSQSQueueList component.

    Note that you can fill the value by pressing Ctrl + Space to access the global variables list and then selecting tSQSQueueList_1_CURRENT_QUEUE_NAME from the list.

  7. Double-click the tLogRow component to open its Basic settings view, and then select Table (print values in cells of a table) in the Mode area for better readability of the result.

  8. Double-click the tJava component to open its Basic settings view.

  9. In the Code field, enter the following code to display the total number of the queues in the region.

    System.out.println("The number of queues: " + ((Integer)globalMap.get("tSQSQueueList_1_NB_QUEUE")));

Executing the Job to list Amazon SQS queues

After setting up the Job and configuring the components used in the Job for listing Amazon SQS queues, you can then execute the Job and verify the Job execution result.

  1. Press Ctrl + S to save the Job.

  2. Press F6 to execute the Job.