Working with LoopBack connectors

IBM® Integration Bus provides a LoopBackRequest node, which enables you to issue synchronous requests to backend data sources by using LoopBack® connectors such as MongoDB, Cloudant®, or PostgreSQL.

About this task

You can use a LoopBackRequest node in a message flow to access or create records through a LoopBack connector. First, you must install your chosen connector to work with IBM Integration Bus, and then configure the data source for the connector. You can then specify the security credentials that are required to access it. The following topics describe the steps involved in completing those tasks:

  1. Installing the LoopBack connector
  2. Configuring the data source and models for your LoopBack connector
  3. Specifying security credentials for connecting to a secured data source
When you have completed these tasks, you can use a LoopBackRequest node in a message flow to create, retrieve, update, and delete records, as described in the following topics:

The LoopBackRequest node operations are synchronous and non-transactional, which means that, if a message flow fails and rolls back after the LoopBackRequest node, the operation on the data source will still complete.

The LoopBackRequest node supports a number of local environment message tree variables, which you can use to dynamically alter the values that are set in the node properties. For information about defining these environment variables, see Using local environment variables with LoopBackRequest nodes.

For more information about configuring and using the LoopBackRequest node in a message flow, see LoopBackRequest node.

When you pass data to a data source through a LoopBackRequest node (when you create or update a record, for example), you must use the JSON domain for providing data in the input message. Replies to a LoopBack request are provided as JSON domain messages.

If you want to use a Mapping node to create the input or process the output data, you must use one of the supported options for defining a message model for the LoopBack connector JSON data. For more information, see Creating or transforming a JSON output message by using a message map.

For help with diagnostics, check the user trace and the LoopBack activity log, which contains information that is created when a LoopBackRequest node issues a request. For information about the type of information that is included, see LoopBack Activity log.