Introduction

An application can run an IBM® Transformation Extender map on a web server either synchronously or asynchronously. Use synchronous processing to run a map that must complete before it returns a response to the calling application. When you run a map asynchronously, the API returns URLs that an application can use to check the status of a long-running map and to retrieve output data and audit and trace logs when the map completes.

Running a map asynchronously requires a Redis server in addition to the web server. See the product release notes for details.

The servlet that implements the ITX REST APIs can run as a separate process from the web server process, in fenced run mode. Fenced mode ensures that an ITX failure does not affect the web server. Fenced mode is required to run a map asynchronously. In unfenced run mode, the servlet runs within the web server. Run maps in unfenced mode only for demos or during testing; do not use unfenced mode in production.

The HTTP request that invokes a map can pass data to one or more of the map's input cards. The HTTP response can return one or more map outputs. The API call can specify an adapter override that causes the map to receive input from an adapter or write output data to an adapter.

In addition, ITX provides a REST API that you can use to catalog maps and generate Swagger documentation for them. An application can run a cataloged map without specifying the URL of the map location or the cards to override, simplifying the web service call. This approach enables maps to be exposed as REST API endpoints without the need for the caller of the API to be aware of any ITX specifics.

The product release notes describe the prerequisites and required configuration to use the REST API and the tutorial.