Sun GlassFish Mobility Platform 1.1 Developer's Guide for Enterprise Connectors

Deployment Flexibility

The JAX-RS API provides more flexibility in how you deploy an Enterprise Connector.

If you install Sun GlassFish Mobility Platform and you decide to use the ECBO API, you must remain with your original installation, whether it is a single-tier or a two-tier installation. If you use the ECBO API in a two-tier installation, communication between the Gateway on the first tier and the Enterprise Connector on the second tier requires the Web Services Connector endpoint that is installed as part of the two-tier installation. If you use the ECBO API in a single-tier installation, the Gateway and the Enterprise Connector communicate directly using ECBO API calls.

If you decide to use the JAX-RS API for your Enterprise Connector, however, you gain some flexibility in how you deploy your Enterprise Connector. A JAX-RS Enterprise Connector does not use the Web Services Connector endpoint. Instead, communication between the Gateway and the Enterprise Connector takes place over HTTP/S. This means that you can deploy the Enterprise Connector (and a Sun JCA Adapter, if it uses one) on any system with a GlassFish installation. If you used a single-tier installation, you can deploy the Enterprise Connector locally (on the same system where you installed the Gateway) or remotely (on a different system from the one where you installed the Gateway).

It is easier to develop a JAX-RS Enterprise Connector initially, because you can easily redeploy the Enterprise Connector on the fly, without having to restart the server. Redeploying an ECBO Enterprise Connector, on the other hand, usually requires you to restart the domain when you deploy a new version.