Custom External Adapters

The external adapter framework provides a mechanism to create and add adapters that are not included in the set provided by Event Stream Processor.

External adapters can be added in the field and provide all necessary information to allow the Studio and Server to manage and interact with an external datasource or sink. These custom adapters are simply datasource and sink applications that are built with the Pub/Sub API. After an adapter configuration file (cnxml) is installed, an external adapter can be used in the Studio in the same way as built-in adapters.

• External Adapter Configuration File
  The framework defines the structure of the external adapter configuration file (cnxml) file that contains the adapter properties.
• External Adapter Properties
  See examples in $ESP_HOME/lib/connections/PLUGIN_TEMPLATE.cnxmlfor a sample cnxml file that may be copied and customized. It has all possible internal parameters embedded in it, and has comment blocks indicating their usage.
• External Adapter Commands
  External adapter commands fall into two categories: those that run on the same host as Studio, and those that run on the same host as the Server.
• User-Defined Parameters and Parameter Substitution
  Internal parameters and any number of user-defined parameters can be created in the cnxml file.
• Auto-Generated Parameter Files
  The basic external adapter framework, when started, writes its set of parameters (system and user-defined) to a parameter file.
• configFilename Parameter
  The configFilename parameter enables you to specify user-editable configuration files in the Studio.
• Custom External Parameter Datatypes
  The adapter.xsd schema supports several datatypes for user-defined parameters.
• Creating Custom External Adapters
  General steps for using SDKs to build custom adapters.