Data Change Notification Interface

Data change notification (DCN) provides an HTTP interface by which enterprise information system (EIS) changes can be immediately propagated to Unwired Server.

Sybase Unwired Platform provides the gson-1.4.jar library you use to construct a DCN URL located in the <UnwiredPlatform_InstallDir>\Servers\UnwiredServer\lib\ext directory. All DCN commands support both GET and POST methods. The EIS developer creates and sends a DCN to Unwired Server through HTTP GET or POST operations. The portion of the DCN command parameters that come after http://host:8000/dcn/DCNServlet, can all be in POST; any var=name can be in either the URL (GET) or in the POST. The HTTP POST method is more secure than HTTP GET methods; therefore, Sybase recommends that you include the authenticate.password parameter in the POST method, as well as any sensitive data provided for attributes and parameters.

Note: Enter the HTTP request on a single line.

You must be familiar with the EIS data source from which the DCN is issued. You can create and send DCNs that are based on:

Database triggers
EIS system events
External integration processes

You can use DCN with payload to instruct Unwired Server to refresh data:

DCN with payload – calls only the two direct cache-affecting operations (:upsert or :delete), which always exist for an MBO, and are not related to user-defined MBO operations.
- :upsert – the message must contain name/value pairs for every required attribute, and the name must exactly match the MBO attribute name.
- :delete – provide only the name/value pairs for the primary key column(s).
These operations respectively insert or update, or delete a row in the CDB. Calling either of these operations does not trigger any other refresh action:
1. Some event initiates the DCN request (a database trigger for example).
2. The Unwired Server cache is updated directly from the EIS. The actual data (payload) is applied to the cache, through either an :upsert (update or insert) or a :delete operation.
3. Unwired Server returns a DCN status message to the requester.