Building Distributed
Applications
Using the Progress AppServer
Specifying the Type of Remote Request
The type of remote request (synchronous or asynchronous) is determined by the 4GL procedure that initiates it, using options on the RUN statement. The AppServer can handle both types of requests in the same AppServer session and over the same client connection.
You can initiate as many asynchronous requests as you want at any point during client execution. You can also mix synchronous and asynchronous requests in the same application. The only constraint is that you can only initiate a synchronous request if there are no pending (incomplete) asynchronous requests over the same AppServer connection. Progress also provides a mechanism for you to check the status of asynchronous requests on a connection.
NOTE: As suggested earlier, the Application Server process that executes a request does not know if the request is synchronous or asynchronous. The Application Broker manages each request on behalf of the client, and dispatches the request for execution according to the AppServer operating mode (state-reset, state-aware, or stateless). Consequently, the client can execute synchronous and asynchronous requests without regard to the AppServer operating mode.
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