Establishing a client session over a TCP/IP connection

Configure a TCPIPClientInput node to open a session over an existing TCP/IP connection, before any data is sent or received.

About this task

You can use the Open terminal of the TCPIPClientInput node to enable processing to start when a connection is opened, rather than when data first arrives. If the Open terminal is connected, an empty message is sent to the Open terminal when a connection is created. This message has the local environment set to the connection details.

The connection associated with the message is reserved from the general connection pool until propagation to the Open terminal has finished. However, the connection can be accessed using the connectionId specified in the local environment. Each connection that is created is sent to the Open terminal, including any connections that are created mid-flow by a TCPIPClientReceive node or TCPIPClientOutput node.

If the Open terminal is not attached, open events are automatically made available in the connection pool.

The following steps show how to configure a message flow that contains a TCPIPClientInput node, with the Open terminal configured to start processing when a TCP/IP connection is created.

Procedure

Create a message flow containing a TCPIPClientInput node, a Compute node, and a TCPIPClientOutput node.
For information about how to do this, see Creating a message flow Creating a message flow.
Connect the Open terminal of the TCPIPClientInput node to the In terminal of the Compute node.
Connect the Out terminal of the TCPIPClientInput node to the In terminal of the TCPIPClientOutput node.
On the TCPIPClientInput node, set the Connection details property (on the Basic tab) to 14143.

On the Compute node, set the ESQL property (on the Basic tab) to:

CREATE COMPUTE MODULE test_Compute1
	CREATE FUNCTION Main() RETURNS BOOLEAN
	BEGIN
		-- CALL CopyMessageHeaders();
		CALL CopyEntireMessage();
		RETURN TRUE;
	END;

	CREATE PROCEDURE CopyMessageHeaders() BEGIN
		DECLARE I INTEGER 1;
		DECLARE J INTEGER;
		SET J = CARDINALITY(InputRoot.*[]);
		WHILE I < J DO
			SET OutputRoot.*[I] = InputRoot.*[I];
			SET I = I + 1;
		END WHILE;
	END;

	CREATE PROCEDURE CopyEntireMessage() BEGIN
		SET OutputRoot = InputRoot;
	END;
END MODULE;

Set the following properties of the TCPIPClientOutput node:
1. On the Basic tab, set the Connection details property to 14143.
2. On the Request tab, set the ID location property to LocalEnvironment/TCPIP/Input/ConnectionDetails/Id.
Save the message flow.