G
gus bjorklund
Guest
I’ve written about this many times in the past. Here is another rendition. Connecting a 4GL client to an OpenEdge database via TCP/IP takes place as follows: 0: the 4GL client sends a connect request to the login broker specified by a -S service name or port number. The database login broker should have been set up to be listening for connect requests on this port. 1: when the login broker (which could be the primary or a secondary, depending on configuration) receives the connect request, it will find a suitable server process to handle the connection. Suitable means either a server with an unused client slot or if none are available, a new server process will be started (depending on configuration). Server assignment could be round-robin or fill-existing-first or some variation. This depends on min clients per server and max clients per server settings. 2: when the server has been chosen, the server is notified of the client connect request and it chooses a port on which to listen for a login request from the client. 3: the server tells the login broker which port it wants to use. the broker makes a note of this and other relevant information. 4: the login broker sends a message back to the client with the port information and then closes the connection. Once this has happened, all further communication occurs between the client and its assigned server. 5: the client send a login request to the server. 6: the server assigns a database connection slot on behalf of the client and establishes the database connection. 7. the server sends a login accepted back to the client.=
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