I have a question about the Mina/Netty TCP connector in Camel. Can Mina/Netty handle bi-directional comms through Camel, or do we need to handle this type of interface externally? We have embedded devices (button/light combo) that will consume TCP messages to light a device and initiate messages to indicate button press events. In other words, the device is the server, but will also spontaneously generate event messages back to the client/ESB. Both sides (server/device,client/ESB) expect ACKs for messages. So in essence, it is a 2-way communication using 1 TCP connection, initiated by ESB.
Unfortunately, Camel Netty and Mina doesn’t have the capability to support 2-way asynchronous (https://issues.apache.org/jira/browse/CAMEL-2624 - It’s still open ticket rom 2010, 2012 + this is the duplicated ticket with some more context: https://issues.apache.org/jira/browse/CAMEL-1075 ) What we have tried so far: 1. synchronous channel (before realize the limitation above): This will always require our ESB-EndPoint to initiate the conversation, good to receive ACK, but not allowing device to send Event message at will. 2. asynchronous channel: (http://camel.apache.org/async.html ) With async model, we can send request, do something else and let the async callback to process the reply. However, we still have a 1-1 relationship between request and reply, and so in order to allow device to “initiate” the Event message, ESB-Endpoint will need to send more “no-op requests” to device-Endpoint, to catch for ACK and Event message. This solution is not beautiful (quite hacking), and will not work if there’s no “no-op operation” (e.g. device will ACK on all messages sent). 3. Look at examples in these 2 books: “Camel in Actions” ( https://dl.dropboxusercontent.com/u/3786274/Camel%20In%20Action.pdf ) and “Apache Camel Developer’s Cookbook” ( https://dl.dropboxusercontent.com/u/3786274/Apache%20Camel%20Developer%20Cookbook.pdf ) but not much light on the issue we are facing. Any help? --carl
