Configure the controller card in order to access different servers running on it — either by the data cards, or by the controller card itself. Make sure that the controller card has a larger amount of flash memory than the data cards do. This flash memory contains all the binaries, data and configuration files that the applications on the data cards access as if they were on a local storage device.
Call the following API to communicate with the mqueue server by any application:
mq_open("/net/cc0/dev/mqueue/app_q", ....)
A simple variation of the above command requires that you run the following command during initialization:
$ ln -s /net/cc0/dev/mqueue /mq
Then all applications, whether they're running on the data cards or on the controller card, can call:
mq_open("/mq/app_q", ....)
Similarly, applications can even utilize the TCP/IP stack running on the controller card.