The dispatcher type to be used is selected on the step of FIX Antenna build. In other words, there are no any FIX Engine parameters to configure it on fly.
To determine what dispatcher type is currently used by FIX Antenna, the user needs to look at logs of the "Engine" category. When FIX Antenna is started, one of the following records appears with "INFO" severity:
At the moment FIX Antenna is always built with USE_SELECT_DISPATCHER dispatcher type.
Below is the example of how it looks like in logs:
[INFO] 20160725-11:59:29.999  [Engine] - USE_SELECT_DISPATCHER = ON
USE_IOCP_DISPATCHER and USE_EPOLL_DISPATCHER were experimental feature which were disabled since 2.10.16
Dispatcher.XXX parameters from Dispatcher section are not used at the moment.