RTI® DDS Spy (rtiddsspy) is invaluable when debugging thorny problems with DDS applications. It is a command-line tool that receives all DDS communication. rtiddsspy:
Enables inspection of data that applications are publishing, on any DDS domain.
Can subscribe to select DDS Topics and display data samples it receives to the terminal.
rtiddsspy enables you to further narrow down the problem space by filtering data by Topic, setting Quality of Service (QoS) profiles, and monitoring specific Data-Distribution Service™ (DDS) domains, along with many other options.