In this section, we provide some solutions to common problems that can arise when using the data flow system.

SYMPTOM: Server launched but other servers do no appear in its list.

PROBLEM: Server cannot connect to other hosts for some reason.

SOLUTION: Turn the firewall off and try again. Check if name lookup works properly (ping the host).

SYMPTOM: Communication does only work one way (provider on one machine, consumer on the other machine works, but not the other way around)

PROBLEM: Probably the host can not be found because the host lookup and the machine name are different.

SOLUTION: Look at the server log and try to ping the machine. If this works just adjust the machines host name.

SYMPTOM: Provider running, Consumer launched but no data is coming in and the application seems to be stuck or hanging.

PROBLEM: Probably the proper flow-descriptions do not match.

SOLUTION: Check if the flows connect properly. This can be done by using discovery capability of the Control Center, taking a look at the client connections. Or by checking carefully for proper flow names and flow connection IDs (they have to match in both client nodes).

SYMPTOM: Provider running, Consumer cannot connect to the flow for a longer period of time. Which Looks like:

#> ./your_client
[CLI  ANNOUNCE 15:27:36.336939] [ Log_Manager::init ] Logging to Syslog Off
[CLI  ANNOUNCE 15:27:36.337662] [ Log_Manager::init ] Log Propagation Off
[CLI  ERROR    15:27:36.345504] [ FlowImpl_ACE::open_duplicator ] Error Connect for flow
'beamspace_activity:Flow_Feature_SFM'.. trying again... 
[CLI  ERROR    15:27:36.845887] [ FlowImpl_ACE::open_duplicator ] Error Connect for flow
'beamspace_activity:Flow_Feature_SFM'.. trying again... 
[CLI  ERROR    15:27:37.346182] [ FlowImpl_ACE::open_duplicator ] Error Connect for flow
'beamspace_activity:Flow_Feature_SFM'.. trying again... 
[CLI  ERROR    15:27:37.846532] [ FlowImpl_ACE::open_duplicator ] Error Connect for flow
'beamspace_activity:Flow_Feature_SFM'.. trying again... 
[CLI  ERROR    15:27:38.346837] [ FlowImpl_ACE::open_duplicator ] Error Connect for flow
'beamspace_activity:Flow_Feature_SFM'.. trying again... 

PROBLEM: Socket cannot be accessed, probably because of system rights.

SOLUTION: All clients on the same host have to be launched using the same 'user' which launched the server (sf2d), in order to avoid right problems.