Link to the Information Technology Laboratory Website Link to the Information Access Division Website Link to the NIST Website NIST, IAD Banner

Chapter 8. FAQ

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 1: 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.

PROBLEM 2: The duplicator is not present.

SOLUTION: The duplicator executable must be present in the path.

Created on 2008-06-18 by Antoine Fillinger - Last updated on 2008-11-23 by Antoine Fillinger