Common Errors and their Meanings


errno -111: Connection Refused

This error occurs when DAQInterface sends a transition command to an artdaq process.
It indicates that an exception occurred while processing the command, and it was not caught by error-handling code with artdaq.

artdaq System

<Process>: Back-pressure condition: All Shared Memory buffers have been full for <time>!

This message indicates that the process' companion art process(es) are not keeping up.
  • If the time resets every few seconds, this is indicative of disk-writing or processing taking too long. In this case, adding additional art processes or distributing disk-writing may help.
  • If, however, the time climbs monotonically to a large number, it usually indicates a dead art process. You should check the art process log and/or the launch_attempt log file to see if the art process encountered a fatal error that was not reported to the Message Viewer.

Stop request received by RequestReceiver, but no requests have ever been received.
Did not receive acks from all senders after resending table <N> times during the table_update_interval. Check the status of the senders!

These issue can be caused by multicast messages not getting from their sources to their destinations. The requestSender and requestReceiver applications can be used to debug these issues.