FME Flow Troubleshooting: Streams

Liz Sanderson
Liz Sanderson
  • Updated

Full Guide: FME Flow Troubleshooting Guide

FME Flow (formerly FME Server) Streams is a dedicated section to run and manage workspaces for real-time stream processing. Many connectors are available through the FME Hub to read from stream data sources like Kafka and RabbitMQ, and some connectors are already included in FME like the JMS and WebSocket Senders/Receivers. Are you encountering issues with FME Flow Streams? Please read below for some common troubleshooting tips, questions and resources.

In 2023, FME Server underwent a name change and is now known as FME Flow. Since this article discusses features present in previous versions of FME, it will refer to both names interchangeably, using the appropriate product name based on the year the feature was introduced. For more information on the rebranding, see our website

Content Overview

Initial Troubleshooting
Common Issues
Additional Resources
Are you still experiencing issues?
Have ideas on how to improve this?

Initial Troubleshooting

  • Is the stream workspace functioning correctly in FME Workbench?
  • Does the FME Flow User have permission to access Streams and the corresponding workspace?
  • Verify that your broker hostname, credentials and/or certificate files are correct.
  • If the stream job isn’t running, make sure that you’ve assigned an Engine and started the stream.
  • Check the stream job log for any errors: <FMEFlowSystemShare>\resources\logs\engine\current\jobs\*.log

Common Issues

“Should I publish stream workspaces to FME Flow with the Data Streaming mode?”

No, stream processing workspaces should be published to FME Flow with only the Job Submitter service. Running a stream workspace is not to be confused with the Data Streaming service which returns writer results back to the requesting client.

“My stream keeps restarting itself, but I’m not seeing any errors.”

First, verify that your workspace has a transformer running in Stream mode. Connectors in Stream mode are designed to run the workspace indefinitely. The workspace will never actually finish as a successful job. If an FME Flow stream job fails, it’s continuously restarted to maintain high uptime.

If you’re using FME Server 2021, you may have encountered a known issue (FMESERVER-16905) that has been resolved for 2022. For this issue, a stream job running into errors would not display the errors in the web interface job log. To see the errors, open the log files through Resources > Logs > Engine > current > jobs > [job_id_group] > [job_id_folder]. If the retries generated many job logs, you may want to delete the parent folder.

“The stream source connector isn’t working in FME Flow.”

If you’re getting an error that says “Python Exception <ModuleNotFoundError>: No module named ‘fmepy_<package component>’”, please verify that the connector package was installed on FME Flow (refer to our packages troubleshooting guide).

“Removing a stopped stream doesn't reassign Engines to the Default queue and they become unavailable.”

This is a known issue for FME Server 2021, and it has been resolved in 2021.0.1 b21313. Please review the known issue article for more details and to see the workaround.

Additional Resources

Documentation: FME Flow Streams
FME and Stream Processing (Landing Page)
How to use the FME Flow Streams Interface

Are you still experiencing issues?

Please consider posting to the FME Community Q&A if you are still experiencing issues that are not addressed in this article. There are also different support channels available. Please provide details on the stream connector you’re using along with any relevant job logs.

Have ideas on how to improve this?

Using a stream data source or message broker that we don’t support yet? Ideas on how we can improve stream processing in FME? You can add ideas or product suggestions to our Ideas Exchange.

Here are some existing ideas:

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