Considerations
If the FME Flow Engines are not visible in the FME Flow Web UI, it may indicate that the job queue service is not running correctly. In the logs, you may see messages similar to:
ERROR RequestHandler-Thread : Failed to connect to Job Queue. Please ensure Job Queue is started.ERROR RequestHandler-Thread : Could not get a resource from the pool
You may also see messages in the fmeprocessmonitorengine.log, such as:
INFORM Thread-11 : Could not read from socket; connection may have been lost
Why This Happens
FME Flow uses an internal queue service to manage communication between components, such as the Engines and the Web UI.
If the queue service fails to start, Engines cannot connect and will not appear in the FME Flow Web UI.
This typically happens when the queue logging directory is missing or cannot be written to:
- The folder <FMEFlowSystemShare>\Resources\logs\queue does not exist
- The log file inside the queue folder cannot be written to
- The account running the FME Flow services does not have sufficient permissions on the folder
When this occurs, the queue process, memurai.exe, will not start. Because the queue process is required for Engines to communicate with FME Flow, the Engines will fail to register and will not appear in the interface.
How to Resolve It
Confirm that the queue logging folder exists and that the FME Flow service account can write to it. Navigate to the following directory on the FME Flow system share: <FMEFlowSystemShare>\Resources\logs
1. Check whether a folder named 'queue' exists. If the folder does not exist, create a new folder named: queue
2. If the folder already exists, delete any existing log file inside the queue folder.
3. Verify permissions on the queue folder and ensure the account running the FME Flow services has Full Control permissions.
4. Restart the FME Flow services. After the services restart and the queue process starts successfully, the Engines should reconnect and appear in the FME Flow Web UI.
Additional Notes
If the queue folder repeatedly disappears or permissions keep resetting, review any automated cleanup scripts or security policies that may be modifying the contents of the Resources\logs directory.
Additional Resources
- FME Flow Documentation: Engine Architecture
- FME Flow Documentation: System Share and Resource Folders