Introduction
This article describes the different temporary file locations found on FME Flow, their intended purposes, and how long files are preserved for.
1 Engine Temporary Files
Running a workspace on FME Flow submits a job to an engine that will often create temporary files. For example, when processing a large dataset. These temporary files are created by the readers, writers, and transformers in the workspace, and they are the same temporary files that would be created if the workspace were run in FME Form.
In FME Flow, the location of these files on the engine host machine is below:
Windows, when running the engines as a service account:
C:\Users\<service account name>\AppData\Local\Temp\fmeengines\<engine name>
Windows, when running the engines as Local System:
C:\Windows\Temp\fmeengines\<engine name>
Linux:
/tmp/fmeengines/<engine name>
Engine temporary files are usually purged after the engine finishes running the job.
You may want to change the location for engine temporary files to a bigger or faster hard disk. This can be done with the FME_TEMP environment variable. Please see Setting a temporary file location for FME to use via the FME_TEMP environment variable
2 FME Flow System Temporary Files
Actions such as uploading temporary files to a workspace's parameters or running a workspace against a translation service, like the Data Download Service, also create temporary files.
FME Flow system temporary files are stored in the FME Flow system share, which is installed to the location below by default, but can be changed during installation:
Windows:
C:\ProgramData\Safe Software\FMEFlow
Linux:
/opt/fmeflow
In the system share, system temporary files are organized by subfolders for the type of service or task that created them on FME Flow within this subfolder:
<system share>\Resources\System\Temp
System temporary files are cleaned up by system cleanup tasks. By default, most files over a day old are deleted when a system cleanup runs. You can check the max age of files through System Cleanup in the FME Flow web UI. For more details, please see the documentation on System Cleanup.
Please note that since this location resides on the FME Flow system share, it cannot be changed. Please see Can I Change the Location of the FME Flow System Share Directory?
3 User-Defined Temporary Files
When authoring your workflows in FME Form, you can choose to write temporary files by using the FME Flow parameter FME_SHAREDRESOURCE_TEMP in writers. This parameter tells FME Flow to write files to the following location on the FME Flow system share:
<system share>\Resources\Temp
By default, there is no scheduled cleanup. You can choose to create cleanup tasks based on your use case for the \Resources\Temp folder, or your own subfolders within it. To learn more, please see System Cleanup.
Note that this location is not included in FME Flow backups, as it's intended for temporary storage.