This question refers to the Directory modified trigger but the same information applies to all the file modified triggers, i.e. S3 Bucket, Dropbox, FTP.
Consideration
The Directory Modified trigger in Automations sends an event for each file or folder change. If multiple files are added at once, each one will trigger a separate event. This can lead to multiple executions of the same downstream action or workspace.
Users often expect that a single event would be triggered for batch file additions, but this is not currently supported.
Why This Happens
The Directory Modified trigger is not designed to detect grouped or batched changes. It treats each file or folder event (create, modify, delete) individually. As a result:
- Every file uploaded triggers a separate automation event.
- There is no mechanism within the trigger to consolidate multiple events into one.
This behavior aligns with how other event-based triggers work in FME Flow Automations.
How to Resolve This
Option 1. Schedule Trigger
If you would like a workspace (or other downstream action) to only run once but to process multiple file changes, one approach would be to swap the trigger to use a Schedule trigger set to run at a regular interval (similar to the polling interval in the Directory watch).
In the workspace, you will need to build in some logic to fetch only the files that have changed in this interval. You can achieve this by using the Directory and File Path Names reader to get a list of all files in the Directory and set the Retriever File Properties parameter to yes. Using a Tester transformer, you can check if the path_created_date or path_modified_date attribute is within the last schedule interval - this can be calculated using date/time functions.
Option 2. Zip File
Request your users to compress the files into one zip file before uploading them to the directory so that it triggers a single event. Then, have the workspace read in the zip file to be processed in the workspace.