Is our FreeFileSync appropriate for our usecase?

[briandant]

We have several FTP sites, from which we need to fetch files, change their names, and send them to another FTP location. This would all happen in a batch job, run on a schedule. Is FreeFileSync a good program for our use case?

Some other details:

1) We need to run these batch jobs on a schedule
2) We have many sites with many different credentials
3) We need to modify the filenames each time they are picked up
4) We need to ensure that a file is picked up and moved once and only once
a) in other words, the file may still be in the source location, but we would want it to be ignored the next time, since it was already synced

[Plerry]

1) and 2) Should be no problem
3) not clear what you mean. As long as files are in the left- or right-base-location or any of its subfolders, they are subject to synchronization (as long as meeting at least one of the Include Filter rules, and none of the Exclude Filter rules)
4) synchronization involves copying files, so they exist both left and right, not moving files (e.g. left-to-right)
4.a) The problem with FTP is that often file-dates are not preserved when copying files (the copied-over file gets the timestamp of the moment it is copied over). This creates a difference in timestamp of a file between sync-source and -target. When using a Compare criterion of File Time and Size and a Mirror sync variant, this would cause FFS to re-sync the file.
If you use the Update sync variant you are OK, but that may not be your preferred action.
So, if possible, use a method/protocol that preserves file dates (some/most SFTP's do, just like SMB)

If that is not possible, and you prefer a Mirror-like sync, you can still use FFS, but then you best define a Custom sync variant:
• For the Category "Item exists on left side only" select the Action "Copy new item to right" (This is the same as for the Mirror and Update sync variant)
• For the Category "Left side is newer" select the Action "Update right item" (This is the same as for the Mirror and Update sync variant)
• For the Category "Conflict/item can not be categorized" select the Action "Leave as an unresolved conflict" (This is the same as for the Update sync variant) or select the Action ""Update right item" (This is the same as for the Mirror sync variant), depending on preference.
• For the Category "Right side is newer" select the Action "Do nothing" (This is the same as for the Update sync variant, but different from the Mirror sync variant). This should be OK, as apparently you copied the file over after the source-side file-date of the file. This fails if you manually restored an earlier version of the file to your left-side location, e.g. from a backup.
• For the Category "Item exists on right side only" select the Action "Delete right item" (This is the same as for the Mirror sync variant, but different from the Update sync variant)

The prime difference rests in the fourth bullet, "Right side is newer".

[briandant]

@plerry: thank you! This is so helpful for us. I'm reviewing your response in conjunction with digging further into the docs.