Problem

 
When a temporary IP-based user's session expires, the cleanup job (runs every 15 minutes) deletes the user and all tasks where they are PM - without checking whether any of those tasks are still being processed. If an import is in progress when this happens, the task's materialized view is dropped while a worker is still writing to it. This produces "Base table or view not found" errors in the log and the import fails halfway through. From the user's side, the translation simply disappears from their history.

Solution

 
In the IP authentication plugin's GC handler, before removing a task check whether any worker for that task is still in a non-terminal state (anything other than done/defunct) in
Zf_worker. If yes, skip the task. If any task was skipped, also skip the user deletion - the next GC tick (15 min later) will retry, and once the workers finish naturally, the user and their tasks will be cleaned up as before.