n8n version: 1.107.4 (happened on a previous version as well)
Running n8n via (Docker, npm, n8n cloud, desktop app): n8n cloud
Describe the problem/error/question
I am running a flow daily for the last 2 months. It creates a report and writes the output to a Supabase Postgre database.
This is the second time in 2 months that I am seeing duplicate database entries a short time apart. The first time I chalked up to a weird occurrence, but now I am seeing it as a worrisome pattern that points to a bugs or issues in n8n cloud that I don’t have the tools/info to debug further.
The workflow:
- Executes daily on a schedule. A JSON report is created.
- You’ll notice that the executions on Aug 26 is nearly twice as long as previous executions… mor on that later…
- A sub-execution is called to update the database. It shows that it executed once.
- The sub-execution however seems to have executed twice, starting at the exact same time.
- The sub execution(s) completed successfully.
- I see duplicate database items based on auto-generated CREATED_AT times in the database
The pattern I see is that both times duplicate entries got created in the database, there were other workflows around the same time that seemed to error out due to n8n cloud backend issues. The first time I got an error that the instance was restarting. This time, a different job complained about an issue with SQLite. The workflow doesn’t use SQLite, so I guess it’s a backend process.
My theory is that somehow my cloud instance is crashing and it’s causing duplicate workflow executions to occur. But I have no idea how to validate this. I am on the 2nd tier Pro plan trying to justify Enterprise to my organization and could really use n8n’s help to understand what is going on.