Data loss from collection

Yesterday, I left my local machine running, connected to my MongoDB cluster.

The web app has a CRUD and I’ve been creating test projects{name, description, etc} in a collection called “projects”. I also have test issues{title, description, etc} in a collection called “issues”. This morning, when I refreshed the web page, the projects list is empty and in the cloud.MongoDB.com Admin the collection is empty.

My last entry yesterday from the Project Activity Feed was:
User performed a Data Explorer read-only operation
Username: xxxxxx.com
Host ID: xxxx
Operation: schemaAdvisor

Database: easy-notes

Collection: projects

Changed by xxxxx.com fromxxx.xxx.xx.xx 06/19/24 - 11:51:45 AM

This morning I only did READ access to the cluster like these:
User performed a Data Explorer read-only operation
Username: xxxxx.com
Host ID: xxxxxx
Operation: schemaAdvisor

Database: easy-notes

Collection: projects

Changed by xxxx.com from xxxxxxxx 06/20/24 - 06:43:22 AM

I’ve had a look at the Project Activity Feed and with Clusters selected the last entries are about a month ago:
Host has restarted
[address.mongodb.net](Cloud: MongoDB Cloud 06/05/24 - 08:36:07 PM
Host is now secondary
address.mongodb.net in atlas-xxxxxshard-0 06/05/24 - 08:31:47 PM

Any idea how or why the data was lost and how to prevent future losses (the current data is test data only, so the loss is not the issue, but when the system goes live data loss will be catastrophic!) ? Else, I’ll have to abandon MongoDB if the data is not safe?

I’m not sure this is the issue, but I connected a rogue app that I was testing to the same collection. The problem is that I cannot see a record in the project Activity Feed of any deletions, so there is that mystery…

The issue is certainly on your side. Data is safe in MongoDB. If data gets deleted, it is configured to be deleted with a ttl index or someone or some application deleted it.