Data Loss After Restarting All Leaders and Followers in Redis Cluster

[captainpro-eng]

We are currently running a Redis cluster with the following versions:
Redis Operator Helm Chart: 18.0.5
Redis Operator Image: 18.0.1
Redis Image: 7.0.12

We have tested multiple Redis failover scenarios, and in most cases, the cluster state is marked as "OK" and data is preserved after restarts. However, we encountered a scenario where restarting all the masters and slaves results in the cluster state being "OK", but all data is lost. Below is a summary of the test cases:

Tested Scenarios:

• Restarted 3 leaders only: After all leaders came back up, the cluster state became "OK" and all data was preserved.

• Restarted all the leaders : After all leaders came back up, the cluster state became "OK" and all data was secure.

• Restarted all the followers : After all followers came back up, the cluster state became "OK" and all data was secure.

• Restarted 3 leaders and 3 followers : After all leaders and followers came back up, the cluster state became "OK" and all data was secure.

• Restarted all the leaders and all the followers: After all masters and slaves came back up, the cluster state was "OK", but all data was lost.