For ProcessRobot -  High Availability, we recommend Redis Sentinels using the best practices to set up and configure the nodes. The minimum recommended deployment would be 3 Redis nodes all spread out in different availability zones

  • 1 Master 
  • 2 Replicas 

The reason behind this is that if there is one Sentinel left, the procedure of voting will NOT take place. We don't store data for a long time and in case of a Redis node failure, the data are repopulated. 

Also, check the official Redis Sentinel Documentation