To workaround the issue and prevent any possible data loss upgrade using the following procedure.
1. open the Sentinel web interface and go to storage | scalable storage
Note: Make note of the current Kafka port being used.
2. Change the Kafka port number to something else and save
Note: The will temporarily cause incoming data to be cached on the CM (collector manager).
3. Upgrade per SSDM upgrade instructions in the Sentinel install guide.
4. Change the Kafka port back to the original port number