...
The preferred way to startup the nodes in cluster is to start one node at a time, ensure the node is up and functional, and then move on to the next node in the cluster. Do not attempt to start all nodes of the cluster at the same time or concurrently.
Upgrading
A small amount of downtime is required for smooth upgrade of OpenSpecimen. When upgrading, bring down all the nodes. Upgrade one node at a time, ensure the node is up and functional, and then move on to upgrade the next node in the cluster. Do not attempt to run multiple versions of OpenSpecimen against the same database schema. The Otherwise, the behaviour is unspecified.
...