Cluster member startup

As each member of the cluster starts, a number of events occur:

During startup, each PolicyCenter server runs a checksum on its own configuration. The server then compares its checksum with the configuration checksum stored in the database. If the startup server determines that the two configurations are not compatible, it does not start.
As each PolicyCenter server joins the cluster, it updates a membership table in the PolicyCenter database. All cluster members periodically poll this table to determine cluster membership.
During a rolling upgrade of the individual server members in the cluster, the startup server verifies that it is running either the source (original) or target (new) configuration. If the server detects any other configuration, it does not start.