The gp_segment_configuration table contains information about mirroring and segment configuration.
|dbid||smallint||The unique identifier of a segment (or master) instance.|
|content||smallint||The content identifier for a segment instance. A primary segment
instance and its corresponding mirror will always have the same content
For a segment the value is from 0-N-1, where N is the number of primary segments in the system.
For the master, the value is always -1.
|role||char||The role that a segment is currently running as. Values are p (primary) or m (mirror).|
|preferred_role||char||The role that a segment was originally assigned at initialization time. Values are p (primary) or m (mirror).|
|mode||char||The synchronization status of a segment with its mirror copy. Values are s (synchronized), c (change logging), or r (resyncing).|
|status||char||The fault status of a segment. Values are u (up) or d (down).|
|port||integer||The TCP port the database server listener process is using.|
|hostname||text||The hostname of a segment host.|
|address||text||The hostname used to access a particular segment on a segment host. This value may be the same as hostname in systems upgraded from 3.x or on systems that do not have per-interface hostnames configured.|
|replication_port||integer||The TCP port the file block replication process is using to keep primary and mirror segments synchronized.|