gp_master_mirroring
The gp_master_mirroring table contains state information about the standby master host and its associated write-ahead log (WAL) replication process. If this synchronization process (gpsyncagent) fails on the standby master, it may not always be noticeable to users of the system. This catalog is a place where HAWQ administrators can check to see if the standby master is current and fully synchronized.
Table 1. pg_catalog.gp_master_mirroring
| column | type | references | description |
|---|---|---|---|
summary_state |
text | The current state of the log replication process between the master and standby master - logs are either ‘Synchronized’ or ‘Not Synchronized’ | |
detail_state |
text | If not synchronized, this column will have information about the cause of the error. | |
log_time |
timestamp with time zone | This contains the timestamp of the last time a master mirroring change occurred. For example, the timestamp when the value of summary_state changed from “Synchronized” to “Not Synchronized”. If no changes occur with regards to the standby master (it stays synchronized), the timestamp is not updated. |
|
error_message |
text | If not synchronized, this column will have the error message from the failed synchronization attempt. |