pg_stat_replication

The pg_stat_replication view contains metadata of the walsender process that is used for Greenplum Database master mirroring.

column	type	description
`procpid`	integer	Process ID of WAL sender backend process.
`usesysid`	integer	User system ID that runs the WAL sender backend process
`usename`	name	User name that runs WAL sender backend process.
`application_name`	oid	Client application name.
`client_addr`	name	Client IP address.
`client_port`	integer	Client port number.
`backend_start`	timestamp	Operation start timestamp.
`state`	text	WAL sender state. The value can be: `startup` `backup` `catchup` `streaming`
`sent_location`	text	WAL sender xlog record sent location.
`write_location`	text	WAL receiver xlog record write location.
`flush_location`	text	WAL receiver xlog record flush location.
`replay_location`	text	Standby xlog record replay location.
`sync_priority`	text	Priorty. the value is `1`.
`sync_state`	text	WAL sender syncronization state. The value is `sync`.

Parent topic: System Catalogs Definitions