Displays information about each registered node in the replication cluster. This command polls each registered server and shows its role (primary / standby / bdr) and status. It polls each server directly and can be run on any node in the cluster; this is also useful when analyzing connectivity from a particular node.
Node availability is tested by connecting from the node where repmgr cluster show is executed, and does not necessarily imply the node is down. See repmgr cluster matrix and repmgr cluster crosscheck to get better overviews of connections between nodes.
This command requires either a valid repmgr.conf file or a database connection string to one of the registered nodes; no additional arguments are needed.
To show database connection errors when polling nodes, run the command in --verbose mode.
$ repmgr -f /etc/repmgr.conf cluster show
ID | Name | Role | Status | Upstream | Location | Priority | Connection string
----+-------+---------+-----------+----------+----------+----------+-----------------------------------------
1 | node1 | primary | * running | | default | 100 | host=db_node1 dbname=repmgr user=repmgr
2 | node2 | standby | running | node1 | default | 100 | host=db_node2 dbname=repmgr user=repmgr
3 | node3 | standby | running | node1 | default | 100 | host=db_node3 dbname=repmgr user=repmgr
The column Role shows the expected server role according to the repmgr metadata.
Status shows whether the server is running or unreachable. If the node has an unexpected role not reflected in the repmgr metadata, e.g. a node was manually promoted to primary, this will be highlighted with an exclamation mark. If a connection to the node cannot be made, this will be highlighted with a question mark. Note that the node will only be shown as ? unreachable if a connection is not possible at network level; if the PostgreSQL instance on the node is pingable but not accepting connections, it will be shown as ? running.
In the following example, executed on node3, node1 is not reachable at network level and assumed to be down; node2 has been promoted to primary (but node3 is not attached to it, and its metadata has not yet been updated); node4 is running but rejecting connections (from node3 at least).
ID | Name | Role | Status | Upstream | Location | Priority | Connection string
----+-------+---------+----------------------+----------+----------+----------+-----------------------------------------
1 | node1 | primary | ? unreachable | | default | 100 | host=db_node1 dbname=repmgr user=repmgr
2 | node2 | standby | ! running as primary | node1 | default | 100 | host=db_node2 dbname=repmgr user=repmgr
3 | node3 | standby | running | node1 | default | 100 | host=db_node3 dbname=repmgr user=repmgr
4 | node4 | standby | ? running | node1 | default | 100 | host=db_node4 dbname=repmgr user=repmgr
WARNING: following issues were detected
- unable to connect to node "node1" (ID: 1)
- node "node1" (ID: 1) is registered as an active primary but is unreachable
- node "node2" (ID: 2) is registered as standby but running as primary
- unable to connect to node "node4" (ID: 4)
HINT: execute with --verbose option to see connection error messages
To diagnose connection issues, execute repmgr cluster show with the --verbose option; this will display the error message for each failed connection attempt.
Tip: Use repmgr cluster matrix and repmgr cluster crosscheck to diagnose connection issues across the whole replication cluster.
repmgr cluster show accepts an optional parameter --csv, which outputs the replication cluster's status in a simple CSV format, suitable for parsing by scripts, e.g.:
$ repmgr -f /etc/repmgr.conf cluster show --csv
1,-1,-1
2,0,0
3,0,1
The columns have following meanings:
Suppress display of the conninfo column.
Suppress warnings about connection issues.
Display the full text of any database connection error messages
One of the following exit codes will be emitted by repmgr cluster show:
No issues were detected.
An issue was encountered while attempting to retrieve repmgr metadata.
repmgr was unable to connect to the local PostgreSQL instance.
One or more issues were detected with the replication configuration, e.g. a node was not in its expected state.