PostgreSQL pg_autoctl / pg_atuo_failover commands

 

configuration related commands:

-bash-4.2$ pg_autoctl config check
16:25:57 30701 INFO  Postgres setup for PGDATA "/var/lib/pgsql/14/data" is ok, running with PID 5432 and port 3193
16:25:57 30701 INFO  Connection to local Postgres ok, using "port=5432 dbname=pg_auto_failover host=/run/postgresql user=autoctl_node"
pgdata:                /var/lib/pgsql/14/data
pg_ctl:                /usr/pgsql-14/bin/pg_ctl
pg_version:            "14.11" (1411)
pghost:                /run/postgresql
pgport:                5432
proxyport:             0
pid:                   3193
is in recovery:        no
Control cluster state: in production
Control Version:       1300
Catalog Version:       202107181
System Identifier:     7349600518161216196
Latest checkpoint LSN: 0/3EBDB48
Postmaster status:     ready
 

-bash-4.2$ pg_autoctl config get
[pg_autoctl]
role = monitor
hostname = admin01.localdomain

[postgresql]
pgdata = /var/lib/pgsql/14/data
pg_ctl = /usr/pgsql-14/bin/pg_ctl
username = autoctl_node
dbname = pg_auto_failover
host = /run/postgresql
port = 5432
listen_addresses = *
auth_method = trust

[ssl]
sslmode = require
active = 1
cert_file = /var/lib/pgsql/14/data/server.crt
key_file = /var/lib/pgsql/14/data/server.key
 

to set/modify the configuration, use set parameter.


-bash-4.2$ pg_autoctl config set
16:28:31 32762 ERROR Two arguments are expected, found 0
-bash-4.2$ pg_autoctl config set --help
pg_autoctl config set: Set the value of a given pg_autoctl configuration variable
usage: pg_autoctl config set  [ --pgdata ] [ --json ] section.option [ value ]

  --pgdata      path to data directory

-bash-4.2$ pg_autoctl show settings
  Context |    Name |                   Setting | Value                                                       
----------+---------+---------------------------+-------------------------------------------------------------
formation | default |      number_sync_standbys | 0                                                           
  primary |  node_1 | synchronous_standby_names | 'ANY 1 (pgautofailover_standby_3, pgautofailover_standby_2)'
     node |  node_1 |        candidate priority | 50                                                          
     node |  node_2 |        candidate priority | 50                                                          
     node |  node_3 |        candidate priority | 70                                                          
     node |  node_1 |        replication quorum | true                                                        
     node |  node_2 |        replication quorum | true                                                        
     node |  node_3 |        replication quorum | true 



Replication verfication commands:


 -bash-4.2$ pg_autoctl show uri
        Type |    Name | Connection String
-------------+---------+-------------------------------
     monitor | monitor | postgres://autoctl_node@admin01.localdomain:5432/pg_auto_failover?sslmode=require
   formation | default | postgres://rep01.localdomain:5432,rep02.localdomain:5432,master01.localdomain:5432/autodb?target_session_attrs=read-write&sslmode=require



-bash-4.2$ pg_autoctl show events
                    Event Time |   Node |       Current State |      Assigned State | Comment
-------------------------------+--------+---------------------+---------------------+-----------
 2024-03-25 16:12:25.804573+00 |    0/2 |           secondary |          catchingup | Node node 2 "node_2" (rep01.localdomain:5432) is marked as healthy by the monitor
 2024-03-25 16:12:26.612818+00 |    0/2 |          catchingup |          catchingup | New state is reported by node 2 "node_2" (rep01.localdomain:5432): "catchingup"
 2024-03-25 16:12:26.612818+00 |    0/2 |          catchingup |           secondary | Setting goal state of node 2 "node_2" (rep01.localdomain:5432) to secondary after it caught up.
 2024-03-25 16:12:26.778657+00 |    0/2 |           secondary |           secondary | New state is reported by node 2 "node_2" (rep01.localdomain:5432): "secondary"
 2024-03-25 16:12:26.847366+00 |    0/1 |        wait_primary |             primary | Setting goal state of node 1 "node_1" (master01.localdomain:5432) to primary now that we have 1 healthy  secondary nodes in the quorum.
 2024-03-25 16:12:27.014049+00 |    0/1 |             primary |             primary | New state is reported by node 1 "node_1" (master01.localdomain:5432): "primary"
 2024-03-25 16:12:50.808192+00 |    0/3 |           secondary |          catchingup | Node node 3 "node_3" (rep02.localdomain:5432) is marked as healthy by the monitor
 2024-03-25 16:12:51.572948+00 |    0/3 |          catchingup |          catchingup | New state is reported by node 3 "node_3" (rep02.localdomain:5432): "catchingup"
 2024-03-25 16:12:51.572948+00 |    0/3 |          catchingup |           secondary | Setting goal state of node 3 "node_3" (rep02.localdomain:5432) to secondary after it caught up.
 2024-03-25 16:12:51.716066+00 |    0/3 |           secondary |           secondary | New state is reported by node 3 "node_3" (rep02.localdomain:5432): "secondary"



-bash-4.2$ pg_autoctl show state
  Name |  Node |                 Host:Port |       TLI: LSN |   Connection |      Reported State |      Assigned State
-------+-------+---------------------------+----------------+--------------+---------------------+--------------------
node_1 |     1 | master01.localdomain:5432 |   6: 0/9000520 |   read-write |             primary |             primary
node_2 |     2 |    rep01.localdomain:5432 |   6: 0/9000520 |    read-only |           secondary |           secondary
node_3 |     3 |    rep02.localdomain:5432 |   6: 0/9000000 |    read-only |           secondary |           secondary



-bash-4.2$ pg_autoctl show standby-names
'ANY 1 (pgautofailover_standby_3, pgautofailover_standby_2)'


-bash-4.2$ pg_autoctl show file
   File | Path
--------+----------------
 Config | /var/lib/pgsql/.config/pg_autoctl/var/lib/pgsql/14/data/pg_autoctl.cfg
    Pid | /tmp/pg_autoctl/var/lib/pgsql/14/data/pg_autoctl.pid

 

 

Switchover commands:


-bash-4.2$ pg_autoctl perform switchover
16:35:04 6225 INFO  Waiting 60 secs for a notification with state "primary" in formation "default" and group 0
16:35:04 6225 INFO  Listening monitor notifications about state changes in formation "default" and group 0
16:35:04 6225 INFO  Following table displays times when notifications are received
    Time |   Name |  Node |                 Host:Port |       Current State |      Assigned State
---------+--------+-------+---------------------------+---------------------+--------------------
16:35:04 | node_1 |     1 | master01.localdomain:5432 |             primary |            draining
16:35:04 | node_1 |     1 | master01.localdomain:5432 |            draining |            draining
16:35:04 | node_1 |     1 | master01.localdomain:5432 |            draining |          report_lsn
16:35:04 | node_2 |     2 |    rep01.localdomain:5432 |           secondary |          report_lsn
16:35:04 | node_3 |     3 |    rep02.localdomain:5432 |           secondary |          report_lsn
16:35:05 | node_2 |     2 |    rep01.localdomain:5432 |          report_lsn |          report_lsn
16:35:05 | node_3 |     3 |    rep02.localdomain:5432 |          report_lsn |          report_lsn
16:35:05 | node_1 |     1 | master01.localdomain:5432 |          report_lsn |          report_lsn
16:35:05 | node_3 |     3 |    rep02.localdomain:5432 |          report_lsn |   prepare_promotion
16:35:05 | node_3 |     3 |    rep02.localdomain:5432 |   prepare_promotion |   prepare_promotion
16:35:05 | node_3 |     3 |    rep02.localdomain:5432 |   prepare_promotion |        wait_primary
16:35:06 | node_2 |     2 |    rep01.localdomain:5432 |          report_lsn |      join_secondary
16:35:06 | node_1 |     1 | master01.localdomain:5432 |          report_lsn |      join_secondary
16:35:06 | node_2 |     2 |    rep01.localdomain:5432 |      join_secondary |      join_secondary
16:35:06 | node_1 |     1 | master01.localdomain:5432 |      join_secondary |      join_secondary
16:35:07 | node_3 |     3 |    rep02.localdomain:5432 |        wait_primary |        wait_primary
16:35:07 | node_1 |     1 | master01.localdomain:5432 |      join_secondary |           secondary
16:35:07 | node_2 |     2 |    rep01.localdomain:5432 |      join_secondary |           secondary
16:35:07 | node_2 |     2 |    rep01.localdomain:5432 |           secondary |           secondary
16:35:07 | node_3 |     3 |    rep02.localdomain:5432 |        wait_primary |             primary
16:35:07 | node_3 |     3 |    rep02.localdomain:5432 |             primary |             primary


To watch the live replication status:

bash-4.2$ pg_autoctl watch


Other operational commands:


-bash-4.2$ pg_autoctl watch


-bash-4.2$ pg_autoctl status
16:50:08 18772 INFO  pg_autoctl is running with pid 3180
16:50:08 18772 INFO  Postgres is serving PGDATA "/var/lib/pgsql/14/data" on port 5432 with pid 3193


-bash-4.2$ pg_autoctl reload


-bash-4.2$ pg_autoctl version
pg_autoctl version 1.6.3
pg_autoctl extension version 1.6
compiled with PostgreSQL 14.0 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44), 64-bit
compatible with Postgres 10, 11, 12, 13, and 14


-bash-4.2$ pg_autoctl stop


-bash-4.2$ pg_autoctl status
16:50:56 19266 INFO  pg_autoctl is not running at "/var/lib/pgsql/14/data"


-bash-4.2$ pg_autoctl show state
16:51:03 19274 ERROR Failed to open file "/var/lib/pgsql/14/data/postmaster.pid": No such file or directory
16:51:03 19274 INFO  Is PostgreSQL at "/var/lib/pgsql/14/data" up and running?
16:51:03 19274 ERROR Failed to get Postgres pid, see above for details
16:51:03 19274 FATAL Failed to discover PostgreSQL setup, please fix previous errors.
16:51:03 19274 FATAL Failed to read configuration file "/var/lib/pgsql/.config/pg_autoctl/var/lib/pgsql/14/data/pg_autoctl.cfg"


-bash-4.2$ nohup pg_autoctl run &
[1] 19288
-bash-4.2$ nohup: ignoring input and appending output to ‘nohup.out’

-bash-4.2$ pg_autoctl show state
  Name |  Node |                 Host:Port |       TLI: LSN |   Connection |      Reported State |      Assigned State
-------+-------+---------------------------+----------------+--------------+---------------------+--------------------
node_1 |     1 | master01.localdomain:5432 |   7: 0/9000810 |    read-only |           secondary |           secondary
node_2 |     2 |    rep01.localdomain:5432 |   7: 0/9000810 |    read-only |           secondary |           secondary
node_3 |     3 |    rep02.localdomain:5432 |   7: 0/9000810 |   read-write |             primary |             primary

                                                



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