### repmgrd startup log example

Source: https://www.repmgr.org/docs/current/repmgr.html

Example log output when repmgrd starts on a standby node. Shows connection status and monitoring initiation.

```log
[2019-08-15 07:14:42] [NOTICE] repmgrd (repmgrd 5.0) starting up
[2019-08-15 07:14:42] [INFO] connecting to database "host=node2 dbname=repmgr user=repmgr connect_timeout=2"
INFO:  set_repmgrd_pid(): provided pidfile is /var/run/repmgr/repmgrd-12.pid
[2019-08-15 07:14:42] [NOTICE] starting monitoring of node "node2" (ID: 2)
[2019-08-15 07:14:42] [INFO] monitoring connection to upstream node "node1" (ID: 1)
```

--------------------------------

### Install PostgreSQL build prerequisites on Debian/Ubuntu

Source: https://www.repmgr.org/docs/current/repmgr.html

Install the prerequisites for building PostgreSQL on Debian or Ubuntu systems using apt-get.

```bash
sudo apt-get update
       sudo apt-get build-dep postgresql-9.6
```

--------------------------------

### Install repmgr from source

Source: https://www.repmgr.org/docs/current/repmgr.html

Configure and install repmgr from the source code. Ensure pg_config for the target PostgreSQL version is in your PATH.

```bash
./configure && make install
```

--------------------------------

### repmgr Password File Example (with wildcards)

Source: https://www.repmgr.org/docs/current/repmgr.html

Simplified example of a ~/.pgpass file using wildcards for hosts, ports, and databases when specific restrictions are not required.

```text
*:*:*:repmgr:foo
*:*:*:postgres:foo
```

--------------------------------

### repmgr Password File Example (with superuser)

Source: https://www.repmgr.org/docs/current/repmgr.html

Example of a ~/.pgpass file including entries for a superuser ('postgres') when using the -S/--superuser option.

```text
node1:5432:repmgr:repmgr:foo
node1:5432:repmgr:postgres:foo
node1:5432:replication:repluser:foo
node2:5432:repmgr:repmgr:foo
node2:5432:repmgr:postgres:foo
node2:5432:replication:repluser:foo
node3:5432:repmgr:repmgr:foo
node3:5432:repmgr:postgres:foo
node3:5432:replication:repluser:foo
```

--------------------------------

### Install PostgreSQL build prerequisites on RHEL/CentOS

Source: https://www.repmgr.org/docs/current/repmgr.html

Install the prerequisites for building PostgreSQL on RHEL or CentOS systems using yum.

```bash
sudo yum check-update
       sudo yum groupinstall "Development Tools"
       sudo yum install yum-utils openjade docbook-dtds docbook-style-dsssl docbook-style-xsl
       sudo yum-builddep postgresql96
```

--------------------------------

### Barman Server Configuration Example

Source: https://www.repmgr.org/docs/current/repmgr.html

An example of a Barman server configuration section in its configuration file, referenced by 'barman_server' in repmgr.conf.

```ini
[pg]
description = "Main cluster"
...
```

--------------------------------

### Install repmgr Snapshot RPM Repository (as root)

Source: https://www.repmgr.org/docs/current/repmgr.html

Execute this command as the root user to install the EDB public snapshot repository for repmgr 9.6. This allows for the installation of snapshot packages.

```bash
curl https://dl.enterprisedb.com/default/snapshot/get/9.6/rpm | bash
```

--------------------------------

### repmgr Password File Example (repmgr user)

Source: https://www.repmgr.org/docs/current/repmgr.html

Example of a ~/.pgpass file for a 3-node cluster using the 'repmgr' database user for both metadata access and replication.

```text
node1:5432:repmgr:repmgr:foo
node1:5432:replication:repmgr:foo
node2:5432:repmgr:repmgr:foo
node2:5432:replication:repmgr:foo
node3:5432:repmgr:repmgr:foo
node3:5432:replication:repmgr:foo
```

--------------------------------

### Promote Command Example for repmgrd

Source: https://www.repmgr.org/docs/current/repmgr.html

Example of setting the `promote_command` in `repmgr.conf`. This command is executed by repmgrd when a node needs to be promoted to primary. Ensure `--log-to-file` is used for proper logging.

```ini
promote_command='/usr/bin/repmgr standby promote -f /etc/repmgr.conf --log-to-file'
```

--------------------------------

### repmgr daemon start

Source: https://www.repmgr.org/docs/current/repmgr.html

Starts the repmgrd service on the local node. By default, it waits up to 15 seconds for confirmation, which can be adjusted or disabled.

```APIDOC
## repmgr daemon start

### Description
Starts the repmgrd service on the local node. By default, repmgr will wait for up to 15 seconds to confirm that repmgrd started. This behaviour can be overridden by specifying a different value using the `--wait` option, or disabled altogether with the `--no-wait` option.

### Important
The `repmgr.conf` parameter `repmgrd_service_start_command` must be set for `repmgr daemon start` to work.

### Method
Not specified (CLI command)

### Endpoint
Not applicable (CLI command)

### Parameters
#### Options
- `--wait <seconds>` - Specifies the time to wait for repmgrd to start (default: 15 seconds).
- `--no-wait` - Disables waiting for repmgrd to start.

### Request Example
```bash
$ repmgr daemon start
```

### Response
#### Success Response
- repmgrd service started successfully on the local node.

#### Error Response
- Specific error codes are not detailed in the provided text, but failures may occur if `repmgrd_service_start_command` is not configured or if the service fails to start.

```

--------------------------------

### pg_rewind execution example

Source: https://www.repmgr.org/docs/current/repmgr.html

This example shows the expected output from repmgr when pg_rewind execution is required. It highlights the timeline and WAL location details.

```text
NOTICE: pg_rewind execution required for this node to attach to rejoin target node 1
DETAIL: rejoin target server's timeline 3 forked off current database system timeline 2 before current recovery point 0/7019C10
```

--------------------------------

### repmgr Configuration File Example

Source: https://www.repmgr.org/docs/current/repmgr.html

This is a minimal example of a repmgr.conf file. It must contain at least node_id, node_name, conninfo, and data_directory. Do not store this file within the PostgreSQL data directory.

```ini
node_id=1
node_name='node1'
conninfo='host=node1 user=repmgr dbname=repmgr connect_timeout=2'
data_directory='/var/lib/postgresql/data'
```

--------------------------------

### Example repmgr.conf File

Source: https://www.repmgr.org/docs/current/repmgr.html

A sample repmgr.conf file demonstrating basic configuration parameters like node ID, name, connection info, and data directory.

```shell
# repmgr.conf

node_id=1
node_name= node1
conninfo ='host=node1 dbname=repmgr user=repmgr connect_timeout=2'
data_directory = '/var/lib/pgsql/12/data'
```

--------------------------------

### Install repmgr Snapshot RPM Repository (with sudo)

Source: https://www.repmgr.org/docs/current/repmgr.html

Run this command as a normal user with sudo access to install the EDB public snapshot repository for repmgr 9.6. This method is an alternative to running as root directly.

```bash
curl https://dl.enterprisedb.com/default/snapshot/get/9.6/rpm | sudo bash
```

--------------------------------

### Example Status Log Line

Source: https://www.repmgr.org/docs/current/repmgr.html

This is an example of a status log line emitted by repmgrd at a configured interval, showing its current state.

```text
[2018-07-12 00:47:32] [INFO] monitoring connection to upstream node "node1" (ID: 1)
```

--------------------------------

### Start repmgrd Daemon

Source: https://www.repmgr.org/docs/current/repmgr.html

Starts the repmgrd service on the local node. The repmgr.conf parameter 'repmgrd_service_start_command' must be set for this command to function. By default, it waits up to 15 seconds for confirmation.

```bash
repmgr daemon start
```

--------------------------------

### repmgr Password File Example (dedicated replication user)

Source: https://www.repmgr.org/docs/current/repmgr.html

Example of a ~/.pgpass file for a 3-node cluster using a dedicated replication user ('repluser') for replication connections.

```text
node1:5432:repmgr:repmgr:foo
node1:5432:replication:repluser:foo
node2:5432:repmgr:repmgr:foo
node2:5432:replication:repluser:foo
node3:5432:repmgr:repmgr:foo
node3:5432:replication:repluser:foo
```

--------------------------------

### Install repmgr14 Package

Source: https://www.repmgr.org/docs/current/repmgr.html

Installs the repmgr14 package using DNF. This command assumes the EDB repository has already been configured and is accessible.

```bash
sudo dnf install repmgr14
```

--------------------------------

### Configure repmgrd Service Commands

Source: https://www.repmgr.org/docs/current/repmgr.html

Set the commands to start and stop the repmgrd service. This is required if using 'repmgr daemon start' and 'repmgr daemon stop'.

```shell
repmgrd_service_start_command='sudo systemctl repmgr12 start'
repmgrd_service_stop_command='sudo systemctl repmgr12 stop'
```

--------------------------------

### Start repmgrd Manually

Source: https://www.repmgr.org/docs/current/repmgr.html

Use this command to start the repmgrd daemon manually. Ensure the configuration file and PID file paths are correct for your environment.

```bash
repmgrd -f /etc/repmgr.conf --pid-file /tmp/repmgrd.pid
```

--------------------------------

### Register Primary Server with repmgr

Source: https://www.repmgr.org/docs/current/repmgr.html

Use this command to register the primary node with repmgr. This installs the repmgr extension and metadata, and creates a record for the primary server.

```bash
$ repmgr -f /etc/repmgr.conf primary register
INFO: connecting to primary database...
NOTICE: attempting to install extension "repmgr"
NOTICE: "repmgr" extension successfully installed
NOTICE: primary node record (id: 1) registered
```

--------------------------------

### Install Specific repmgr Package Version (dnf)

Source: https://www.repmgr.org/docs/current/repmgr.html

After listing available versions, use this command to install a precise version of repmgr. Ensure the version string matches one of the available packages.

```bash
[root@localhost ~]# dnf install repmgr10-5.3.0-1.el8
```

--------------------------------

### List Available repmgr Package Versions (dnf)

Source: https://www.repmgr.org/docs/current/repmgr.html

Use this command to see all available versions of a repmgr package before installation. This helps in identifying the exact version string needed for specific installations.

```bash
[root@localhost ~]# dnf --showduplicates list repmgr10
```

--------------------------------

### Example repmgr Snapshot Package Name

Source: https://www.repmgr.org/docs/current/repmgr.html

This is an example of how a repmgr snapshot package name is formatted. It includes the version, snapshot build number, and git commit hash.

```text
repmgr96-4.1.1-0.0git320.g5113ab0.1.el7.x86_64.rpm
```

--------------------------------

### repmgr node status command example

Source: https://www.repmgr.org/docs/current/repmgr.html

Displays an overview of a node's basic information and replication status. This command must be run on the local node.

```bash
$ repmgr -f /etc/repmgr.conf node status
Node "node1":
    PostgreSQL version: 10beta1
    Total data size: 30 MB
    Conninfo: host=node1 dbname=repmgr user=repmgr connect_timeout=2
    Role: primary
    WAL archiving: off
    Archive command: (none)
    Replication connections: 2 (of maximal 10)
    Replication slots: 0 (of maximal 10)
    Replication lag: n/a
```

--------------------------------

### Standby Follow Command Example

Source: https://www.repmgr.org/docs/current/repmgr.html

Example of using the 'repmgr standby follow' command to attach a standby node to a new upstream primary. This command restarts the PostgreSQL server after reconfiguring the standby.

```bash
$ repmgr -f /etc/repmgr.conf standby follow
      INFO: setting node 3's primary to node 2
      NOTICE: restarting server using "pg_ctl -l /var/log/postgres/startup.log -w -D '/var/lib/postgres/data' restart"
      waiting for server to shut down........ done
      server stopped
      waiting for server to start.... done
      server started
      NOTICE: STANDBY FOLLOW successful
      DETAIL: node 3 is now attached to node 2
```

--------------------------------

### repmgr node service with --superuser and --checkpoint

Source: https://www.repmgr.org/docs/current/repmgr.html

Example of using the --superuser and --checkpoint options with repmgr node service. This allows repmgr to execute CHECKPOINT.

```bash
repmgr node service --checkpoint -S postgres
```

--------------------------------

### Search for Available repmgr Packages

Source: https://www.repmgr.org/docs/current/repmgr.html

Lists all available repmgr packages in the configured repositories. This command is useful for discovering package names before installation.

```bash
dnf search repmgr
```

--------------------------------

### repmgr standby switchover with --superuser

Source: https://www.repmgr.org/docs/current/repmgr.html

Example of using the --superuser option with repmgr standby switchover. This allows repmgr to execute the CHECKPOINT command.

```bash
repmgr standby switchover -S postgres
```

--------------------------------

### Install repmgr using APT (Debian/Ubuntu)

Source: https://www.repmgr.org/docs/current/repmgr.html

After configuring the EDB APT repository, use this command to install the repmgr package suitable for your PostgreSQL version. For older PostgreSQL versions (9.6 and earlier), the package name format differs.

```bash
sudo apt-get install postgresql-11-repmgr
```

--------------------------------

### repmgr standby clone with --superuser

Source: https://www.repmgr.org/docs/current/repmgr.html

Example of using the --superuser option with repmgr standby clone. This is necessary when copying configuration files outside the data directory with --copy-external-config-files.

```bash
repmgr standby clone --copy-external-config-files -S postgres
```

--------------------------------

### repmgr node check with --superuser

Source: https://www.repmgr.org/docs/current/repmgr.html

Example of using the --superuser option with repmgr node check. This is required for executing repmgr node check --data-directory-config.

```bash
repmgr node check --data-directory-config -S postgres
```

--------------------------------

### Configuring Systemd Service Commands (CentOS 7)

Source: https://www.repmgr.org/docs/current/repmgr.html

Example configuration for repmgr.conf using systemd commands on CentOS 7. These commands require passwordless sudo access for the postgres user.

```config
service_start_command   = 'sudo systemctl start postgresql-9.6'
service_stop_command    = 'sudo systemctl stop postgresql-9.6'
service_restart_command = 'sudo systemctl restart postgresql-9.6'
service_reload_command  = 'sudo systemctl reload postgresql-9.6'
```

--------------------------------

### Create repmgr extension

Source: https://www.repmgr.org/docs/current/repmgr.html

Execute this command in the database of an existing repmgr installation to move and convert objects to the standard 'repmgr' schema. Ensure only one schema matches 'repmgr_%' in the database.

```sql
CREATE EXTENSION repmgr FROM unpackaged
```

--------------------------------

### Build HTML Documentation

Source: https://www.repmgr.org/docs/current/repmgr.html

Execute this command to generate HTML documentation files. The output will be in the doc/html subdirectory.

```bash
./configure && make doc
```

--------------------------------

### Build PDF Documentation

Source: https://www.repmgr.org/docs/current/repmgr.html

Run this command to generate the documentation in PDF format (A4 size) after building the main repmgr source.

```bash
./configure && make doc-repmgr-A4.pdf
```

--------------------------------

### Build Single HTML File Documentation

Source: https://www.repmgr.org/docs/current/repmgr.html

Use this command to create a single HTML file for the documentation after building the main repmgr source.

```bash
./configure && make doc-repmgr.html
```

--------------------------------

### Add apt.postgresql.org repository

Source: https://www.repmgr.org/docs/current/repmgr.html

Add the apt.postgresql.org repository to your sources.list and ensure the source repository is enabled.

```bash
deb https://apt.postgresql.org/pub/repos/apt/ stretch-pgdg main
deb-src https://apt.postgresql.org/pub/repos/apt/ stretch-pgdg main
```

--------------------------------

### Install repmgr on CentOS 6

Source: https://www.repmgr.org/docs/current/repmgr.html

Use this command to install the repmgr package on CentOS 6 systems. Replace '96' with your specific PostgreSQL major version.

```bash
yum install repmgr96
```

--------------------------------

### Install repmgr Package

Source: https://www.repmgr.org/docs/current/repmgr.html

Use this command to install the repmgr package for PostgreSQL 11 on Debian systems. Ensure you replace '11' with your specific PostgreSQL major version.

```bash
apt-get install postgresql-11-repmgr
```

--------------------------------

### Install repmgr on CentOS 7

Source: https://www.repmgr.org/docs/current/repmgr.html

Use this command to install the repmgr package on CentOS 7 systems. Ensure you replace '11' with your specific PostgreSQL major version.

```bash
yum install repmgr11
```

--------------------------------

### repmgr follow_command Example

Source: https://www.repmgr.org/docs/current/repmgr.html

Specifies the command to execute when a node follows a new primary. Ensure the full path is used for user-defined scripts. The %n placeholder is replaced by the new primary's node ID. The --log-to-file option directs output to repmgrd's log destination.

```bash
follow_command='/usr/bin/repmgr standby follow -f /etc/repmgr.conf --log-to-file --upstream-node-id=%n'
```

--------------------------------

### repmgrd Log: Initializing and Connecting Nodes

Source: https://www.repmgr.org/docs/current/repmgr.html

Shows typical repmgrd log output when it starts up on the primary node and child nodes begin to connect. This is before the minimum required child nodes are connected.

```log
[2019-04-24 15:25:33] [INFO] monitoring primary node "node1" (ID: 1) in normal state
[2019-04-24 15:25:35] [NOTICE] new node "node2" (ID: 2) has connected
[2019-04-24 15:25:35] [NOTICE] 1 (of 1) child nodes are connected, but at least 2 child nodes required
[2019-04-24 15:25:35] [INFO] no child nodes have detached since repmgrd startup
(...)
[2019-04-24 15:25:44] [NOTICE] new node "node3" (ID: 3) has connected
[2019-04-24 15:25:46] [INFO] monitoring primary node "node1" (ID: 1) in normal state
(...)
```

--------------------------------

### Record repmgrd startup event

Source: https://www.repmgr.org/docs/current/repmgr.html

Records a 'repmgrd_start' event for a specific node in the cluster. Useful for auditing and debugging.

```bash
$ repmgr -f /etc/repmgr.conf cluster event --event=repmgrd_start
     Node ID | Name  | Event         | OK | Timestamp           | Details
---------+-------+---------------+----+---------------------+--------------------------------------------------------
     3       | node3 | repmgrd_start | t  | 2019-08-15 07:14:42 | monitoring connection to upstream node "node1" (ID: 1)
     2       | node2 | repmgrd_start | t  | 2019-08-15 07:14:41 | monitoring connection to upstream node "node1" (ID: 1)
     1       | node1 | repmgrd_start | t  | 2019-08-15 07:14:39 | monitoring cluster primary "node1" (ID: 1)
```

--------------------------------

### Start PostgreSQL in Single-User Mode for pg_rewind

Source: https://www.repmgr.org/docs/current/repmgr.html

This snippet demonstrates how to start a PostgreSQL instance in single-user mode to perform recovery, making it suitable for pg_rewind. Ensure `standby.signal` or `recovery.conf` is removed beforehand.

```bash
rm -f /var/lib/pgsql/data/recovery.conf
postgres --single -D /var/lib/pgsql/data/ < /dev/null
```

--------------------------------

### pg_rewind no rewind required example

Source: https://www.repmgr.org/docs/current/repmgr.html

This example shows the output from pg_rewind when it determines that no rewind action is necessary, even if repmgr indicated it was required. This can occur in specific corner-case bugs in older PostgreSQL versions.

```text
pg_rewind: servers diverged at WAL location 0/7015540 on timeline 2
pg_rewind: no rewind required
```

--------------------------------

### Install a specific old repmgr package version

Source: https://www.repmgr.org/docs/current/repmgr.html

Install a specific version of a repmgr package on RHEL/CentOS systems by providing the package name and version. The version can be found using `yum --showduplicates list`.

```bash
yum install {package_name}-{version}
```

```bash
yum install repmgr96-4.0.6-1.rhel6
```

--------------------------------

### Get repmgr Cluster Status in CSV Format

Source: https://www.repmgr.org/docs/current/repmgr.html

Outputs the replication cluster's status in a simple CSV format, suitable for parsing by scripts. Use this to get a machine-readable overview of your cluster's health.

```bash
$ repmgr -f /etc/repmgr.conf service status --csv
1,node1,primary,1,1,5722,1,100,-1,default
2,node2,standby,1,0,-1,1,100,1,default
3,node3,standby,1,1,5779,1,100,1,default
```

--------------------------------

### PostgreSQL replication termination log example

Source: https://www.repmgr.org/docs/current/repmgr.html

This example shows log entries from a PostgreSQL standby server indicating that replication was terminated by the primary server due to timeline divergence, often seen when pg_rewind incorrectly reports no action is needed.

```log
[2020-09-07 15:01:41 UTC]    LOG:  00000: replication terminated by primary server
[2020-09-07 15:01:41 UTC]    DETAIL:  End of WAL reached on timeline 2 at 0/7015540.
[2020-09-07 15:01:41 UTC]    LOG:  00000: new timeline 3 forked off current database system timeline 2 before current recovery point 0/7019C10
```

--------------------------------

### Configuring pg_ctlcluster Service Commands (Debian/Ubuntu)

Source: https://www.repmgr.org/docs/current/repmgr.html

Example configuration for repmgr.conf using pg_ctlcluster for Debian/Ubuntu systems. It is recommended to use 'sudo pg_ctlcluster' to ensure systemd has an accurate view of the PostgreSQL application state.

```config
service_start_command   = 'sudo pg_ctlcluster 9.6 main start'
service_stop_command    = 'sudo pg_ctlcluster 9.6 main stop'
service_restart_command = 'sudo pg_ctlcluster 9.6 main restart'
service_reload_command  = 'sudo pg_ctlcluster 9.6 main reload'
```

--------------------------------

### Update repmgr extension

Source: https://www.repmgr.org/docs/current/repmgr.html

Run this SQL command in the database where repmgr is installed on the primary node after a major version upgrade.

```sql
ALTER EXTENSION repmgr UPDATE
```

--------------------------------

### Get Raw repmgr Version Number

Source: https://www.repmgr.org/docs/current/repmgr.html

Use the --version-number option for scripts that require a parseable representation of the repmgr version.

```bash
repmgr --version-number
```