---
stage: Enablement
group: Database
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
type: reference
---
# Working with the bundled PgBouncer service **(PREMIUM SELF)**
[PgBouncer](http://www.pgbouncer.org/) is used to seamlessly migrate database
connections between servers in a failover scenario. Additionally, it can be used
in a non-fault-tolerant setup to pool connections, speeding up response time
while reducing resource usage.
GitLab Premium includes a bundled version of PgBouncer that can be managed
through `/etc/gitlab/gitlab.rb`.
## PgBouncer as part of a fault-tolerant GitLab installation
This content has been moved to a [new location](replication_and_failover.md#configuring-the-pgbouncer-node).
## PgBouncer as part of a non-fault-tolerant GitLab installation
1. Generate PGBOUNCER_USER_PASSWORD_HASH with the command `gitlab-ctl pg-password-md5 pgbouncer`
1. Generate SQL_USER_PASSWORD_HASH with the command `gitlab-ctl pg-password-md5 gitlab`. Enter the plaintext SQL_USER_PASSWORD later.
1. On your database node, ensure the following is set in your `/etc/gitlab/gitlab.rb`
```ruby
postgresql['pgbouncer_user_password'] = 'PGBOUNCER_USER_PASSWORD_HASH'
postgresql['sql_user_password'] = 'SQL_USER_PASSWORD_HASH'
postgresql['listen_address'] = 'XX.XX.XX.Y' # Where XX.XX.XX.Y is the ip address on the node postgresql should listen on
postgresql['md5_auth_cidr_addresses'] = %w(AA.AA.AA.B/32) # Where AA.AA.AA.B is the IP address of the pgbouncer node
```
1. Run `gitlab-ctl reconfigure`
NOTE:
If the database was already running, it needs to be restarted after reconfigure by running `gitlab-ctl restart postgresql`.
1. On the node you are running PgBouncer on, make sure the following is set in `/etc/gitlab/gitlab.rb`
```ruby
pgbouncer['enable'] = true
pgbouncer['databases'] = {
gitlabhq_production: {
host: 'DATABASE_HOST',
user: 'pgbouncer',
password: 'PGBOUNCER_USER_PASSWORD_HASH'
}
}
```
1. Run `gitlab-ctl reconfigure`
1. On the node running Puma, make sure the following is set in `/etc/gitlab/gitlab.rb`
```ruby
gitlab_rails['db_host'] = 'PGBOUNCER_HOST'
gitlab_rails['db_port'] = '6432'
gitlab_rails['db_password'] = 'SQL_USER_PASSWORD'
```
1. Run `gitlab-ctl reconfigure`
1. At this point, your instance should connect to the database through PgBouncer. If you are having issues, see the [Troubleshooting](#troubleshooting) section
## Backups
Do not backup or restore GitLab through a PgBouncer connection: it causes a GitLab outage.
[Read more about this and how to reconfigure backups](../../raketasks/backup_restore.md#backup-and-restore-for-installations-using-pgbouncer).
## Enable Monitoring
> [Introduced](https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/3786) in GitLab 12.0.
If you enable Monitoring, it must be enabled on **all** PgBouncer servers.
1. Create/edit `/etc/gitlab/gitlab.rb` and add the following configuration:
```ruby
# Enable service discovery for Prometheus
consul['enable'] = true
consul['monitoring_service_discovery'] = true
# Replace placeholders
# Y.Y.Y.Y consul1.gitlab.example.com Z.Z.Z.Z
# with the addresses of the Consul server nodes
consul['configuration'] = {
retry_join: %w(Y.Y.Y.Y consul1.gitlab.example.com Z.Z.Z.Z),
}
# Set the network addresses that the exporters will listen on
node_exporter['listen_address'] = '0.0.0.0:9100'
pgbouncer_exporter['listen_address'] = '0.0.0.0:9188'
```
1. Run `sudo gitlab-ctl reconfigure` to compile the configuration.
## Administrative console
As part of Omnibus GitLab, a command is provided to automatically connect to the
PgBouncer administrative console. See the
[PgBouncer documentation](https://www.pgbouncer.org/usage.html#admin-console)
for detailed instructions on how to interact with the console.
To start a session run the following and provide the password for the `pgbouncer`
user:
```shell
sudo gitlab-ctl pgb-console
```
To get some basic information about the instance:
```shell
pgbouncer=# show databases; show clients; show servers;
name | host | port | database | force_user | pool_size | reserve_pool | pool_mode | max_connections | current_connections
---------------------+-----------+------+---------------------+------------+-----------+--------------+-----------+-----------------+---------------------
gitlabhq_production | 127.0.0.1 | 5432 | gitlabhq_production | | 100 | 5 | | 0 | 1
pgbouncer | | 6432 | pgbouncer | pgbouncer | 2 | 0 | statement | 0 | 0
(2 rows)
type | user | database | state | addr | port | local_addr | local_port | connect_time | request_time | ptr | link
| remote_pid | tls
------+-----------+---------------------+--------+-----------+-------+------------+------------+---------------------+---------------------+-----------+------
+------------+-----
C | gitlab | gitlabhq_production | active | 127.0.0.1 | 44590 | 127.0.0.1 | 6432 | 2018-04-24 22:13:10 | 2018-04-24 22:17:10 | 0x12444c0 |
| 0 |
C | gitlab | gitlabhq_production | active | 127.0.0.1 | 44592 | 127.0.0.1 | 6432 | 2018-04-24 22:13:10 | 2018-04-24 22:17:10 | 0x12447c0 |
| 0 |
C | gitlab | gitlabhq_production | active | 127.0.0.1 | 44594 | 127.0.0.1 | 6432 | 2018-04-24 22:13:10 | 2018-04-24 22:17:10 | 0x1244940 |
| 0 |
C | gitlab | gitlabhq_production | active | 127.0.0.1 | 44706 | 127.0.0.1 | 6432 | 2018-04-24 22:14:22 | 2018-04-24 22:16:31 | 0x1244ac0 |
| 0 |
C | gitlab | gitlabhq_production | active | 127.0.0.1 | 44708 | 127.0.0.1 | 6432 | 2018-04-24 22:14:22 | 2018-04-24 22:15:15 | 0x1244c40 |
| 0 |
C | gitlab | gitlabhq_production | active | 127.0.0.1 | 44794 | 127.0.0.1 | 6432 | 2018-04-24 22:15:15 | 2018-04-24 22:15:15 | 0x1244dc0 |
| 0 |
C | gitlab | gitlabhq_production | active | 127.0.0.1 | 44798 | 127.0.0.1 | 6432 | 2018-04-24 22:15:15 | 2018-04-24 22:16:31 | 0x1244f40 |
| 0 |
C | pgbouncer | pgbouncer | active | 127.0.0.1 | 44660 | 127.0.0.1 | 6432 | 2018-04-24 22:13:51 | 2018-04-24 22:17:12 | 0x1244640 |
| 0 |
(8 rows)
type | user | database | state | addr | port | local_addr | local_port | connect_time | request_time | ptr | link | rem
ote_pid | tls
------+--------+---------------------+-------+-----------+------+------------+------------+---------------------+---------------------+-----------+------+----
--------+-----
S | gitlab | gitlabhq_production | idle | 127.0.0.1 | 5432 | 127.0.0.1 | 35646 | 2018-04-24 22:15:15 | 2018-04-24 22:17:10 | 0x124dca0 | |
19980 |
(1 row)
```
## Procedure for bypassing PgBouncer
Some database changes have to be done directly, and not through PgBouncer.
Read more about the affected tasks: [database restores](../../raketasks/backup_restore.md#backup-and-restore-for-installations-using-pgbouncer)
and [GitLab upgrades](https://docs.gitlab.com/omnibus/update/README.html#use-postgresql-ha).
1. To find the primary node, run the following on a database node:
```shell
sudo gitlab-ctl repmgr cluster show
```
1. Edit `/etc/gitlab/gitlab.rb` on the application node you're performing the task on, and update
`gitlab_rails['db_host']` and `gitlab_rails['db_port']` with the database
primary's host and port.
1. Run reconfigure:
```shell
sudo gitlab-ctl reconfigure
```
Once you've performed the tasks or procedure, switch back to using PgBouncer:
1. Change back `/etc/gitlab/gitlab.rb` to point to PgBouncer.
1. Run reconfigure:
```shell
sudo gitlab-ctl reconfigure
```
## Troubleshooting
In case you are experiencing any issues connecting through PgBouncer, the first
place to check is always the logs:
```shell
sudo gitlab-ctl tail pgbouncer
```
Additionally, you can check the output from `show databases` in the
[administrative console](#administrative-console). In the output, you would expect
to see values in the `host` field for the `gitlabhq_production` database.
Additionally, `current_connections` should be greater than 1.
### Message: `LOG: invalid CIDR mask in address`
See the suggested fix [in Geo documentation](../geo/replication/troubleshooting.md#message-log--invalid-cidr-mask-in-address).
### Message: `LOG: invalid IP mask "md5": Name or service not known`
See the suggested fix [in Geo documentation](../geo/replication/troubleshooting.md#message-log--invalid-ip-mask-md5-name-or-service-not-known).