--- 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).