database.md

---
stage: Enablement
group: Distribution
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/#designated-technical-writers
---

# Database settings

GitLab supports only PostgreSQL database management system.

Thus you have two options for database servers to use with Omnibus GitLab:

- Use the packaged PostgreSQL server included with Omnibus GitLab (no
  configuration required, recommended).
- Use an [external PostgreSQL server](#using-a-non-packaged-postgresql-database-management-server).

## Using the PostgreSQL Database Service shipped with Omnibus GitLab

### Configuring SSL

Omnibus automatically enables SSL on the PostgreSQL server, but it will accept
both encrypted and unencrypted connections by default. Enforcing SSL requires
using the `hostssl` configuration in `pg_hba.conf`. For more details, see the
[`pg_hba.conf` documentation](https://www.postgresql.org/docs/11/auth-pg-hba-conf.html).

SSL support depends on the following files:

- The public SSL certificate for the database (`server.crt`).
- The corresponding private key for the SSL certificate (`server.key`).
- A root certificate bundle that validates the server's certificate (`root.crt`).
  By default, Omnibus GitLab uses the embedded certificate bundle in
  `/opt/gitlab/embedded/ssl/certs/cacert.pem`. This isn't required for
  self-signed certificates.

A self-signed certificate and private key will be generated for use. If you'd
prefer to use a CA-signed certificate, use the following steps.

Note that the location of these files can be configurable, but the private key
_must_ be readable by the `gitlab-psql` user. Omnibus manages the permissions of
the files for you, but if the paths are customized, you *must* ensure that the
`gitlab-psql` can access the directory the files are placed in.

For more details, see the [PostgreSQL documentation](https://www.postgresql.org/docs/11/ssl-tcp.html).

Note that `server.crt` and `server.key` may be different from the default SSL
certificates used to access GitLab. For example, suppose the external hostname
of your database is `database.example.com`, and your external GitLab hostname
is `gitlab.example.com`. You will either need a wildcard certificate for
`*.example.com` or two different SSL certificates.

After you have these files, enable SSL:

1. Edit `/etc/gitlab/gitlab.rb`:

   ```ruby
   postgresql['ssl_cert_file'] = '/custom/path/to/server.crt'
   postgresql['ssl_key_file'] = '/custom/path/to/server.key'
   postgresql['ssl_ca_file'] = '/custom/path/to/bundle.pem'
   postgresql['internal_certificate'] = "-----BEGIN CERTIFICATE-----
   ...base64-encoded certificate...
   -----END CERTIFICATE-----
   "
   postgresql['internal_key'] = "-----BEGIN RSA PRIVATE KEY-----
   ...base64-encoded private key...
   -----END RSA PRIVATE KEY-----
   "
   ```

   Relative paths will be rooted from the PostgreSQL data directory
   (`/var/opt/gitlab/postgresql/data` by default).

1. [Reconfigure GitLab](https://docs.gitlab.com/ee/administration/restart_gitlab.html#omnibus-gitlab-reconfigure) to apply the configuration changes.

1. Restart PostgreSQL for the changes to take effect:

   ```shell
   gitlab-ctl restart postgresql
   ```

   If PostgreSQL fails to start, check the logs (for example,
   `/var/log/gitlab/postgresql/current`) for more details.

#### Require SSL

1. Add the following to `/etc/gitlab/gitlab.rb`:

    ```ruby
    postgresql['db_sslmode'] = 'require'
    ```

1. [Reconfigure GitLab](https://docs.gitlab.com/ee/administration/restart_gitlab.html#omnibus-gitlab-reconfigure) to apply the configuration changes.

1. Restart PostgreSQL for the changes to take effect:

   ```shell
   gitlab-ctl restart postgresql
   ```

   If PostgreSQL fails to start, check the logs (for example,
   `/var/log/gitlab/postgresql/current`) for more details.

#### Disabling SSL

1. Add the following to `/etc/gitlab/gitlab.rb`:

   ```ruby
   postgresql['ssl'] = 'off'
   ```

1. [Reconfigure GitLab](https://docs.gitlab.com/ee/administration/restart_gitlab.html#omnibus-gitlab-reconfigure) to apply the configuration changes.

1. Restart PostgreSQL for the changes to take effect:

   ```shell
   gitlab-ctl restart postgresql
   ```

   If PostgreSQL fails to start, check the logs (for example,
   `/var/log/gitlab/postgresql/current`) for more details.

#### Verifying that SSL is being used

To determine whether SSL is being used by clients, you can run:

```shell
gitlab-rails dbconsole
```

At startup, you should see a banner as the following:

```plaintext
psql (9.6.5)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: on)
Type "help" for help.
```

To determine if clients are using SSL, issue this SQL query:

```sql
SELECT * FROM pg_stat_ssl;
```

For example:

```plaintext
gitlabhq_production=> SELECT * FROM pg_stat_ssl;
  pid  | ssl | version |           cipher            | bits | compression | clientdn
-------+-----+---------+-----------------------------+------+-------------+----------
 47506 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
 47509 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
 47510 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
 47527 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
 47528 | f   |         |                             |      |             |
 47537 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
 47560 | f   |         |                             |      |             |
 47561 | f   |         |                             |      |             |
 47563 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
 47564 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
 47565 | f   |         |                             |      |             |
 47569 | f   |         |                             |      |             |
 47570 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
 47573 | f   |         |                             |      |             |
 47585 | f   |         |                             |      |             |
 47586 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
 47618 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
 47628 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
 55812 | t   | TLSv1.2 | ECDHE-RSA-AES256-GCM-SHA384 |  256 | t           |
(19 rows)
```

1. Rows that have `t` listed under the `ssl` column are enabled.
1. Rows that have a value in the `clientdn` are using the `cert` authentication method

#### Configure SSL client authentication

Client SSL certificates can be used to authenticate to the database server. Creating the certificates
is beyond the scope of `omnibus-gitlab`. But users who have an existing SSL certificate management solution
can use this.

##### Configure the database server

1. Create a certificate and key for the server, the common name should equal the DNS name of the server
1. Copy the server certificate, key, and CA file to the PostgreSQL server, and ensure the permissions are correct
   1. The certificate should be owned by the database user (default: `gitlab-psql`)
   1. The key file should be owned by the database user, and its permissions should be `0400`
   1. The CA file should be owned by the database user, and its permissions should be `0400`

   NOTE: **Note:**
   Do not use the filenames `server.crt` or `server.key` for these files. These are reserved for internal use of `omnibus-gitlab`.

1. Ensure the following is set in `gitlab.rb`.

   ```ruby
   postgresql['ssl_cert_file'] = 'PATH_TO_CERTIFICATE'
   postgresql['ssl_key_file'] = 'PATH_TO_KEY_FILE'
   postgresql['ssl_ca_file'] = 'PATH_TO_CA_FILE'
   postgresql['listen_address'] = 'IP_ADDRESS'
   postgresql['cert_auth_addresses'] = {
   'IP_ADDRESS' => {
     'database' => 'gitlabhq_production',
     'user' => 'gitlab'
   }
   ```

   `listen_address` should be set to an IP address of the server that the clients will use to connect to the database.
   `cert_auth_addresses` should contain a list of IP addresses, and the databases and users that are allowed to connect to the database.
1. Run `gitlab-ctl reconfigure` then `gitlab-ctl restart postgresql` in order for the new settings to take effect

#### Configure the Rails client

In order for the rails client to connect to the server, you will need a certficate and key with the `commonName` set to `gitlab`, that is signed by a certificate authority trusted in the CA file specified in `ssl_ca_file` on the database server.

1. Configure `gitlab.rb`

   ```ruby
   gitlab_rails['db_host'] = 'IP_ADDRESS_OR_HOSTNAME_OF_DATABASE_SERVER'
   gitlab_rails['db_sslcert'] = 'PATH_TO_CERTIFICATE_FILE'
   gitlab_rails['db_sslkey'] = 'PATH_TO_KEY_FILE'
   gitlab_rails['db_rootcert'] = 'PATH_TO_CA_FILE'
   ```

1. Run `gitlab-ctl reconfigure` for the rails client to use the new settings
1. Follow the steps in [Verifying that SSL is being used](#verifying-that-ssl-is-being-used) to ensure the authentication is working.

### Configure packaged PostgreSQL server to listen on TCP/IP

The packaged PostgreSQL server can be configured to listen for TCP/IP connections,
with the caveat that some non-critical scripts expect UNIX sockets and may misbehave.

To configure the use of TCP/IP for the database service, make changes to both
the `postgresql` and `gitlab_rails` sections of `gitlab.rb`.

#### Configure PostgreSQL block

The following settings are affected in the `postgresql` block:

- `listen_address`: Controls the address on which PostgreSQL will listen.
- `port`: Controls the port on which PostgreSQL will listen, and _must be set_
  if `listen_address` is.
- `md5_auth_cidr_addresses`: A list of CIDR address blocks which are allowed to
  connect to the server, after authentication with a password.
- `trust_auth_cidr_addresses`: A list of CIDR address blocks which are allowed
  to connect to the server, without authentication of any kind. _Be very careful
  with this setting._ It's suggested that this be limited to the loopback
  address of `127.0.0.1/24` or even `127.0.0.1/32`.
- `sql_user`: Controls the expected username for MD5 authentication. This
  defaults to `gitlab`, and isn't a required setting.
- `sql_user_password`: Sets the password that PostgreSQL will accept for MD5
  authentication. Replace `securesqlpassword` in the following example with an
  acceptable password.

```ruby
postgresql['listen_address'] = '0.0.0.0'
postgresql['port'] = 5432
postgresql['md5_auth_cidr_addresses'] = %w()
postgresql['trust_auth_cidr_addresses'] = %w(127.0.0.1/24)
postgresql['sql_user'] = "gitlab"

##! SQL_USER_PASSWORD_HASH can be generated using the command `gitlab-ctl pg-password-md5 gitlab`,
##! where `gitlab` is the name of the SQL user that connects to GitLab.
postgresql['sql_user_password'] = "SQL_USER_PASSWORD_HASH"

# force ssl on all connections defined in trust_auth_cidr_addresses and md5_auth_cidr_addresses
postgresql['hostssl'] = true
```

Any client or GitLab service which will connect over the network will need to
provide the values of `sql_user` for the username, and password provided to the
configuration when connecting to the PostgreSQL server. They must also be in the
network block provided to `md5_auth_cidr_addresses`

#### Configure GitLab Rails block

To configure the `gitlab-rails` application to connect to the PostgreSQL database
over the network, several settings must be configured:

- `db_host`: Needs to be set to the IP address of the database sever. If this is
  on the same instance as the PostgreSQL service, this can be `127.0.0.1` and _will
  not require_ password authentication.
- `db_port`: Sets the port on the PostgreSQL server to connect to, and _must be set_
  if `db_host` is set.
- `db_username`: Configures the username with which to connect to PostgreSQL. This
  defaults to `gitlab`.
- `db_password`: Must be provided if connecting to PostgreSQL over TCP/IP, and from
  an instance in the `postgresql['md5_auth_cidr_addresses']` block from settings
  above. This is not required if you are connecting to `127.0.0.1` and have configured
  `postgresql['trust_auth_cidr_addresses']` to include it.

```ruby
gitlab_rails['db_host'] = '127.0.0.1'
gitlab_rails['db_port'] = 5432
gitlab_rails['db_username'] = "gitlab"
gitlab_rails['db_password'] = "securesqlpassword"
```

#### Apply and restart services

After making the previous changes, an administrator should run `gitlab-ctl reconfigure`.
If you experience any issues in regards to the service not listening on TCP, try
directly restarting the service with `gitlab-ctl restart postgresql`.

Some included scripts of the Omnibus package (such as `gitlab-psql`) expect the
connections to PostgreSQL to be handled over the UNIX socket, and may not function
properly. You can enable TCP/IP without disabling UNIX sockets.

### Enabling PostgreSQL WAL (Write Ahead Log) Archiving

By default, WAL archiving of the packaged PostgreSQL isn't enabled. Consider the
following when seeking to enable WAL archiving:

- The WAL level needs to be 'replica' or higher (9.6+ options are `minimal`,
  `replica`, or `logical`)
- Increasing the WAL level will increase the amount of storage consumed in
  regular operations

To enable WAL Archiving:

1. Edit `/etc/gitlab/gitlab.rb`:

   ```ruby
   # Replication settings
   postgresql['sql_replication_user'] = "gitlab_replicator"
   postgresql['wal_level'] = "replica"
       ...
       ...
   # Backup/Archive settings
   postgresql['archive_mode'] = "on"
   postgresql['archive_command'] = "/your/wal/archiver/here"
   postgresql['archive_timeout'] = "60"
   ```

1. [Reconfigure GitLab](https://docs.gitlab.com/ee/administration/restart_gitlab.html#omnibus-gitlab-reconfigure) for the changes to take effect. This will result in a database restart.

### Store PostgreSQL data in a different directory

By default, everything is stored under `/var/opt/gitlab/postgresql`, controlled
by the `postgresql['dir']` attribute.

This consists of:

- The database socket will be `/var/opt/gitlab/postgresql/.s.PGSQL.5432`. This
  is controlled by `postgresql['unix_socket_directory']`.
- The `gitlab-psql` system user will have its `HOME` directory set to this. This
  is controlled by `postgresql['home']`.
- The actual data will be stored in `/var/opt/gitlab/postgresql/data`.

To change the location of the PostgreSQL data

CAUTION: **Caution:**
If you have an existing database, you need to move the data to the new location
first.

CAUTION: **Caution:**
This is an intrusive operation. It cannot be done without downtime on an
existing installation

1. If this is an existing installation, stop GitLab: `gitlab-ctl stop`.
1. Update `postgresql['dir']` to the desired location.
1. Run `gitlab-ctl reconfigure`.
1. Start GitLab `gitlab-ctl start`.

### Upgrade packaged PostgreSQL server

Omnibus GitLab provides the `gitlab-ctl pg-upgrade` command to update the
packaged PostgreSQL server to a later version (if one is included in the
package). This updates PostgreSQL to the [default shipped version](../package-information/postgresql_versions.md)
during package upgrades, unless specifically [opted out](#opt-out-of-automatic-postgresql-upgrades).

CAUTION: **Before upgrading:**
It's important that you fully read this section before running any commands. For
single node installations, this upgrade needs downtime, as the database must be
down while the upgrade is being performed. The length of time depends on the
size of your database. To avoid downtime, it's possible to upgrade to a new
database [using Slony](https://docs.gitlab.com/ee/update/upgrading_postgresql_using_slony.html).

TIP: **Tip:**
If you encounter any problems during upgrade, raise an issue with a full
description at the [Omnibus GitLab issue tracker](https://gitlab.com/gitlab-org/omnibus-gitlab).

To upgrade the PostgreSQL version, be sure that:

- You're running the latest version of GitLab, and it's working.
- If you recently upgraded, you ran `sudo gitlab-ctl reconfigure` successfully
  before you proceed.
- You have sufficient disk space for two copies of your database. _Do not attempt
  to upgrade unless you have enough free space available._

  - Check your database size using `sudo du -sh /var/opt/gitlab/postgresql/data`
    (or update to your database path).
  - Check the space available using `sudo df -h`. If the partition where the
    database resides doesn't have enough space, pass the argument `--tmp-dir $DIR`
    to the command. GitLab 13.3 includes an available disk space check and aborts
    the upgrade if the requirements aren't met.

After you confirm that the above checklist is satisfied, you can proceed with
the upgrade:

```shell
sudo gitlab-ctl pg-upgrade
```

TIP: **Tip:**
`pg-upgrade` can take arguments; for example, you can set the timeout for the
execution of the underlying commands (`--timeout=1d2h3m4s5ms`). Run `gitlab-ctl pg-upgrade -h`
to see the full list.

`gitlab-ctl pg-upgrade` performs the following steps:

1. Checks to ensure the database is in a known good state.
1. Checks if there's enough free disk space and aborts otherwise. You can skip this by appending the `--skip-disk-check` flag.
1. Shuts down the existing database, any unnecessary services, and enables the GitLab deploy page.
1. Changes the symlinks in `/opt/gitlab/embedded/bin/` for PostgreSQL to point to the newer version of the database.
1. Creates a new directory containing a new, empty database with a locale matching the existing database.
1. Uses the `pg_upgrade` tool to copy the data from the old database to the new database.
1. Moves the old database out of the way.
1. Moves the new database to the expected location.
1. Calls `sudo gitlab-ctl reconfigure` to do the required configuration changes and starts the new database server.
1. Starts the remaining services and removes the deploy page.
1. If any errors are detected during this process, it reverts to the old version of the database.

After the upgrade is complete, verify that everything is working as expected.

_After you have verified that your GitLab instance is running correctly_, you
can clean up the old database files:

```shell
sudo rm -rf /var/opt/gitlab/postgresql/data.<old_version>
sudo rm -f /var/opt/gitlab/postgresql-version.old
```

You can find details of PostgreSQL versions shipped with various GitLab versions
in [PostgreSQL versions shipped with Omnibus GitLab](../package-information/postgresql_versions.md).

#### Opt out of automatic PostgreSQL upgrades

To opt out of automatic PostgreSQL upgrade during GitLab package upgrades, run:

```shell
sudo touch /etc/gitlab/disable-postgresql-upgrade
```

#### GitLab 13.3 and later

As of GitLab 13.3, PostgreSQL 11.7 and 12.3 are both shipped with Omnibus.
During a package upgrade, the database isn't upgraded to PostgreSQL 12. If you
want to upgrade to PostgreSQL 12, you must do it manually:

```shell
sudo gitlab-ctl pg-upgrade -V 12
```

PostgreSQL 12 isn't supported on Geo deployments and is [planned](https://gitlab.com/groups/gitlab-org/-/epics/2374)
for the future releases. The [fault-tolerant PostgreSQL 12 deployment](https://docs.gitlab.com/ee/administration/postgresql/replication_and_failover.html)
is possible only by using Patroni. Repmgr is no longer supported for
PostgreSQL 12.

#### GitLab 12.10 and later

The default PostgreSQL version is set to 11.x, and an upgrade of the database is
done on package upgrades for installs that are not using repmgr or Geo.

The upgrade is skipped in any of the following cases:

- You're running the database in high availability using repmgr.
- Your database nodes are part of GitLab Geo configuration.
- You have specifically [opted out](#opt-out-of-automatic-postgresql-upgrades).

To upgrade PostgreSQL on installs with HA or Geo, see [Packaged PostgreSQL deployed in an HA/Geo Cluster](#packaged-postgresql-deployed-in-an-hageo-cluster).

#### GitLab 12.8 and later

**As of GitLab 12.8, PostgreSQL 9.6.17, 10.12, and 11.7 are shipped with
Omnibus GitLab.**

During package upgrades (unless opted out) and when user manually runs
`gitlab-ctl pg-upgrade`, `omnibus-gitlab` will still be attempting to upgrade
the database only to 10.x, while 11.x will be available for users to manually
upgrade to. To manually update PostgreSQL to version 11.x , the `pg-upgrade`
command has to be passed with a version argument (`-V` or `--target-version`):

```shell
sudo gitlab-ctl pg-upgrade -V 11
```

#### GitLab 12.0 and later

**As of GitLab 12.0, PostgreSQL 9.6.11 and 10.7 are shipped with Omnibus
GitLab.**

On upgrades, we will be upgrading the database to 10.7 unless specifically opted
out, as previously described.

#### GitLab 11.11 and later

**As of GitLab 11.11, PostgreSQL 9.6.X and 10.7 are shipped with Omnibus
GitLab.**

Fresh installs will be getting PostgreSQL 10.7 while GitLab package upgrades
will retain the existing version of PostgreSQL. Users can manually upgrade to
the 10.7 using the `pg-upgrade` command as previously mentioned.

### Revert packaged PostgreSQL server to previous version

DANGER: **Danger:**
This operation will revert your current database, _including its data_, to its state
before your last upgrade. Be sure to create a backup before attempting to downgrade
your packaged PostgreSQL database.

On GitLab versions which ship multiple PostgreSQL versions, users can downgrade
an already upgraded PostgreSQL version to the earlier version using the `gitlab-ctl
revert-pg-upgrade` command. This command also supports the `-V` flag to specify
a target version for scenarios where more than two PostgreSQL versions are shipped in
the package (for example: GitLab 12.8 where PostgreSQL 9.6.x, 10.x, and 11.x are
shipped).

If the target version is not specified, it will use the version in `/var/opt/gitlab/postgresql-version.old`
if available. Otherwise, it falls back to the default version shipped with GitLab.

On other GitLab versions which ship only one PostgreSQL version, you can't
downgrade your PostgreSQL version. You must downgrade GitLab to an older version for
this.

### Connecting to the bundled PostgreSQL database

If you need to connect to the bundled PostgreSQL database and are using the
default Omnibus GitLab database configuration, you can connect as the
application user:

```shell
sudo gitlab-rails dbconsole
```

or as a PostgreSQL superuser:

```shell
sudo gitlab-psql -d gitlabhq_production
```

## Using a non-packaged PostgreSQL database management server

By default, GitLab is configured to use the PostgreSQL server that's included
in Omnibus GitLab. You can also reconfigure it to use an external instance of
PostgreSQL.

CAUTION: **Caution:**
If you are using non-packaged PostgreSQL server, you need to make
sure that PostgreSQL is set up according to the [database requirements document](https://docs.gitlab.com/ee/install/requirements.html#database).

1. Edit `/etc/gitlab/gitlab.rb`:

   ```ruby
   # Disable the built-in Postgres
   postgresql['enable'] = false

   # Fill in the connection details for database.yml
   gitlab_rails['db_adapter'] = 'postgresql'
   gitlab_rails['db_encoding'] = 'utf8'
   gitlab_rails['db_host'] = '127.0.0.1'
   gitlab_rails['db_port'] = 5432
   gitlab_rails['db_username'] = 'USERNAME'
   gitlab_rails['db_password'] = 'PASSWORD'
   ```

   Don't forget to remove the `#` comment characters at the beginning of these
   lines.

   Note that:

   - `/etc/gitlab/gitlab.rb` should have file permissions `0600` because it contains
     plain-text passwords.
   - PostgreSQL allows to listen on [multiple addresses](https://www.postgresql.org/docs/11/runtime-config-connection.html)

     If you use multiple addresses in `gitlab_rails['db_host']`, comma-separated, the first address in the list will be used for connection.

1. [Reconfigure GitLab](https://docs.gitlab.com/ee/administration/restart_gitlab.html#omnibus-gitlab-reconfigure) for the changes to take effect.

1. [Seed the database](#seed-the-database-fresh-installs-only).

### UNIX socket configuration for non-packaged PostgreSQL

If you want to use your system's PostgreSQL server (installed on the same system
as GitLab) instead of the one bundled with GitLab, you can do so by using a UNIX
socket:

1. Edit `/etc/gitlab/gitlab.rb`:

   ```ruby
   # Disable the built-in Postgres
   postgresql['enable'] = false

   # Fill in the connection details for database.yml
   gitlab_rails['db_adapter'] = 'postgresql'
   gitlab_rails['db_encoding'] = 'utf8'
   # The path where the socket lives
   gitlab_rails['db_host'] = '/var/run/postgresql/'
   ```

1. Reconfigure GitLab for the changes to take effect:

   ```ruby
   sudo gitlab-ctl-reconfigure
   ```

### Configuring SSL

#### Require SSL

1. Add the following to `/etc/gitlab/gitlab.rb`:

   ```ruby
   postgresql['db_sslmode'] = 'require'
   ```

1. [Reconfigure GitLab](https://docs.gitlab.com/ee/administration/restart_gitlab.html#omnibus-gitlab-reconfigure) to apply the configuration changes.

1. Restart PostgreSQL for the changes to take effect:

   ```shell
   gitlab-ctl restart postgresql
   ```

   If PostgreSQL fails to start, check the logs (for example,
   `/var/log/gitlab/postgresql/current`) for more details.

#### Require SSL and verify server certificate against CA bundle

PostgreSQL can be configured to require SSL and verify the server certificate
against a CA bundle to prevent spoofing.
The CA bundle that's specified in `gitlab_rails['db_sslrootcert']` must contain
both the root and intermediate certificates.

1. Add the following to `/etc/gitlab/gitlab.rb`:

   ```ruby
   gitlab_rails['db_sslmode'] = "verify-full"
   gitlab_rails['db_sslrootcert'] = "your-full-ca-bundle.pem"
   ```

   If you are using Amazon RDS for your PostgreSQL server, ensure you
   download and use the [combined CA bundle](https://s3.amazonaws.com/rds-downloads/rds-combined-ca-bundle.pem)
   for `gitlab_rails['db_sslrootcert']`. More information on this can be found
   in the [using SSL/TLS to Encrypt a Connection to a DB Instance](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/UsingWithRDS.SSL.html)
   article on AWS.

1. [Reconfigure GitLab](https://docs.gitlab.com/ee/administration/restart_gitlab.html#omnibus-gitlab-reconfigure) to apply the configuration changes.

1. Restart PostgreSQL for the changes to take effect:

   ```shell
   gitlab-ctl restart postgresql
   ```

   If PostgreSQL fails to start, check the logs (for example,
   `/var/log/gitlab/postgresql/current`) for more details.

### Backup and restore a non-packaged PostgreSQL database

When using the [Rake backup create and restore task](https://docs.gitlab.com/ee/raketasks/backup_restore.html#create-a-backup-of-the-gitlab-system), GitLab will
attempt to use the packaged `pg_dump` command to create a database backup file
and the packaged `psql` command to restore a backup. This will only work if
they are the correct versions. Check the versions of the packaged `pg_dump` and
`psql`:

```shell
/opt/gitlab/embedded/bin/pg_dump --version
/opt/gitlab/embedded/bin/psql --version
```

If these versions are different from your non-packaged external PostgreSQL, you
will need to install tools that match your database version and then follow the
steps below. There are multiple ways to install PostgreSQL client tools. See
<https://www.postgresql.org/download/> for options.

Once the correct `psql` and `pg_dump` tools are available on your system, follow
these steps, using the correct path to the location you installed the new tools:

1. Add symbolic links to the non-packaged versions:

   ```shell
   ln -s /path/to/new/pg_dump /path/to/new/psql /opt/gitlab/bin/
   ```

1. Check the versions:

   ```shell
   /opt/gitlab/bin/pg_dump --version
   /opt/gitlab/bin/psql --version
   ```

   They should now be the same as your non-packaged external PostgreSQL.

After this is done, ensure that the backup and restore tasks are using the
correct executables by running both the [backup](https://docs.gitlab.com/ee/raketasks/backup_restore.html#create-a-backup-of-the-gitlab-system) and
[restore](https://docs.gitlab.com/ee/raketasks/backup_restore.html#restore-a-previously-created-backup) tasks.

### Upgrade a non-packaged PostgreSQL database

Before proceeding with the upgrade, note the following:

- Before upgrading, review the [GitLab and PostgreSQL version compatibility table](../package-information/postgresql_versions.md)
  to determine your upgrade path. When using GitLab backup or restore, you
  _must_ keep the same version of GitLab; first upgrade PostgreSQL, and then GitLab.
- The [backup and restore Rake task](https://docs.gitlab.com/ee/raketasks/backup_restore.html#create-a-backup-of-the-gitlab-system)
  can be used to back up and restore the database to a later version of PostgreSQL.
- If configuring a version number whose binaries are unavailable on the file
  system, GitLab/Rails uses the default database's version binaries (default as
  per [GitLab and PostgreSQL version compatibility table](../package-information/postgresql_versions.md)).
- If you're using Amazon RDS and are seeing extremely high (near 100%) CPU
  utilization following a major version upgrade (for example, from `10.x` to
  `11.x`), running an `ANALYZE VERBOSE;` query may be necessary to recreate query
  plans and reduce CPU utilization on the database server(s).
  [Amazon recommends this](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_UpgradeDBInstance.PostgreSQL.html)
  as part of a major version upgrade.

The following example demonstrates upgrading from a database host running PostgreSQL 10 to another database host running PostgreSQL 11 and incurs downtime:

1. Spin up a new PostgreSQL 11 database server that's set up according to the [database requirements](https://docs.gitlab.com/ee/install/requirements.html#database).

1. Ensure that the compatible versions of `pg_dump` and `pg_restore` are being
   used on the GitLab Rails instance. To amend GitLab configuration, edit
   `/etc/gitlab/gitlab.rb` and specify the value of `postgresql['version']`:

    ```ruby
    postgresql['version'] = 11
    ```

  NOTE: **Note:**
  Connecting to PostgreSQL 12 (alongside with amending `postgresql['version'] = 12`)
  breaks the [GitLab Backup/Restore](https://docs.gitlab.com/ee/raketasks/backup_restore.html) functionality unless the v12 client binaries are available on the file system. More on this topic can be found under [backup and restore a non-packaged database](#backup-and-restore-a-non-packaged-postgresql-database).
  This problem with missing 12 client binaries is partially resolved in GitLab 13.3,
  where PostgreSQL 12 is shipped with Omnibus GitLab, and it's being tackled in
  the [support for PostgreSQL 12](https://gitlab.com/groups/gitlab-org/-/epics/2374) epic.

1. Reconfigure GitLab:

   ```shell
   sudo gitlab-ctl reconfigure
   ```

1. Stop GitLab (note that this step will cause downtime):

   ```shell
   sudo gitlab-ctl stop
   ```

1. Run the backup Rake task using the SKIP options to back up only the database.
   Make a note of the backup file name; you'll use it later to restore.

   ```shell
   sudo gitlab-backup create SKIP=repositories,uploads,builds,artifacts,lfs,pages,registry
   ```

1. Shutdown the PostgreSQL 10 database host.

1. Edit `/etc/gitlab/gitlab.rb` and update the `gitlab_rails['db_host']` setting
   to point to the PostgreSQL database 11 host.

1. Reconfigure GitLab:

   ```shell
   sudo gitlab-ctl reconfigure
   ```

1. Restore the database using the database backup file created earlier, and be
   sure to answer **no** when asked "This task will now rebuild the authorized_keys file":

   ```shell
   sudo gitlab-backup restore BACKUP=<database-backup-filename>
   ```

1. Start GitLab:

   ```shell
   sudo gitlab-ctl start
   ```

### Seed the database (fresh installs only)

CAUTION: **Caution:**
This is a destructive command; do not run it on an existing database.

Omnibus GitLab will not seed your external database. Run the following command
to import the schema and create the first administration user:

```shell
# Remove 'sudo' if you are the 'git' user
sudo gitlab-rake gitlab:setup
```

If you want to specify a password for the default `root` user, specify the
`initial_root_password` setting in `/etc/gitlab/gitlab.rb` before running the
`gitlab:setup` command above:

```ruby
gitlab_rails['initial_root_password'] = 'nonstandardpassword'
```

If you want to specify the initial registration token for shared GitLab Runners,
specify the `initial_shared_runners_registration_token` setting in `/etc/gitlab/gitlab.rb`
before running the `gitlab:setup` command:

```ruby
gitlab_rails['initial_shared_runners_registration_token'] = 'token'
```

### Pin the packaged PostgreSQL version (fresh installs only)

NOTE: **Note:**
GitLab 13.0 only ships with PostgreSQL 11. PostgreSQL 12 is only available from GitLab 13.3 onward.
PostgreSQL 12 is not supported on Geo deployments and is [planned](https://gitlab.com/groups/gitlab-org/-/epics/2374)
for the future releases. The [fault-tolerant PostgreSQL 12 deployment](https://docs.gitlab.com/ee/administration/postgresql/replication_and_failover.html)
is only possible using Patroni. Repmgr is no longer supported for PostgreSQL 12.

Omnibus GitLab will initialize PostgreSQL with the [default version](../package-information/postgresql_versions.md).

To initialize PostgreSQL with a non-default version, you can set `postgresql['version']` to the major version one of
the [packaged PostgreSQL versions](../package-information/postgresql_versions.md) prior to the initial reconfigure.
For example, starting GitLab 13.3 you can use `postgresql['version'] = 12` to opt in to use PostgreSQL 12.

CAUTION: **Caution:**
Setting `postgresql['version']` while using the Omnibus packaged PostgreSQL after the initial reconfigure will
throw errors about the data directory being initialized on a different version of PostgreSQL. If this is encountered,
see [Revert packaged PostgreSQL server to previous version](#revert-packaged-postgresql-server-to-previous-version).

### Troubleshooting

#### Set `default_transaction_isolation` into `read committed`

If you see errors similar to the following in your `production/sidekiq` log:

```plaintext
ActiveRecord::StatementInvalid PG::TRSerializationFailure: ERROR:  could not serialize access due to concurrent update
```

Chances are your database's `default_transaction_isolation` configuration is not
in line with GitLab application requirement. You can check this configuration by
connecting to your PostgreSQL database and run `SHOW default_transaction_isolation;`.
GitLab application expects `read committed` to be configured.

This `default_transaction_isolation` configuration is set in your
`postgresql.conf` file. You will need to restart/reload the database once you
changed the configuration. This configuration comes by default in the packaged
PostgreSQL server included with Omnibus GitLab.

## Application Settings for the Database

### Disabling automatic database migration

If you have multiple GitLab servers sharing a database, you will want to limit the
number of nodes that are performing the migration steps during reconfiguration.

Edit `/etc/gitlab/gitlab.rb`:

```ruby
# Enable or disable automatic database migrations
gitlab_rails['auto_migrate'] = false
```

Don't forget to remove the `#` comment characters at the beginning of this
line.

`/etc/gitlab/gitlab.rb` should have file permissions `0600` because it contains
plain-text passwords.

The next time a reconfigure is triggered, the migration steps will not be performed.

### Setting client statement_timeout

The amount of time that Rails will wait for a database transaction to complete
before timing out can now be adjusted with the `gitlab_rails['db_statement_timeout']`
setting. By default, this setting is not used.

Edit `/etc/gitlab/gitlab.rb`:

```ruby
gitlab_rails['db_statement_timeout'] = 45000
```

In this case the client `statement_timeout` is set to 45 seconds. The value
is specified in milliseconds.

### Setting connection timeout

The amount of time that Rails will wait for a PostgreSQL connection attempt to succeed
before timing out can be adjusted with the `gitlab_rails['db_connect_timeout']`
setting. By default, this setting is not used:

1. Edit `/etc/gitlab/gitlab.rb`:

   ```ruby
   gitlab_rails['db_connect_timeout'] = 5
   ```

1. Reconfigure GitLab:

   ```shell
   sudo gitlab-ctl reconfigure
   ```

In this case the client `connect_timeout` is set to 5 seconds. The value
is specified in seconds. A minimum value of 2 seconds applies. Setting this to `<= 0`
or not specifying the setting at all disables the timeout.

## Automatic database reindexing

> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/249662) in GitLab 13.5.

CAUTION: **Warning:**
This is an experimental feature that isn't enabled by default.

Recreates database indexes in the background (called "reindexing"). This can
be used to remove bloated space that has accumulated in indexes and helps to maintain healthy and
efficient indexes.

The reindexing task can be started regularly through a cronjob. To configure the cronjob,
`gitlab_rails['database_reindexing']['enable']` should be set to `true`.

In a multi-node environment, this feature should only be enabled on an application host.
The reindexing process cannot go through PgBouncer, it has to have a direct database connection.

By default, this starts the cronjob every hour during weekends (likely a low-traffic time) only.

You can change the schedule by refining the following settings:

1. Edit `/etc/gitlab/gitlab.rb`:

   ```shell
   gitlab_rails['database_reindexing']['hour'] = '*'
   gitlab_rails['database_reindexing']['minute'] = 0
   gitlab_rails['database_reindexing']['month'] = '*'
   gitlab_rails['database_reindexing']['day_of_month'] = '*'
   gitlab_rails['database_reindexing']['day_of_week'] = '0,6'
   ```

1. Reconfigure GitLab:

   ```shell
   sudo gitlab-ctl reconfigure
   ```

## Packaged PostgreSQL deployed in an HA/Geo Cluster

### Upgrading a GitLab HA cluster

NOTE: **Note:**
As of GitLab 13.3, PostgreSQL 12 is shipped with Omnibus GitLab. However, the current support for is limited to
single database node installation. [Fault-tolerant PostgreSQL deployments](https://docs.gitlab.com/ee/administration/postgresql/replication_and_failover.html),
and Geo installations are not supported, but [planned](https://gitlab.com/groups/gitlab-org/-/epics/2374) for the future releases.

The following instructions are valid for a fault tolerant setup with repmgr. To upgrade PostgreSQL version in a
Patroni cluster see [Upgrading PostgreSQL major version in a Patroni cluster](https://docs.gitlab.com/ee/administration/postgresql/replication_and_failover.html#upgrading-postgresql-major-version-in-a-patroni-cluster).

If [PostgreSQL is configured for high availability](https://docs.gitlab.com/ee/administration/postgresql/index.html),
`pg-upgrade` should be run on all the nodes running PostgreSQL. Other nodes can be
skipped, but must be running the same GitLab version as the database nodes.

Follow the steps below to upgrade the database nodes:

1. Secondary nodes must be upgraded before the primary node.
   1. On the secondary nodes, edit `/etc/gitlab/gitlab.rb` to include the following:

   ```shell
   # Replace X with value of number of db nodes + 1
   postgresql['max_replication_slots'] = X
    ```

   1. Run `gitlab-ctl reconfigure` to update the configuration.
   1. Run `sudo gitlab-ctl restart postgresql` to get PostgreSQL restarted with the new configuration.
   1. On running `pg-upgrade` on a PostgreSQL secondary node, the node will be removed
      from the cluster.
   1. Once all the secondary nodes are upgraded using `pg-upgrade`, the user
      will be left with a single-node cluster that has only the primary node.
   1. `pg-upgrade`, on secondary nodes will not update the existing data to
      match the new version, as that data will be replaced by the data from
      primary node. It will, however move the existing data to a backup
      location.
1. Once all secondary nodes are upgraded, run `pg-upgrade` on primary node.
   1. On the primary node, edit `/etc/gitlab/gitlab.rb` to include the following:

   ```shell
   # Replace X with value of number of db nodes + 1
   postgresql['max_replication_slots'] = X
    ```

   1. Run `gitlab-ctl reconfigure` to update the configuration.
   1. Run `sudo gitlab-ctl restart postgresql` to get PostgreSQL restarted with the new configuration.
   1. On a primary node, `pg-upgrade` will update the existing data to match
      the new PostgreSQL version.
1. Recreate the secondary nodes by running the following command on each of them

   ```shell
   gitlab-ctl repmgr standby setup MASTER_NODE_NAME
   ```

1. Check if the repmgr cluster is back to the original state

   ```shell
   gitlab-ctl repmgr cluster show
   ```