105 lines
2.7 KiB
Markdown
105 lines
2.7 KiB
Markdown
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---
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stage: Enablement
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group: Sharding
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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
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---
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# Multiple Databases
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In order to scale GitLab, the GitLab application database
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will be [decomposed into multiple
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databases](https://gitlab.com/groups/gitlab-org/-/epics/6168).
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## CI Database
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Support for configuring the GitLab Rails application to use a distinct
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database for CI tables was added in [GitLab
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14.1](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/64289). This
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feature is still under development, and is not ready for production use.
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By default, GitLab is configured to use only one main database. To
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opt-in to use a main database, and CI database, modify the
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`config/database.yml` file to have a `primary` and a `ci` database
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configurations. For example, given a `config/database.yml` like below:
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```yaml
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development:
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adapter: postgresql
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encoding: unicode
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database: gitlabhq_development
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host: /path/to/gdk/postgresql
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pool: 10
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prepared_statements: false
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variables:
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statement_timeout: 120s
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test: &test
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adapter: postgresql
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encoding: unicode
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database: gitlabhq_test
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host: /path/to/gdk/postgresql
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pool: 10
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prepared_statements: false
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variables:
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statement_timeout: 120s
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```
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Edit the `config/database.yml` to look like this:
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```yaml
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development:
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primary:
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adapter: postgresql
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encoding: unicode
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database: gitlabhq_development
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host: /path/to/gdk/postgresql
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pool: 10
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prepared_statements: false
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variables:
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statement_timeout: 120s
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ci:
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adapter: postgresql
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encoding: unicode
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database: gitlabhq_development_ci
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migrations_paths: db/ci_migrate
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host: /path/to/gdk/postgresql
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pool: 10
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prepared_statements: false
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variables:
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statement_timeout: 120s
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test: &test
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primary:
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adapter: postgresql
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encoding: unicode
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database: gitlabhq_test
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host: /path/to/gdk/postgresql
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pool: 10
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prepared_statements: false
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variables:
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statement_timeout: 120s
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ci:
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adapter: postgresql
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encoding: unicode
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database: gitlabhq_test_ci
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migrations_paths: db/ci_migrate
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host: /path/to/gdk/postgresql
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pool: 10
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prepared_statements: false
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variables:
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statement_timeout: 120s
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```
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Note that we use `primary` in the `config/database.yml` to refer to the main
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database. This is to match the default name Rails has.
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### Migrations
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Any migrations that affect `Ci::ApplicationRecord` models
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and their tables must be placed in two directories for now:
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- `db/migrate`
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- `db/ci_migrate`
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We aim to keep the schema for both tables the same across both databases.
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