GitLab Documentation

Migrating from MySQL to PostgreSQL

Note: This guide assumes you have a working Omnibus GitLab instance with MySQL and want to migrate to bundled PostgreSQL database.

Prerequisites

First, we'll need to enable the bundled PostgreSQL database with up-to-date schema. Next, we'll use pgloader to migrate the data from the old MySQL database to the new PostgreSQL one.

Here's what you'll need to have installed:

Enable bundled PostgreSQL database

  1. Stop GitLab:

    sudo gitlab-ctl stop
    
  2. Edit /etc/gitlab/gitlab.rb to enable bundled PostgreSQL:

    postgresql['enable'] = true
    
  3. Edit /etc/gitlab/gitlab.rb to use the bundled PostgreSQL. Please check all the settings beginning with db_, such as gitlab_rails['db_adapter'] and alike. You could just comment all of them out so that we'll just use the defaults.

  4. Reconfigure GitLab for the changes to take effect:

    sudo gitlab-ctl reconfigure
    
  5. Start Unicorn and PostgreSQL so that we can prepare the schema:

    sudo gitlab-ctl start unicorn
    sudo gitlab-ctl start postgresql
    
  6. Run the following commands to prepare the schema:

    sudo gitlab-rake db:create db:migrate
    
  7. Stop Unicorn to prevent other database access from interfering with the loading of data:

    sudo gitlab-ctl stop unicorn
    

After these steps, you'll have a fresh PostgreSQL database with up-to-date schema.

Migrate data from MySQL to PostgreSQL

Now, you can use pgloader to migrate the data from MySQL to PostgreSQL:

  1. Save the following snippet in a commands.load file, and edit with your database username, password and host:

    LOAD DATABASE
         FROM mysql://username:password@host/gitlabhq_production
         INTO postgresql://gitlab-psql@unix://var/opt/gitlab/postgresql:/gitlabhq_production
    
    WITH include no drop, truncate, disable triggers, create no tables,
         create no indexes, preserve index names, no foreign keys,
         data only
    
    ALTER SCHEMA 'gitlabhq_production' RENAME TO 'public'
    
    ;
    
  2. Start the migration:

    sudo -u gitlab-psql pgloader commands.load
    
  3. Once the migration finishes, you should see a summary table that looks like the following:

                                     table name       read   imported     errors      total time
    -----------------------------------------------  ---------  ---------  ---------  --------------
                                    fetch meta data        119        119          0          0.388s
                                           Truncate        119        119          0          1.134s
    -----------------------------------------------  ---------  ---------  ---------  --------------
                               public.abuse_reports          0          0          0          0.490s
                                 public.appearances          0          0          0          0.488s
                                   public.approvals          0          0          0          0.273s
                        public.application_settings          1          1          0          0.266s
                                   public.approvers          0          0          0          0.339s
                             public.approver_groups          0          0          0          0.357s
                                public.audit_events          1          1          0          0.410s
                                 public.award_emoji          0          0          0          0.441s
                                      public.boards          0          0          0          0.505s
                          public.broadcast_messages          0          0          0          0.498s
                                  public.chat_names          0          0          0          0.576s
                                  public.chat_teams          0          0          0          0.617s
                                   public.ci_builds          0          0          0          0.611s
                          public.ci_group_variables          0          0          0          0.620s
                                public.ci_pipelines          0          0          0          0.599s
                       public.ci_pipeline_schedules          0          0          0          0.622s
              public.ci_pipeline_schedule_variables          0          0          0          0.573s
                       public.ci_pipeline_variables          0          0          0          0.594s
                                  public.ci_runners          0          0          0          0.533s
                          public.ci_runner_projects          0          0          0          0.584s
                        public.ci_sources_pipelines          0          0          0          0.564s
                                   public.ci_stages          0          0          0          0.595s
                                 public.ci_triggers          0          0          0          0.569s
                         public.ci_trigger_requests          0          0          0          0.596s
                                public.ci_variables          0          0          0          0.565s
                      public.container_repositories          0          0          0          0.605s
    public.conversational_development_index_metrics          0          0          0          0.571s
                                 public.deployments          0          0          0          0.607s
                                      public.emails          0          0          0          0.602s
                        public.deploy_keys_projects          0          0          0          0.557s
                                      public.events        160        160          0          0.677s
                                public.environments          0          0          0          0.567s
                                    public.features          0          0          0          0.639s
                        public.events_for_migration        160        160          0          0.582s
                               public.feature_gates          0          0          0          0.579s
                        public.forked_project_links          0          0          0          0.660s
                                   public.geo_nodes          0          0          0          0.686s
                               public.geo_event_log          0          0          0          0.626s
             public.geo_repositories_changed_events          0          0          0          0.677s
                    public.geo_node_namespace_links          0          0          0          0.618s
               public.geo_repository_renamed_events          0          0          0          0.696s
                                    public.gpg_keys          0          0          0          0.704s
               public.geo_repository_deleted_events          0          0          0          0.638s
                             public.historical_data          0          0          0          0.729s
               public.geo_repository_updated_events          0          0          0          0.634s
                              public.index_statuses          0          0          0          0.746s
                              public.gpg_signatures          0          0          0          0.667s
                             public.issue_assignees         80         80          0          0.769s
                                  public.identities          0          0          0          0.655s
                               public.issue_metrics         80         80          0          0.781s
                                      public.issues         80         80          0          0.720s
                                      public.labels          0          0          0          0.795s
                                 public.issue_links          0          0          0          0.707s
                            public.label_priorities          0          0          0          0.793s
                                        public.keys          0          0          0          0.734s
                                 public.lfs_objects          0          0          0          0.812s
                                 public.label_links          0          0          0          0.725s
                                    public.licenses          0          0          0          0.813s
                            public.ldap_group_links          0          0          0          0.751s
                                     public.members         52         52          0          0.830s
                        public.lfs_objects_projects          0          0          0          0.738s
               public.merge_requests_closing_issues          0          0          0          0.825s
                                       public.lists          0          0          0          0.769s
                  public.merge_request_diff_commits          0          0          0          0.840s
                       public.merge_request_metrics          0          0          0          0.837s
                              public.merge_requests          0          0          0          0.753s
                         public.merge_request_diffs          0          0          0          0.771s
                                  public.namespaces         30         30          0          0.874s
                    public.merge_request_diff_files          0          0          0          0.775s
                                       public.notes          0          0          0          0.849s
                                  public.milestones         40         40          0          0.799s
                         public.oauth_access_grants          0          0          0          0.979s
                        public.namespace_statistics          0          0          0          0.797s
                          public.oauth_applications          0          0          0          0.899s
                       public.notification_settings         72         72          0          0.818s
                         public.oauth_access_tokens          0          0          0          0.807s
                               public.pages_domains          0          0          0          0.958s
                       public.oauth_openid_requests          0          0          0          0.832s
                      public.personal_access_tokens          0          0          0          0.965s
                                    public.projects          8          8          0          0.987s
                                  public.path_locks          0          0          0          0.925s
                                       public.plans          0          0          0          0.923s
                            public.project_features          8          8          0          0.985s
                      public.project_authorizations         66         66          0          0.969s
                         public.project_import_data          8          8          0          1.002s
                          public.project_statistics          8          8          0          1.001s
                         public.project_group_links          0          0          0          0.949s
                         public.project_mirror_data          0          0          0          0.972s
        public.protected_branch_merge_access_levels          0          0          0          1.017s
                          public.protected_branches          0          0          0          0.969s
         public.protected_branch_push_access_levels          0          0          0          0.991s
                              public.protected_tags          0          0          0          1.009s
          public.protected_tag_create_access_levels          0          0          0          0.985s
                         public.push_event_payloads          0          0          0          1.041s
                                  public.push_rules          0          0          0          0.999s
                             public.redirect_routes          0          0          0          1.020s
                              public.remote_mirrors          0          0          0          1.034s
                                    public.releases          0          0          0          0.993s
                           public.schema_migrations        896        896          0          1.057s
                                      public.routes         38         38          0          1.021s
                                    public.services          0          0          0          1.055s
                          public.sent_notifications          0          0          0          1.003s
                          public.slack_integrations          0          0          0          1.022s
                                   public.spam_logs          0          0          0          1.024s
                                    public.snippets          0          0          0          1.058s
                               public.subscriptions          0          0          0          1.069s
                                    public.taggings          0          0          0          1.099s
                                    public.timelogs          0          0          0          1.104s
                        public.system_note_metadata          0          0          0          1.038s
                                        public.tags          0          0          0          1.034s
                           public.trending_projects          0          0          0          1.140s
                                     public.uploads          0          0          0          1.129s
                                       public.todos         80         80          0          1.085s
                         public.users_star_projects          0          0          0          1.153s
                           public.u2f_registrations          0          0          0          1.061s
                                   public.web_hooks          0          0          0          1.179s
                                       public.users         26         26          0          1.163s
                          public.user_agent_details          0          0          0          1.068s
                               public.web_hook_logs          0          0          0          1.080s
    -----------------------------------------------  ---------  ---------  ---------  --------------
                            COPY Threads Completion          4          4          0          2.008s
                                    Reset Sequences        113        113          0          0.304s
                                   Install Comments          0          0          0          0.000s
    -----------------------------------------------  ---------  ---------  ---------  --------------
                                  Total import time       1894       1894          0         12.497s
    

    If there is no output for more than 30 minutes, it's possible pgloader encountered an error. See the troubleshooting guide for more details.

  4. Start GitLab:

    sudo gitlab-ctl start
    

Now, you can verify that everything worked by visiting GitLab.

Troubleshooting

Permissions

Note that the PostgreSQL user that you use for the above MUST have superuser privileges. Otherwise, you may see a similar message to the following:

debugger invoked on a CL-POSTGRES-ERROR:INSUFFICIENT-PRIVILEGE in thread
    #<THREAD "lparallel" RUNNING {10078A3513}>:
      Database error 42501: permission denied: "RI_ConstraintTrigger_a_20937" is a system trigger
    QUERY: ALTER TABLE ci_builds DISABLE TRIGGER ALL;
    2017-08-23T00:36:56.782000Z ERROR Database error 42501: permission denied: "RI_ConstraintTrigger_c_20864" is a system trigger
    QUERY: ALTER TABLE approver_groups DISABLE TRIGGER ALL;

Experiencing 500 errors after the migration

If you experience 500 errors after the migration, try to clear the cache:

sudo gitlab-rake cache:clear


Last updated 2017-10-05

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