9.5 KiB
| last_updated |
|---|
| 2018-02-07 |
Migrating from MySQL to PostgreSQL
Note: This guide assumes you have a working GitLab instance with MySQL and want to migrate to bundled PostgreSQL database.
Omnibus installation
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:
- pgloader 3.4.1+
- Omnibus GitLab
- MySQL
Enable bundled PostgreSQL database
-
Stop GitLab:
sudo gitlab-ctl stop -
Edit
/etc/gitlab/gitlab.rbto enable bundled PostgreSQL:postgresql['enable'] = true -
Edit
/etc/gitlab/gitlab.rbto use the bundled PostgreSQL. Please check all the settings beginning withdb_, such asgitlab_rails['db_adapter']and alike. You could just comment all of them out so that we'll just use the defaults. -
Reconfigure GitLab for the changes to take effect:
sudo gitlab-ctl reconfigure -
Start Unicorn and PostgreSQL so that we can prepare the schema:
sudo gitlab-ctl start unicorn sudo gitlab-ctl start postgresql -
Run the following commands to prepare the schema:
sudo gitlab-rake db:create db:migrate -
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:
-
Save the following snippet in a
commands.loadfile, and edit with your databaseusername,passwordandhost: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' ; -
Start the migration:
sudo -u gitlab-psql pgloader commands.load -
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.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 12.497sIf there is no output for more than 30 minutes, it's possible pgloader encountered an error. See the troubleshooting guide for more details.
-
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
Source installation
Prerequisites
Install PostgreSQL and create database
See installation guide.
Install pgloader 3.4.1+
Install directly from your distro:
sudo apt-get install pgloader
If this version is too old, use PostgreSQL's repository:
# add repository
sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
# add key
sudo apt-get install wget ca-certificates
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
# install package
sudo apt-get update
sudo apt-get install pgloader
Enable bundled PostgreSQL database
-
Stop GitLab:
sudo service gitlab stop -
Switch database from MySQL to PostgreSQL
cd /home/git/gitlab sudo -u git mv config/database.yml config/database.yml.bak sudo -u git cp config/database.yml.postgresql config/database.yml sudo -u git -H chmod o-rwx config/database.yml -
Install Gems related to Postgresql
sudo -u git -H rm .bundle/config sudo -u git -H bundle install --deployment --without development test mysql aws kerberos -
Run the following commands to prepare the schema:
sudo -u git -H bundle exec rake db:create db:migrate RAILS_ENV=production
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:
-
Save the following snippet in a
commands.loadfile, and edit with your MySQLusername,passwordandhost:LOAD DATABASE FROM mysql://username:password@host/gitlabhq_production INTO postgresql://postgres@unix://var/run/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' ; -
Start the migration:
sudo -u postgres pgloader commands.load -
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.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 12.497sIf there is no output for more than 30 minutes, it's possible pgloader encountered an error. See the troubleshooting guide for more details.
-
Start GitLab:
sudo service gitlab start
Now, you can verify that everything worked by visiting GitLab.
Troubleshooting
Experiencing 500 errors after the migration
If you experience 500 errors after the migration, try to clear the cache:
sudo -u git -H bundle exec rake cache:clear RAILS_ENV=production