Please proceed to the rest of the installation **before** running through the steps below.
### `log_bin_trust_function_creators`
If you use MySQL with replication, or just have MySQL configured with binary logging, all of your MySQL servers will need to have `log_bin_trust_function_creators` enabled to allow the use of `TRIGGER` in migrations. You have already set this global variable in the steps above, but to make it persistent, add the following to your `my.cnf` file:
GitLab 8.14 has introduced [a feature](https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7420) requiring `utf8mb4` encoding to be supported in your GitLab MySQL Database, which is not the case if you have setup your database before GitLab 8.16.
Follow the below instructions to ensure you use the most up to date requirements for your GitLab MySQL Database.
**We are about to do the following:**
- Ensure you can enable `utf8mb4` encoding and `utf8mb4_general_ci` collation for your GitLab DB, tables and data.
- Convert your GitLab tables and data from `utf8`/`utf8_general_ci` to `utf8mb4`/`utf8mb4_general_ci`
We need to check, enable and maybe convert your existing GitLab DB tables to the [InnoDB File-Per-Table Tablespaces](http://dev.mysql.com/doc/refman/5.7/en/innodb-multiple-tablespaces.html) as a prerequisite for supporting **utfb8mb4 with long indexes** required by recent GitLab databases.
# Check your MySQL version is >= 5.5.3 (GitLab requires 5.5.14+)
mysql > SHOW VARIABLES LIKE 'version';
+---------------+-----------------+
| Variable_name | Value |
+---------------+-----------------+
| version | 5.5.53-0+deb8u1 |
+---------------+-----------------+
# Note where is your MySQL data dir for later:
mysql > select @@datadir;
+----------------+
| @@datadir |
+----------------+
| /var/lib/mysql |
+----------------+
# Note whether your MySQL server runs with innodb_file_per_table ON or OFF:
mysql> SELECT @@innodb_file_per_table;
+-------------------------+
| @@innodb_file_per_table |
+-------------------------+
| 1 |
+-------------------------+
# You can now quit the database session
mysql> \q
> You need **MySQL 5.5.3 or later** to perform this update.
Whatever the results of your checks above, we now need to check if your GitLab database has been created using [InnoDB File-Per-Table Tablespaces](http://dev.mysql.com/doc/refman/5.7/en/innodb-multiple-tablespaces.html) (i.e. `innodb_file_per_table` was set to **1** at initial setup time).
> Note: This setting is [enabled by default](http://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_file_per_table) since MySQL 5.6.6.
# Run this command with root privileges, replace the data dir if different:
sudo ls -lh /var/lib/mysql/gitlabhq_production/*.ibd | wc -l
# Run this command with root privileges, replace the data dir if different:
sudo ls -lh /var/lib/mysql/gitlabhq_production/*.frm | wc -l
- If `SELECT @@innodb_file_per_table` returned **1** previously, your server is running correctly.
> It's however a requirement to check *now* that this setting is indeed persisted in your [my.cnf](https://dev.mysql.com/doc/refman/5.7/en/tablespace-enabling.html) file!
- If `SELECT @@innodb_file_per_table` returned **0** previously, your server is not running correctly.
> [Enable innodb_file_per_table](https://dev.mysql.com/doc/refman/5.7/en/tablespace-enabling.html) by running in a MySQL session as root the command `SET GLOBAL innodb_file_per_table=1, innodb_file_format=Barracuda;` and persist the two settings in your [my.cnf](https://dev.mysql.com/doc/refman/5.7/en/tablespace-enabling.html) file
Now, if you have a **different result** returned by the 2 commands above, it means you have a **mix of tables format** uses in your GitLab database. This can happen if your MySQL server had different values for `innodb_file_per_table` in its life and you updated GitLab at different moments with those inconsistent values. So keep reading.
- **Case 2: a result equals to "0" OR not the same result for both commands**
Unfortunately, none or only some of your GitLab database tables use the GitLab requirement of [InnoDB File-Per-Table Tablespaces](http://dev.mysql.com/doc/refman/5.7/en/innodb-multiple-tablespaces.html).
# Enable innodb_file_per_table and set innodb_file_format on the running server:
mysql > SET GLOBAL innodb_file_per_table=1, innodb_file_format=Barracuda;
# You can now quit the database session
mysql> \q
> Now, **persist** [innodb_file_per_table](https://dev.mysql.com/doc/refman/5.6/en/tablespace-enabling.html) and [innodb_file_format](https://dev.mysql.com/doc/refman/5.6/en/innodb-file-format-enabling.html) in your `my.cnf` file.
Ensure at this stage that your GitLab instance is indeed **stopped**.
Now, let's convert all the GitLab database tables to the new tablespace format:
mysql > SELECT CONCAT('ALTER TABLE `', TABLE_NAME,'` ENGINE=InnoDB;') AS 'Copy & run these SQL statements:' FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA="gitlabhq_production" AND TABLE_TYPE="BASE TABLE";
#### Check for proper InnoDB File Format, Row Format, Large Prefix and tables conversion
We need to check, enable and probably convert your existing GitLab DB tables to use the [Barracuda InnoDB file format](https://dev.mysql.com/doc/refman/5.6/en/innodb-file-format.html), the [DYNAMIC row format](https://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_dynamic_row_format) and [innodb_large_prefix](http://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_large_prefix) as a second prerequisite for supporting **utfb8mb4 with long indexes** used by recent GitLab databases.
> Now, ensure that [innodb_file_format](https://dev.mysql.com/doc/refman/5.6/en/tablespace-enabling.html) and [innodb_large_prefix](http://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_large_prefix) are **persisted** in your `my.cnf` file.
#### Tables and data conversion to utf8mb4
Now that you have a persistent MySQL setup, you can safely upgrade tables after setup or upgrade time:
# Convert tables not using ROW_FORMAT DYNAMIC:
mysql> SELECT CONCAT('ALTER TABLE `', TABLE_NAME,'` ROW_FORMAT=DYNAMIC;') AS 'Copy & run these SQL statements:' FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA="gitlabhq_production" AND TABLE_TYPE="BASE TABLE" AND ROW_FORMAT!="Dynamic";
# !! If previous query returned results, copy & run all shown SQL statements
# Convert tables/columns not using utf8mb4/utf8mb4_general_ci as encoding/collation:
mysql > SET foreign_key_checks = 0;
mysql > SELECT CONCAT('ALTER TABLE `', TABLE_NAME,'` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;') AS 'Copy & run these SQL statements:' FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA="gitlabhq_production" AND TABLE_COLLATION != "utf8mb4_general_ci" AND TABLE_TYPE="BASE TABLE";
# !! If previous query returned results, copy & run all shown SQL statements