openstack-manuals/doc/user-guide/source/manage-db-config.rst

Manage database configuration

You can manage database configuration tasks by using configuration groups. Configuration groups let you set configuration options, in bulk, on one or more databases.

This example assumes you have created a MySQL database and shows you how to use a configuration group to configure it. Although this example sets just one option on one database, you can use these same procedures to set multiple options on multiple database instances throughout your environment. This can provide significant time savings in managing your cloud.

Bulk-configure a database or databases

1. List available options

   First, determine which configuration options you can set. Different data store versions have different configuration options.

   List the names and IDs of all available versions of the mysql data store:

   $ trove datastore-version-list mysql
   
   +--------------------------------------+-----------+
   |                  id                  |    name   |
   +--------------------------------------+-----------+
   | eeb574ce-f49a-48b6-820d-b2959fcd38bb | mysql-5.5 |
   +--------------------------------------+-----------+

   Pass in the data store version ID with the trove configuration-parameter-list command to get the available options:

   $ trove configuration-parameter-list DATASTORE_VERSION_ID
   
   +--------------------------------+---------+---------+----------------------+------------------+
   |              name              |   type  |   min   |         max          | restart_required |
   +--------------------------------+---------+---------+----------------------+------------------+
   |    auto_increment_increment    | integer |    1    |        65535         |      False       |
   |     auto_increment_offset      | integer |    1    |        65535         |      False       |
   |           autocommit           | integer |    0    |          1           |      False       |
   |    bulk_insert_buffer_size     | integer |    0    | 18446744073709547520 |      False       |
   |      character_set_client      |  string |         |                      |      False       |
   |    character_set_connection    |  string |         |                      |      False       |
   |     character_set_database     |  string |         |                      |      False       |
   |    character_set_filesystem    |  string |         |                      |      False       |
   |     character_set_results      |  string |         |                      |      False       |
   |      character_set_server      |  string |         |                      |      False       |
   |      collation_connection      |  string |         |                      |      False       |
   |       collation_database       |  string |         |                      |      False       |
   |        collation_server        |  string |         |                      |      False       |
   |        connect_timeout         | integer |    1    |        65535         |      False       |
   |        expire_logs_days        | integer |    1    |        65535         |      False       |
   |    innodb_buffer_pool_size     | integer |    0    |     68719476736      |       True       |
   |     innodb_file_per_table      | integer |    0    |          1           |       True       |
   | innodb_flush_log_at_trx_commit | integer |    0    |          2           |      False       |
   |     innodb_log_buffer_size     | integer | 1048576 |      4294967296      |       True       |
   |       innodb_open_files        | integer |    10   |      4294967296      |       True       |
   |   innodb_thread_concurrency    | integer |    0    |         1000         |      False       |
   |      interactive_timeout       | integer |    1    |        65535         |      False       |
   |        join_buffer_size        | integer |    0    |      4294967296      |      False       |
   |        key_buffer_size         | integer |    0    |      4294967296      |      False       |
   |          local_infile          | integer |    0    |          1           |      False       |
   |       max_allowed_packet       | integer |   1024  |      1073741824      |      False       |
   |       max_connect_errors       | integer |    1    | 18446744073709547520 |      False       |
   |        max_connections         | integer |    1    |        65535         |      False       |
   |      max_user_connections      | integer |    1    |        100000        |      False       |
   |    myisam_sort_buffer_size     | integer |    4    | 18446744073709547520 |      False       |
   |           server_id            | integer |    1    |        100000        |       True       |
   |        sort_buffer_size        | integer |  32768  | 18446744073709547520 |      False       |
   |          sync_binlog           | integer |    0    | 18446744073709547520 |      False       |
   |          wait_timeout          | integer |    1    |       31536000       |      False       |
   +--------------------------------+---------+---------+----------------------+------------------+

   In this example, the trove configuration-parameter-list command returns a list of options that work with MySQL 5.5.

2. Create a configuration group

   A configuration group contains a comma-separated list of key-value pairs. Each pair consists of a configuration option and its value.

   You can create a configuration group by using the trove configuration-create command. The general syntax for this command is:

   $ trove configuration-create NAME VALUES --datastore DATASTORE_NAME

   • NAME. The name you want to use for this group.
   • VALUES. The list of key-value pairs.
   • DATASTORE_NAME. The name of the associated data store.

   Set VALUES as a JSON dictionary, for example:

   {"myFirstKey" : "someString", "mySecondKey" : someInt}

   This example creates a configuration group called group1. group1 contains just one key and value pair, and this pair sets the sync_binlog option to 1.

   $ trove configuration-create group1 '{"sync_binlog" : 1}' --datastore mysql
   
   +----------------------+--------------------------------------+
   |       Property       |                Value                 |
   +----------------------+--------------------------------------+
   | datastore_version_id | eeb574ce-f49a-48b6-820d-b2959fcd38bb |
   |     description      |                 None                 |
   |          id          | 9a9ef3bc-079b-476a-9cbf-85aa64f898a5 |
   |         name         |                group1                |
   |        values        |          {"sync_binlog": 1}          |
   +----------------------+--------------------------------------+

3. Examine your existing configuration

   Before you use the newly-created configuration group, look at how the sync_binlog option is configured on your database. Replace the following sample connection values with values that connect to your database:

   $ mysql -u user7 -ppassword -h 172.16.200.2 myDB7
    Welcome to the MySQL monitor. Commands end with ; or \g.
    ...
    mysql> show variables like 'sync_binlog';
    +---------------+-------+
    | Variable_name | Value |
    +---------------+-------+
    | sync_binlog   | 0     |
    +---------------+-------+

   As you can see, the sync_binlog option is currently set to 0 for the myDB7 database.

4. Change the database configuration using a configuration group

   You can change a database's configuration by attaching a configuration group to a database instance. You do this by using the trove configuration-attach command and passing in the ID of the database instance and the ID of the configuration group.

   Get the ID of the database instance:

   $ trove list
   
   +-------------+------------------+-----------+-------------------+--------+-----------+------+
   |     id      |       name       | datastore | datastore_version | status | flavor_id | size |
   +-------------+------------------+-----------+-------------------+--------+-----------+------+
   | 26a265dd... | mysql_instance_7 |   mysql   |     mysql-5.5     | ACTIVE |     6     |  5   |
   +-------------+------------------+-----------+-------------------+--------+-----------+------+

   Get the ID of the configuration group:

   $ trove configuration-list
   
   +-------------+--------+-------------+---------------------+
   |    id       |  name  | description |datastore_version_id |
   +-------------+--------+-------------+---------------------+
   | 9a9ef3bc... | group1 |     None    |      eeb574ce...    |
   +-------------+--------+-------------+---------------------+

   Attach the configuration group to the database instance:

   Note

   This command syntax pertains only to python-troveclient version 1.0.6 and later. Earlier versions require you to pass in the configuration group ID as the first argument.

   $ trove configuration-attach DB_INSTANCE_ID CONFIG_GROUP_ID

5. Re-examine the database configuration

   Display the sync_binlog setting again:

   mysql> show variables like 'sync_binlog';
   +---------------+-------+
   | Variable_name | Value |
   +---------------+-------+
   | sync_binlog   | 1     |
   +---------------+-------+

   As you can see, the sync_binlog option is now set to 1, as specified in the group1 configuration group.

Conclusion. Using a configuration group to set a single option on a single database is obviously a trivial example. However, configuration groups can provide major efficiencies when you consider that:

• A configuration group can specify a large number of option values.
• You can apply a configuration group to hundreds or thousands of database instances in your environment.

Used in this way, configuration groups let you modify your database cloud configuration, on the fly, on a massive scale.

Maintenance. There are also a number of useful maintenance features for working with configuration groups. You can:

• Disassociate a configuration group from a database instance, using the trove configuration-detach command.
• Modify a configuration group on the fly, using the trove configuration-patch command.
• Find out what instances are using a configuration group, using the trove configuration-instances command.
• Delete a configuration group, using the trove configuration-delete command. You might want to do this if no instances use a group.