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:

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

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

    $ openstack database 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 openstack database 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 openstack database configuration create command. The general syntax for this command is:

    $ openstack database configuration create NAME VALUES --datastore DATASTORE_NAME --datastore-version DATASTORE_VERSION_NAME
    
    • NAME. The name you want to use for this group.

    • VALUES. The list of key-value pairs. Set VALUES as a JSON dictionary, for example:

      {"myFirstKey" : "someString", "mySecondKey" : 1}
      
    • DATASTORE_NAME. The name of the associated data store.

    • DATASTORE_VERSION_NAME. The name of the associated data store version

    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.

    $ openstack database configuration create group1 '{"sync_binlog" : 1}' --datastore mysql --datastore-version mysql-5.5
    +----------------------+--------------------------------------+
    |       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 openstack database 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:

    $ openstack database instance 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:

    $ openstack database 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.

    $ openstack database 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 openstack database configuration detach command.

  • Modify a configuration group on the fly, using the openstack database configuration parameter set command.

  • Find out what instances are using a configuration group, using the openstack database configuration instances command.

  • Delete a configuration group, using the openstack database configuration delete command. You might want to do this if no instances use a group.