MariaDb on Documentation

Backup

Mon, 01 Jan 0001 00:00:00 +0000

Mariabackup is used to create backups.

CCX backups the Primary server. In multi-primary setups the node with the highest wsrep_local_index is elected.

Backups are streamed directly to S3 staroge.

Mariabackup blocks DDL operations during the backup using the --lock-ddl flag. Any attempt to CREATE, ALTER, DROP, TRUNCATE a table during backup creation will be locked with the status Waiting for backup lock (see SHOW FULL PROCESSLIST). In this case, wait for the backup to finish and, perform the operation later.

Configuration

Mon, 01 Jan 0001 00:00:00 +0000

max_connections

75 connections / GB of RAM.
Example: 4GB of RAM yields 300 connections.
This setting cannot be changed as it affects system stability.

InnoDB settings

These setting cannot be changed as it affects system stability.

innodb_buffer_pool_size

50% of RAM if total RAM is > 4GB
25% of RAM if total RAM is <= 4GB

innodb_log_file_size

1024 MB if innodb_buffer_pool_size >= 8192MB
512 MB if innodb_buffer_pool_size < 8192MB

innodb_buffer_pool_instances

InnoDB options

variable_name	variable_value
innodb_buffer_pool_size	Depends on instance size
innodb_flush_log_at_trx_commit	2
innodb_file_per_table	1
innodb_data_file_path	Depends on instance
innodb_read_io_threads	4
innodb_write_io_threads	4
innodb_doublewrite	1
innodb_buffer_pool_instances	Depends on instance size
innodb_redo_log_capacity	8G
innodb_thread_concurrency	0
innodb_flush_method	O_DIRECT
innodb_autoinc_lock_mode	2
innodb_stats_on_metadata	0
default_storage_engine	innodb

General options

variable_name	variable_value
tmp_table_size	64M
max_heap_table_size	64M
max_allowed_packet	1G
sort_buffer_size	256K
read_buffer_size	256K
read_rnd_buffer_size	512K
memlock	0
sysdate_is_now	1
max_connections	Depends on instance size
thread_cache_size	512
table_open_cache	4000
table_open_cache_instances	16
lower_case_table_names	0

Storage

Recommended storage size

We recommend a maximum of 100GB storage per GB of RAM.
Example: 4GB of RAM yields 400GB of storage.
The recommendation is not enforced by the CCX platform.

Importing Data

Mon, 01 Jan 0001 00:00:00 +0000

This procedure describes how to import data to a MariaDB datastore located in CCX.

The MariaDB Datastore on CCX is denoted as the ‘replica’
The source of the data is denoted as the ‘source’

note:

If you do not want to setup replication, then you can chose to only apply the sections:

Create a database dump file

Apply the dumpfile on the replica

Limitations of MariaDB

MariaDB does not offer as fine grained control over privileges as MySQL. Nor does it have the same level of replication features.

Limitations

Mon, 01 Jan 0001 00:00:00 +0000

Every product has limitations. Here is a list MariaDB limitations:

Permissions

The privilege system is not as flexible as in MySQL.

The ‘ccxadmin’ user has the following privileges:

Global / all databases (.):

CREATE USER, REPLICATION SLAVE, REPLICATION SLAVE ADMIN, SLAVE MONITOR

On databases created from CCX, the admin user can create new users and grant privileges:

ALL PRIVILEGES WITH GRANT OPTION

This means that users can only create databases from the CCX UI. Once the database has been created from the CCX UI, then the ccxadmin user can create users and grant user privileges on the database using MariaDB CLI.

Overview

Mon, 01 Jan 0001 00:00:00 +0000

CCX supports two types of MariaDB clustering:

MariaDB Replication (Primary-replica configuration)x
MariaDB Cluster (Multi-primary configuration)

For general purpose applications we recommend using MariaDB Replication, and we only recommend to use MariaDB Cluster if you are migrating from an existing application that uses MariaDB Cluster.

If you are new to MariaDB Cluster we stronly recommend to read about the MariaDB Cluster 10.x limitations and MariaDB Cluster Overview to understand if your application can benefit from MariaDB Cluster.

Restore

Mon, 01 Jan 0001 00:00:00 +0000

There are two options to restore a backup:

Restore a backup on the existing datastore
Restore a backup on a new datastore

Please note that restoring a backup may be a long running process.

This option allows to restore a backup with point in time recovery. The WAL logs are replayed until the desired PITR.

Warning! Running several restores may change the timelines.

This option allows to restore a backup on a new datastore. This option does not currently support PITR.

TLS Connection

Mon, 01 Jan 0001 00:00:00 +0000

SSL Modes

CCX currently supports connections to MariaDB in two SSL modes:

REQUIRED: This mode requires an SSL connection. If a client attempts to connect without SSL, the server rejects the connection.
VERIFY_CA: This mode requires an SSL connection and the server must verify the client’s certificate against the CA certificates that it has.

CA Certificate

The Certificate Authority (CA) certificate required for VERIFY_CA mode can be downloaded from your datastore on CCX using an API call or through the user interface on page https://{your_ccx_domain}/projects/default/data-stores/{datastore_id}/settings. This certificate is used for the VERIFY_CA SSL mode.