Description MySQL

Technical Specifications

The available MySQL versions are 5.7 and 8.0.

Fixed and custom node configurations are available for creating a database cluster.

Fixed configurations with a predefined amount of resources:

  • 2 vCPU, 4 GB RAM, 32 GB local disk;
  • 2 vCPU, 8 GB RAM, 64 GB local disk;
  • 4 vCPU, 16 GB RAM, 128 GB local disk;
  • 8 vCPU, 32 GB RAM, 256 GB local disk;
  • 16 vCPU, 64 GB RAM, 512 GB local disk;
  • 32 vCPU, 128 GB RAM, 1024 GB local disk.

In custom configurations, you can select the amount of resources:

  • vCPU — from 1 to 8 cores;
  • RAM — from 4 GB to 64 GB;
  • local disk — from 15 GB to 512 GB.

Please note that about 5 GB is reserved on the local disk for the operating system, service components, and log storage. The rest of the volume is available for hosting databases.

The following clusters are available for creation:

  • consisting only of the master;
  • consisting of a master and 2 replicas.

Percona XtraDB Cluster is used for creating a database cluster from multiple nodes. Learn more about limitations in MySQL limitations.

You can create MySQL clusters on both private and public subnets. You cannot use the floating IP.

The configurations (the number of cores, RAM, and local SSD) are available on our website.

You can scale the cluster horizontally (change the number of replicas) or vertically (change the configuration) at any time. In vertical scaling, you can only select configurations with the same or larger disk size.

The backup is performed automatically. You can restore your cluster from a backup to any point in the last 7 days. Learn more about backups.

If the master node is unavailable for some reason, the master role will be assigned to the synchronous replica. A new node will be created instead of a failed one, and it will take the role of a replica. If a replica fails, a new replica will be created instead.

The monitoring of the following main indicators of the cluster operation service is implemented in MySQL clusters — vCPU load, RAM, and SSD. In addition, the history of operations and notifications about the cluster disk fullness are available in the cluster. Learn more about monitoring.

DBMS Settings

DBMS settings are selected specifically to ensure high database performance. The settings parameters depend on the selected computing resources configuration for the database cluster.

If the database cluster configuration is changed, the following parameters will be also changed automatically:

innodb_buffer_pool_size
innodb_log_file_size
innodb_buffer_pool_instances
thread_pool_size
max_heap_table_size
tmp_table_size
temptable_max_ram

utf8mb4 is used as the character set (CHARSET).

As COLLATION are used:

  • utf8mb4_general_ci for mysql 5.7
  • utf8mb4_0900_ai_ci for mysql 8

These are the default options. You can change the CHARSET and COLLATION values when creating objects.

Authentication plugin (default_authentication_plugin):

  • mysql_native_password for mysql 5.7
  • caching_sha2_password for mysql 8

How It Works

To create a cluster, you need to select:

  • name;
  • region;
  • DBMS version;
  • node configuration;
  • the number of replicas (if the cluster is fault tolerant);
  • the subnet where the cluster will be created.

After the creation process starts, a new cluster will appear in the interface. You can manage your cluster on its page, which will become available after the cluster status changes to Active.

Only the cluster itself is available to users — there is no access to the cluster nodes, since they are on the Selectel side.

All the functionality for managing the cluster is inside it. From the cluster page, you can create databases, users, assign access rights, and scale the cluster.

To work with databases, you need to create users and provide them with access to these databases. When connecting to the cluster, you need to provide the database name, username, password, and cluster port and addresses. Learn more about connecting to a cluster.

All users in the cluster have the same rights.