The Ultimate Guide to High Availability with MariaDB

Server Resource

Server Resource

A server resource represents a backend database server.

Resource Operations

The :name in all of the URIs must be the name of a server in MaxScale.

Get a server

GET /v1/servers/:name

Get a single server.

Response

Status: 200 OK

{
    "data": {
        "attributes": {
            "gtid_binlog_pos": "0-3000-9",
            "gtid_current_pos": "0-3000-9",
            "last_event": "server_down",
            "lock_held": null,
            "master_group": null,
            "master_id": -1,
            "name": "server1",
            "node_id": 3000,
            "parameters": {
                "address": "127.0.0.1",
                "disk_space_threshold": null,
                "extra_port": 0,
                "monitorpw": null,
                "monitoruser": null,
                "persistmaxtime": 0,
                "persistpoolmax": 0,
                "port": 3000,
                "priority": 0,
                "proxy_protocol": false,
                "rank": "primary",
                "socket": null,
                "ssl": false,
                "ssl_ca_cert": null,
                "ssl_cert": null,
                "ssl_cert_verify_depth": 9,
                "ssl_cipher": null,
                "ssl_key": null,
                "ssl_verify_peer_certificate": false,
                "ssl_verify_peer_host": false,
                "ssl_version": "MAX"
            },
            "read_only": false,
            "replication_lag": 0,
            "server_id": 3000,
            "slave_connections": [],
            "state": "Master, Running",
            "statistics": {
                "active_operations": 0,
                "adaptive_avg_select_time": "0ns",
                "connection_pool_empty": 0,
                "connections": 1,
                "max_connections": 1,
                "max_pool_size": 0,
                "persistent_connections": 0,
                "reused_connections": 0,
                "routed_packets": 0,
                "total_connections": 1
            },
            "triggered_at": "Thu, 20 Jul 2023 07:28:41 GMT",
            "version_string": "10.5.19-MariaDB-1:10.5.19+maria~ubu2004-log"
        },
        "id": "server1",
        "links": {
            "self": "http://localhost:8989/v1/servers/server1"
        },
        "relationships": {
            "monitors": {
                "data": [
                    {
                        "id": "MariaDB-Monitor",
                        "type": "monitors"
                    }
                ],
                "links": {
                    "related": "http://localhost:8989/v1/monitors/",
                    "self": "http://localhost:8989/v1/servers/server1/relationships/monitors"
                }
            },
            "services": {
                "data": [
                    {
                        "id": "RW-Split-Router",
                        "type": "services"
                    },
                    {
                        "id": "Read-Connection-Router",
                        "type": "services"
                    }
                ],
                "links": {
                    "related": "http://localhost:8989/v1/services/",
                    "self": "http://localhost:8989/v1/servers/server1/relationships/services"
                }
            }
        },
        "type": "servers"
    },
    "links": {
        "self": "http://localhost:8989/v1/servers/server1"
    }
}

Get all servers

GET /v1/servers

Response

Response contains a resource collection with all servers.

Status: 200 OK

{
    "data": [
        {
            "attributes": {
                "gtid_binlog_pos": "0-3000-9",
                "gtid_current_pos": "0-3000-9",
                "last_event": "server_down",
                "lock_held": null,
                "master_group": null,
                "master_id": -1,
                "name": "server1",
                "node_id": 3000,
                "parameters": {
                    "address": "127.0.0.1",
                    "disk_space_threshold": null,
                    "extra_port": 0,
                    "monitorpw": null,
                    "monitoruser": null,
                    "persistmaxtime": 0,
                    "persistpoolmax": 0,
                    "port": 3000,
                    "priority": 0,
                    "proxy_protocol": false,
                    "rank": "primary",
                    "socket": null,
                    "ssl": false,
                    "ssl_ca_cert": null,
                    "ssl_cert": null,
                    "ssl_cert_verify_depth": 9,
                    "ssl_cipher": null,
                    "ssl_key": null,
                    "ssl_verify_peer_certificate": false,
                    "ssl_verify_peer_host": false,
                    "ssl_version": "MAX"
                },
                "read_only": false,
                "replication_lag": 0,
                "server_id": 3000,
                "slave_connections": [],
                "state": "Master, Running",
                "statistics": {
                    "active_operations": 0,
                    "adaptive_avg_select_time": "0ns",
                    "connection_pool_empty": 0,
                    "connections": 1,
                    "max_connections": 1,
                    "max_pool_size": 0,
                    "persistent_connections": 0,
                    "reused_connections": 0,
                    "routed_packets": 0,
                    "total_connections": 1
                },
                "triggered_at": "Thu, 20 Jul 2023 07:28:41 GMT",
                "version_string": "10.5.19-MariaDB-1:10.5.19+maria~ubu2004-log"
            },
            "id": "server1",
            "links": {
                "self": "http://localhost:8989/v1/servers/server1"
            },
            "relationships": {
                "monitors": {
                    "data": [
                        {
                            "id": "MariaDB-Monitor",
                            "type": "monitors"
                        }
                    ],
                    "links": {
                        "related": "http://localhost:8989/v1/monitors/",
                        "self": "http://localhost:8989/v1/servers/server1/relationships/monitors"
                    }
                },
                "services": {
                    "data": [
                        {
                            "id": "RW-Split-Router",
                            "type": "services"
                        },
                        {
                            "id": "Read-Connection-Router",
                            "type": "services"
                        }
                    ],
                    "links": {
                        "related": "http://localhost:8989/v1/services/",
                        "self": "http://localhost:8989/v1/servers/server1/relationships/services"
                    }
                }
            },
            "type": "servers"
        },
        {
            "attributes": {
                "gtid_binlog_pos": "0-3000-9",
                "gtid_current_pos": "0-3000-9",
                "last_event": "server_down",
                "lock_held": null,
                "master_group": null,
                "master_id": 3000,
                "name": "server2",
                "node_id": 3001,
                "parameters": {
                    "address": "127.0.0.1",
                    "disk_space_threshold": null,
                    "extra_port": 0,
                    "monitorpw": null,
                    "monitoruser": null,
                    "persistmaxtime": 0,
                    "persistpoolmax": 0,
                    "port": 3001,
                    "priority": 0,
                    "proxy_protocol": false,
                    "rank": "primary",
                    "socket": null,
                    "ssl": false,
                    "ssl_ca_cert": null,
                    "ssl_cert": null,
                    "ssl_cert_verify_depth": 9,
                    "ssl_cipher": null,
                    "ssl_key": null,
                    "ssl_verify_peer_certificate": false,
                    "ssl_verify_peer_host": false,
                    "ssl_version": "MAX"
                },
                "read_only": false,
                "replication_lag": 0,
                "server_id": 3001,
                "slave_connections": [
                    {
                        "connection_name": "",
                        "gtid_io_pos": "",
                        "last_io_error": "",
                        "last_sql_error": "",
                        "master_host": "127.0.0.1",
                        "master_port": 3000,
                        "master_server_id": 3000,
                        "seconds_behind_master": 0,
                        "slave_io_running": "Yes",
                        "slave_sql_running": "Yes"
                    }
                ],
                "state": "Slave, Running",
                "statistics": {
                    "active_operations": 0,
                    "adaptive_avg_select_time": "0ns",
                    "connection_pool_empty": 0,
                    "connections": 1,
                    "max_connections": 1,
                    "max_pool_size": 0,
                    "persistent_connections": 0,
                    "reused_connections": 0,
                    "routed_packets": 2,
                    "total_connections": 1
                },
                "triggered_at": "Thu, 20 Jul 2023 07:28:41 GMT",
                "version_string": "10.5.19-MariaDB-1:10.5.19+maria~ubu2004-log"
            },
            "id": "server2",
            "links": {
                "self": "http://localhost:8989/v1/servers/server2"
            },
            "relationships": {
                "monitors": {
                    "data": [
                        {
                            "id": "MariaDB-Monitor",
                            "type": "monitors"
                        }
                    ],
                    "links": {
                        "related": "http://localhost:8989/v1/monitors/",
                        "self": "http://localhost:8989/v1/servers/server2/relationships/monitors"
                    }
                },
                "services": {
                    "data": [
                        {
                            "id": "RW-Split-Router",
                            "type": "services"
                        },
                        {
                            "id": "Read-Connection-Router",
                            "type": "services"
                        }
                    ],
                    "links": {
                        "related": "http://localhost:8989/v1/services/",
                        "self": "http://localhost:8989/v1/servers/server2/relationships/services"
                    }
                }
            },
            "type": "servers"
        }
    ],
    "links": {
        "self": "http://localhost:8989/v1/servers/"
    }
}

Create a server

POST /v1/servers

Create a new server by defining the resource. The posted object must define at least the following fields.

  • data.id

  • Name of the server

  • data.type

  • Type of the object, must be servers

  • data.attributes.parameters.address OR data.attributes.parameters.socket

  • The address or socket to use. Only one of the fields can be defined.

  • data.attributes.parameters.port

  • The port to use. Needs to be defined if the address field is defined.

The following is the minimal required JSON object for defining a new server.

{
    "data": {
        "id": "server3",
        "type": "servers",
        "attributes": {
            "parameters": {
                "address": "127.0.0.1",
                "port": 3003
            }
        }
    }
}

The relationships of a server can also be defined at creation time. This allows new servers to be created and immediately taken into use.

{
    "data": {
        "id": "server4",
        "type": "servers",
        "attributes": {
            "parameters": {
                "address": "127.0.0.1",
                "port": 3002
            }
        },
        "relationships": {
            "services": {
                "data": [
                    {
                        "id": "RW-Split-Router",
                        "type": "services"
                    },
                    {
                        "id": "Read-Connection-Router",
                        "type": "services"
                    }
                ]
            },
            "monitors": {
                "data": [
                    {
                        "id": "MySQL-Monitor",
                        "type": "monitors"
                    }
                ]
            }
        }
    }
}

Refer to the Configuration Guide for a full list of server parameters.

Response

Server created:

Status: 204 No Content

Invalid JSON body:

Status: 403 Forbidden

Update a server

PATCH /v1/servers/:name

The request body must be a valid JSON document representing the modified server.

Modifiable Fields

In addition to the server parameters, the services and monitors fields of the relationships object can be modified. Removal, addition and modification of the links will change which service and monitors use this server.

For example, removing the first value in the services list in the relationships object from the following JSON document will remove the server1 from the service RW-Split-Router.

Removing a service from a server is analogous to removing the server from the service. Both unlink the two objects from each other.

Request for PATCH /v1/servers/server1 that modifies the address of the server:

{
    "data": {
        "attributes": {
            "parameters": {
                "address": "192.168.0.123"
            }
        }
    }
}

Request for PATCH /v1/servers/server1 that modifies the server relationships:

{
    "data": {
        "relationships": {
            "services": {
                "data": [
                    { "id": "Read-Connection-Router", "type": "services" }
                ]
            },
            "monitors": {
                "data": [
                    { "id": "MySQL-Monitor", "type": "monitors" }
                ]
            }
        }
    }
}

If parts of the resource are not defined (e.g. the attributes field in the above example), those parts of the resource are not modified. All parts that are defined are interpreted as the new definition of those part of the resource. In the above example, the relationships of the resource are completely redefined.

Response

Server modified:

Status: 204 No Content

Invalid JSON body:

Status: 403 Forbidden

Update server relationships

PATCH /v1/servers/:name/relationships/:type

The :type in the URI must be either services, for service relationships, or monitors, for monitor relationships.

The request body must be a JSON object that defines only the data field. The value of the data field must be an array of relationship objects that define the id and type fields of the relationship. This object will replace the existing relationships of the particular type from the server.

The following is an example request and request body that defines a single service relationship for a server.

PATCH /v1/servers/my-db-server/relationships/services

{
    data: [
          { "id": "my-rwsplit-service", "type": "services" }
    ]
}

All relationships for a server can be deleted by sending an empty array as the data field value. The following example removes the server from all services.

PATCH /v1/servers/my-db-server/relationships/services

{
    data: []
}

Response

Server relationships modified:

Status: 204 No Content

Invalid JSON body:

Status: 403 Forbidden

Destroy a server

DELETE /v1/servers/:name

A server can only be deleted if it is not used by any services or monitors.

This endpoint also supports the force=yes parameter that will unconditionally delete the server by first unlinking it from all services and monitors that use it.

Response

Server is destroyed:

Status: 204 No Content

Server is in use:

Status: 403 Forbidden

Set server state

PUT /v1/servers/:name/set

This endpoint requires that the state parameter is passed with the request. The value of state must be one of the following values.

Value State Description
master Server is a Master
slave Server is a Slave
maintenance Server is put into maintenance
running Server is up and running
synced Server is a Galera node
drain Server is drained of connections

For example, to set the server db-server-1 into maintenance mode, a request to the following URL must be made:

PUT /v1/servers/db-server-1/set?state=maintenance

This endpoint also supports the force=yes parameter that will cause all connections to the server to be closed if state=maintenance is also set. By default setting a server into maintenance mode will cause connections to be closed only after the next request is sent.

The following example forcefully closes all connections to server db-server-1 and sets it into maintenance mode:

PUT /v1/servers/db-server-1/set?state=maintenance&force=yes

Response

Server state modified:

Status: 204 No Content

Missing or invalid parameter:

Status: 403 Forbidden

Clear server state

PUT /v1/servers/:name/clear

This endpoint requires that the state parameter is passed with the request. The value of state must be one of the values defined in the set endpoint documentation.

Response

Server state modified:

Status: 204 No Content

Missing or invalid parameter:

Status: 403 Forbidden

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