MariaDB Enterprise ColumnStore Removing a Node

Unlink from Service in MaxScale

The server object for the node must be unlinked from the service using MaxScale's REST API:

• Unlink the server object from the service using the unlink service command

• As the first argument, provide the name of the service

• As the second argument, provide the name of the server

$ maxctrl unlink service \
   mcs_service \
   mcs3

Check the Service in MaxScale

To confirm that the server object was properly unlinked from the service, the service should be checked using MaxScale's REST API:

• Show the services using the show services command

For example:

$ maxctrl show services

Unlink from Monitor in MaxScale

The server object for the node must be unlinked from the monitor using MaxScale's REST API:

• Unlink a server object from the monitor using the unlink monitor command

• As the first argument, provide the name of the monitor

• As the second argument, provide the name of the server

$ maxctrl unlink monitor \
   mcs_monitor \
   mcs3

Check the Monitor in MaxScale

To confirm that the server object was properly unlinked from the monitor, the monitor should be checked using MaxScale's REST API:

• Show the monitors using the show monitors command

For example:

$ maxctrl show monitors

Remove the Server from MaxScale

The server object for the node must also be removed from MaxScale using MaxScale's REST API:

• Use MaxCtrl or another supported REST client

• Remove the server object using the destroy server command

• As the first argument, provide the name for the server

For example:

$ maxctrl destroy server \
   mcs3

Check the Server in MaxScale

To confirm that the server object was properly removed, the server objects should be checked using MaxScale's REST API:

• Show the server objects using the show servers command

For example:

$ maxctrl show servers

Stop the Enterprise ColumnStore Services

The Enterprise Server. Enterprise ColumnStore, and CMAPI services can be stopped using the systemctl command.

Perform the following procedure on the node:

1. Stop the MariaDB Enterprise Server service:

   $ sudo systemctl stop mariadb
   

2. Stop the MariaDB Enterprise ColumnStore service:

   $ sudo systemctl stop mariadb-columnstore
   

3. Stop the CMAPI service:

   $ sudo systemctl stop mariadb-columnstore-cmapi
   

Remove the Node from Enterprise ColumnStore

The node must be removed from Enterprise ColumnStore using CMAPI:

• Remove the node using the remove-node endpoint path

• Use a supported REST client, such as curl

• Format the JSON output using jq for enhanced readability

• Authenticate using the configured API key

• Include the required headers

For example, if the primary node's host name is mcs1 and the IP address for the node to remove is 192.0.2.3:

• In ES 10.5.10-7 and later:

  $ curl -k -s -X DELETE https://mcs1:8640/cmapi/0.4.0/cluster/node \
     --header 'Content-Type:application/json' \
     --header 'x-api-key:93816fa66cc2d8c224e62275bd4f248234dd4947b68d4af2b29671dd7d5532dd' \
     --data '{"timeout":20, "node": "192.0.2.3"}' \
     | jq .
  

• In ES 10.5.9-6 and earlier:

  $ curl -k -s -X PUT https://mcs1:8640/cmapi/0.4.0/cluster/remove-node \
     --header 'Content-Type:application/json' \
     --header 'x-api-key:93816fa66cc2d8c224e62275bd4f248234dd4947b68d4af2b29671dd7d5532dd' \
     --data '{"timeout":20, "node": "192.0.2.3"}' \
     | jq .
  

Example output:

{
  "timestamp": "2020-10-28 00:39:14.672142",
  "node_id": "192.0.2.3"
}

Check Enterprise ColumnStore Status

To confirm that the node was properly removed, the status of Enterprise ColumnStore should be checked using CMAPI:

• Check the status using the status endpoint path

For example, if the primary node's host name is mcs1:

$ curl -k -s https://mcs1:8640/cmapi/0.4.0/cluster/status \
   --header 'Content-Type:application/json' \
   --header 'x-api-key:93816fa66cc2d8c224e62275bd4f248234dd4947b68d4af2b29671dd7d5532dd' \
   | jq .

Example output:

{
  "timestamp": "2020-12-15 00:40:34.353574",
  "192.0.2.1": {
    "timestamp": "2020-12-15 00:40:34.362374",
    "uptime": 11467,
    "dbrm_mode": "master",
    "cluster_mode": "readwrite",
    "dbroots": [
      "1"
    ],
    "module_id": 1,
    "services": [
      {
        "name": "workernode",
        "pid": 19202
      },
      {
        "name": "controllernode",
        "pid": 19232
      },
      {
        "name": "PrimProc",
        "pid": 19254
      },
      {
        "name": "ExeMgr",
        "pid": 19292
      },
      {
        "name": "WriteEngine",
        "pid": 19316
      },
      {
        "name": "DMLProc",
        "pid": 19332
      },
      {
        "name": "DDLProc",
        "pid": 19366
      }
    ]
  },
  "192.0.2.2": {
    "timestamp": "2020-12-15 00:40:34.428554",
    "uptime": 11437,
    "dbrm_mode": "slave",
    "cluster_mode": "readonly",
    "dbroots": [
      "2"
    ],
    "module_id": 2,
    "services": [
      {
        "name": "workernode",
        "pid": 17789
      },
      {
        "name": "PrimProc",
        "pid": 17813
      },
      {
        "name": "ExeMgr",
        "pid": 17854
      },
      {
        "name": "WriteEngine",
        "pid": 17877
      }
    ]
  },
  "num_nodes": 2
}