{
  "port": 1862,
  "protocol": "tcp",
  "service": "MySQL Cluster Manager agent (mcmd)",
  "oneLiner": "The mcmd agent that provisions and controls a MySQL NDB Cluster — an admin plane, not a database.",
  "whatItIs": "MySQL Cluster Manager runs an agent process, `mcmd`, on each cluster host; its `bind_port` defaults to 1862, and the `mcm` client (and a plain `mysql` client pointed at `--port=1862`) connects there to issue cluster commands. Oracle registered the port with IANA in 2009 as \"mysql-cm-agent\". Commands sent over it create and delete clusters, start and stop `ndbd` and `mysqld` processes, and change configuration — so the port belongs to the management plane of an NDB Cluster, distinct from the 3306 data path.",
  "exposure": {
    "verdict": "never",
    "note": "Anything that authenticates to the agent can start, stop, and reconfigure every node in the cluster; keep 1862 on the cluster's private management network and reach it over a VPN or bastion."
  },
  "checkCommand": "mysql -h TARGET -P 1862 --protocol=TCP -u mcmd -p -e 'show status --cluster mycluster;'",
  "links": [
    {
      "title": "MySQL Cluster Manager — mcmd, the MySQL Cluster Manager Agent (default port 1862)",
      "url": "https://dev.mysql.com/doc/mysql-cluster-manager/8.4/en/mcm-using-mcmd.html",
      "kind": "official-docs"
    },
    {
      "title": "IANA port registry — 1862 (mysql-cm-agent)",
      "url": "https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=1862",
      "kind": "iana"
    }
  ]
}