What causes "Master Node Not Enumerated" in redis/node-redis?

Run `sentinel masters` on a reachable sentinel and confirm options.name is listed with valid host/port.

redis/node-redis · error · Error

Master Node Not Enumerated

Error message

Master Node Not Enumerated

What it means

Thrown by RedisSentinelFactory.getMasterNode() when `connected` is true (at least one sentinel accepted a connection) but parseNode(masterData) returned undefined for every sentinel tried (sentinel/index.ts:1757). So the sentinels are reachable but none could resolve a valid master for options.name — the master name is unknown to them or its record is unparseable.

Source

Thrown at packages/client/lib/sentinel/index.ts:1758

      connected = true;

      try {
        const masterData = await client.sentinel.sentinelMaster(this.options.name);

        const master = parseNode(masterData);
        if (master === undefined) {
          continue;
        }

        return master;
      } finally {
        client.destroy();
      }
    }

    if (connected) {
      throw new Error("Master Node Not Enumerated");
    }

    throw new Error("couldn't connect to any sentinels");
  }

  async getMasterClient() {
    const master = await this.getMasterNode();
    const socket = getMappedNode(master.host, master.port, this.options.nodeAddressMap);
    return RedisClient.create({
      ...this.options.nodeClientOptions,
      socket: {
        ...this.options.nodeClientOptions?.socket,
        host: socket.host,
        port: socket.port
      }
    });
  }

View on GitHub (pinned to bb5beb5657)

Solutions

Run `sentinel masters` on a reachable sentinel and confirm options.name is listed with valid host/port.
Fix the master name in RedisSentinelFactory options to match sentinel.conf exactly (case-sensitive).
If the master record is malformed, check the sentinel health/version and re-add the monitor (`SENTINEL MONITOR`).

Defensive patterns

Strategy: validation

Validate before calling

// Confirm a reachable sentinel knows the master name before calling getMasterNode().
async function assertMasterKnown(sentinelNode, name) {
  const c = createClient({ socket: sentinelNode });
  c.on('error', () => {});
  await c.connect();
  try {
    const masters = await c.sentinel.sentinelMasters();
    const m = masters.find(x => x.name === name);
    if (!m || !m.host || !m.port) throw new Error(`sentinel has no valid master for '${name}'`);
  } finally {
    await c.destroy();
  }
}

Try / catch

try {
  const master = await factory.getMasterNode();
} catch (e) {
  if (e instanceof Error && /Master Node Not Enumerated/.test(e.message)) {
    // master name mismatch — recheck options.name against sentinel.conf
  }
  throw e;
}

Prevention

Source options.name from the same config as the sentinel's monitor directive.
Run `SENTINEL MASTERS` during deploys to confirm the name/host/port are present.
Centralize master-name config so client and sentinel cannot drift.

When it happens

Trigger: Calling getMasterNode() with options.name that the reachable sentinels do not monitor; sentinel returns a master record missing host/port or flagged such that parseNode rejects it.

Common situations: Mismatched master name between client config and sentinel.conf; pointing at a sentinel pool for a different deployment; sentinel recently reconfigured and the master record is empty.

Related errors

AI-assisted analysis of redis/node-redis@bb5beb5657 (2026-08-03). Data as JSON: /data/errors/95df6e12348c0a3c.json. Report an issue: GitHub.