# add-aggregator

## Description

Add an aggregator node to the cluster.

This command must be run from the same host that the master aggregator is currently running on.

After `memsqlctl` connects to the node specified by the user, it runs the query `ADD AGGREGATOR user:password@host:port` on the master aggregator.

The `--password` flag is required and specifies the SingleStore`root` password. You can use this flag in conjunction with the `--user` flag to specify a SingleStore user that is different from the `root` user and the user’s password.

Note that the `MEMSQL_PASSWORD` environment variable is a safer alternative option for setting the password.

Wrap the password in single quotes (') to avoid having special characters included in the password interpreted by the shell. For example: `sdb-admin add-aggregator --port 3306 --password '<<fooismypassword'`

## Usage

```
Usage:
  memsqlctl add-aggregator [flags]

Flags:
  -h, --help                             Help for add-aggregator
      --host string                      The cluster-addressable hostname for the node
  -p, --password STRING                  The database user's password
      --port PORT                        The cluster-addressable port for the node (default 3306)
      --role {follower, voting_member}   The role that an aggregator will be assigned when added.
                                         This option identifies whether the added aggregator will be a candidate for Master Aggregator failover.
                                         Possible roles are voting_member and follower. The default value is follower. (default follower)
      --user string                      The database user (default "root")

Global Flags:
  -c, --config FILE_PATH                     Path to the memsqctl config file
      --default-install-dir DIRECTORY_PATH   Path to the default install directory
      --insecure-ssl                         Fall back to insecure SSL connections to local nodes if memsqlctl is unable to otherwise establish a connection (ADVANCED)
  -j, --json                                 Print output in JSON format
      --node-metadata-file FILE_PATH         Path to the node metadata file
      --parallelism POSITIVE_INTEGER         Maximum amount of operations to be run in parallel
      --ssl-ca FILE_PATH                     The path to the CA certificate file (in PEM format) to authenticate the database certificate
      --timeout duration                     Maximum time for operation to complete (e.g., 30s, 10m, 1.5h)
      --verbose-json                         Print output in JSON format, include some warnings and user messages
  -v, --verbosity count                      Increase logging verbosity
  -y, --yes                                  Enable non-interactive mode and assume the user would like to move forward with the proposed actions by default
```

## Remarks

* This command is interactive unless you use either `--yes` or `--json` flag to override interactive behavior.
* The `memsqlctl add-aggregator` command is equivalent to the [sdb-admin add-aggregator](https://docs.singlestore.com/db/v9.1/reference/singlestore-tools-reference/sdb-admin-commands/add-aggregator.md) command.

## Output

The following is the standard output for the `add-aggregator` command.

```shell
sudo memsqlctl add-aggregator --host "172.17.0.6"

```

```output

memsqlctl will perform the following actions on the local master aggregator on port 3306:
  · Run `ADD AGGREGATOR root:@172.17.0.6:3306`

Would you like to continue? [y/N]: y
✓ Added aggregator 172.17.0.6:3306 to cluster

```

***

Modified at: January 13, 2026

Source: [/db/v9.1/reference/singlestore-tools-reference/memsqlctl-commands/add-aggregator/](https://docs.singlestore.com/db/v9.1/reference/singlestore-tools-reference/memsqlctl-commands/add-aggregator/)

(An index of the documentation is available at /llms.txt)