Cluster-in-a-Box CLI Online Deployment - Red Hat Distribution


Installing SingleStore on bare metal, on virtual machines, or in the cloud can be done through the use of popular configuration management tools or through SingleStore’s management tools.

In this guide, you will deploy a SingleStore cluster onto physical or virtual machines and connect to the cluster using a SQL client.

A four-node cluster is the minimal recommended cluster size for showcasing SingleStore as a distributed database with high availability; however, you can use the procedures in this tutorial to scale out to additional nodes for increased performance over large data sets or to handle higher concurrency loads. To learn more about SingleStore’s design principles and topology concepts, see Distributed Architecture.


There are no licensing costs for using up to four license units for the leaf nodes in your cluster. If you need a larger cluster with more/larger leaf nodes, please create an Enterprise License trial key.


For this tutorial you will need:

  • One (for single-host cluster-in-a-box for development) or four physical or virtual machines (hosts) with the following:

    • Each SingleStore node requires at least four (4) x86_64 CPU cores and eight (8) GB of RAM per host

    • Eight (8) vCPU and 32 GB of RAM are recommended for leaf nodes to align with license unit calculations

    • Running a 64-bit version of RHEL/AlmaLinux 7 or later, or Debian 8 or later, with kernel 3.10 or later

    • Port 3306 open on all hosts for intra-cluster communication. Based on the deployment method, this default can be changed either from the command line or via cluster file.

    • Port 8080 open on the main deployment host for the cluster

    • A non-root user with sudo privileges available on all hosts in the cluster that be used to run SingleStore services and own the corresponding runtime state

  • SSH access to all hosts

  • A connection to the Internet to download required packages

If running this in a production environment, it is highly recommended that you follow our host configuration recommendations for optimal cluster performance.

Duplicate Hosts

As of SingleStore Toolbox 1.4.4, a check for duplicate hosts is performed before SingleStore is deployed, and will display a message similar to the following if more than one host has the same SSH host key:

✘ Host check has the same ssh
host keys as, toolbox doesn't support
registering the same host twice

Confirm that all specified hosts are indeed different and aren’t using identical SSH host keys. Identical host keys can be present if you have instantiated your host instances from images (AMIs, snapshots, etc.) that contain existing host keys. When a host is cloned, the host key (typically stored in /etc/ssh/ssh_host_<cipher>_key) will also be cloned.

As each cloned host will have the same host key, an SSH client cannot verify that it is connecting to the intended host. The script that deploys SingleStore will interpret a duplicate host key as an attempt to deploy to the same host twice, and the deployment will fail.

The following steps demonstrate a potential remedy for the duplicate hosts message. Please note these steps may slightly differ depending on your Linux distribution and configuration.

sudo root
ls -al /etc/ssh/
rm /etc/ssh/<your-ssh-host-keys>
ssh-keygen -f /etc/ssh/<ssh-host-key-filename> -N '' -t rsa1
ssh-keygen -f /etc/ssh/<ssh-host-rsa-key-filename> -N '' -t rsa
ssh-keygen -f /etc/ssh/<ssh-host-dsa-key-filename> -N '' -t dsa

For more information about SSH host keys, including the equivalent steps for Ubuntu-based systems, refer to Avoid Duplicating SSH Host Keys.

As of SingleStore Toolbox 1.5.3, sdb-deploy setup-cluster supports an --allow-duplicate-host-fingerprints option that can be used to ignore duplicate SSH host keys.

Network Configuration

Depending on the host and its function in deployment, some or all of the following port settings should be enabled on hosts in your cluster.

These routing and firewall settings must be configured to:

  • Allow database clients (e.g. your application) to connect to the SingleStore aggregators

  • Allow all nodes in the cluster to talk to each other over the SingleStore protocol (3306)

  • Allow you to connect to management and monitoring tools


Default Port





Inbound and Outbound

For host access. Required between nodes in SingleStore tool deployment scenarios. Also useful for remote administration and troubleshooting on the main deployment host.




To get public repo key for package verification. Required for nodes downloading SingleStore APT or YUM packages.



Inbound and Outbound

Default port used by SingleStore. Required on all nodes for intra-cluster communication. Also required on aggregators for client connections.

The service port values are configurable if the default values cannot be used in your deployment environment. For more information on how to change them, see:

We also highly recommend configuring your firewall to prevent other hosts on the Internet from connecting to SingleStore.

Install SingleStore Tools

The first step in deploying your cluster is to download and install the SingleStore Tools on one of the hosts in your cluster. This host will be designated as the main deployment host for deploying SingleStore across your other hosts and setting up your cluster.

These tools perform all major cluster operations including downloading the latest version of SingleStore onto your hosts, assigning and configuring nodes in your cluster, and other management operations. For the purpose of this guide, the main deployment host is the same as the designated Master Aggregator of the SingleStore cluster.

Note: If SingleStore is installed as a sudo user via packages, systemd will automatically start the associated SingleStore processes when a host is rebooted.

Online Installation - Red Hat Distribution

Run the following commands to install SingleStore Tools.

sudo yum-config-manager --add-repo && \
sudo yum install -y singlestoredb-toolbox singlestore-client


If SingleStore Tools cannot be installed using the above commands, verify the following and re-run the above commands to install SingleStore Tools.

  • Verify that the SingleStore repo information is listed under repolist.

    sudo yum repolist
    repo id            repo name            status
    memsql             MemSQL               125
  • Verify that the which package is installed. This is used during the install process to identify the correct package type for your installation.

    rpm -q which
    • If which is not installed, you must install it before proceeding.

      sudo yum install -y which
    • If you cannot install which, you will need to specify the package as rpm during the deployment phase.

  • If you receive an error that the GPG check failed, which resembles the following:

    Importing GPG key <gpg-key>:
    Userid : "MemSQL Release Engineering <>"
    Fingerprint: <fingerprint>
    From :
    Key import failed (code 2). Failing package is: singlestore-client-1.0.7-1.x86_64
    GPG Keys are configured as:
    Public key for singlestoredb-toolbox-1.13.13-9fa4ef2d34.x86_64.rpm is not installed.
    Failing package is: singlestoredb-toolbox-1.13.13-1.x86_64
    GPG Keys are configured as:
    The downloaded packages were saved in cache until the next successful transaction.
    You can remove cached packages by executing 'yum clean packages'.
    Error: GPG check FAILED
    • View the current crypto policies.

      update-crypto-policies --show
    • If SHA1 is not present, update the crypto policies to work with SingleStore Tools.

      sudo update-crypto-policies --set DEFAULT:SHA1

      Refer to Using system-wide cryptographic policies for more information.

Deploy SingleStore



Before deploying a SingleStore cluster in a production environment, please review and follow the host configuration recommendations. Failing to follow these recommendations will result in sub-optimal cluster performance.

In addition, SingleStore recommends that each Master Aggregator and child aggregator reside on its own host when deploying SingleStore in a production environment.

Notes on Users and Groups

The user that deploys SingleStore via SingleStore Toolbox must be able to SSH to each host in the cluster. When singlestoredb-server is installed via an RPM or Debian package when deploying SingleStore, a memsql user and group are also created on each host in the cluster.

This memsql user does not have a shell, and attempting to log in or SSH as this user will fail. The user that deploys SingleStore is added to the memsql group. This group allows most Toolbox commands to run without sudo privileges, and members of this group can perform many Toolbox operations without the need to escalate to sudo. Users who desire to run SingleStore Toolbox commands must be added to the memsql group on each host in the cluster. They must also be able to SSH to each host.

Manually creating a memsql user and group is only recommended in a sudo-less environment when performing a tarball-based deployment of SingleStore. In order to run SingleStore Toolbox commands against a cluster, this manually-created memsql user must be configured so that it can SSH to each host in the cluster.

Minimal Deployment

SingleStore has been designed to be deployed with at least two nodes:

  • A Master Aggregator node that runs SQL queries and aggregates the results, and

  • A single leaf node, which is responsible for storing and processing data

These two nodes can be deployed on a single host (via the cluster-in-box option), or on two hosts, with one SingleStore node on each host.

While additional aggregators and nodes can be added and removed as required, a minimal deployment of SingleStore always consists of at least these two nodes.

Cluster-in-a-Box CLI Online Deployment


If you are deploying SingleStore on a host or virtual machine (VM), and want to connect to the cluster from a separate host or the VM's host, set the bind address from 127.0.01 to

To do so, include either:

Option 1: Command Line

You can deploy your SingleStore cluster on a single host using the sdb-deploy cluster-in-a-box command. This command will create two nodes: A Master Aggregator node that runs SQL queries and aggregates the results, and a single leaf node, which is responsible for storing and processing data. These two nodes form the most basic SingleStore cluster.

  • The default port for the Master Aggregator can be changed by adding the --master-port option and specifying the desired port.

  • The default port for the leaf node can be changed by adding the --leaf-port option and specifying the desired port.

sdb-deploy cluster-in-a-box --license <license> --version 7.3 --password <secure-password>

Note: You can retrieve the license from the Cloud Portal.


If your host does not have the which command available, you will need to specify the correct package through the --force-package-format {rpm | deb} flag when running the cluster-in-a-box command.

Option 2: Cluster File

This example is equivalent to sdb-deploy cluster-in-a-box, where a single-host cluster is created with two nodes: a Master Aggregator and a single leaf node.

Set package_type to either rpm for Red Hat distributions or deb for Debian distributions to download and deploy the appropriate singlestoredb-server.

license: <>
memsql_server_version: 7.3
package_type: <rpm|deb>
- hostname:
localhost: true
- register: false
role: Master
password: <secure-password>
port: 3306
- register: false
role: Leaf
password: <secure-password>
port: 3307

Using this cluster configuration file, sdb-deploy setup-cluster:

  1. Registers a single, local host to the cluster.

  2. Installs the latest 7.3 version of singlestoredb-server on this host.

  3. Creates a Master Aggregator node on port 3306 and sets the SingleStore password to the one specified in the cluster file.

  4. Creates a leaf node on port 3307 and sets the SingleStore password to the one specified in the cluster file.

  5. Run the following with the path to the cluster file as input.

    sdb-deploy setup-cluster --cluster-file </path/to/cluster-file>

Additional Deployment Options


If this deployment method is not ideal for your target environment, you can choose one that fits your requirements from the Deployment Options.

Connect to Your Cluster

The singlestore-client package contains is a lightweight client application that allows you to run SQL queries against your database from a terminal window.

After you have installed singlestore-client, use the singlestore application as you would use the mysql client to access your database.

For more connection options, help is available through singlestore --help.

singlestore -h <Master-or-Child-Aggregator-host-IP-address> -P <port> -u <user> -p<secure-password>
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 12
Server version: 5.5.58 MemSQL source distribution (compatible; MySQL Enterprise & MySQL Commercial)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.


Refer to Connect to Your Cluster for additional options for connecting to SingleStore.

Next Steps After Deployment

Now that you have installed SingleStore, check out the following resources to learn more about SingleStore:

Last modified: September 18, 2023

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