See the Security Management Commands Overview for reference material related to security commands used throughout the security guides in this section.
This topic does not apply to SingleStore Managed Service.
If you are managing your cluster with MemSQL Ops, go here.
SingleStore DB supports features for user authentication, password policies, fine-grained access controls, and certificate-based network encryption between clients and the database cluster, as well as between individual nodes in the cluster.
By default, you can log into SingleStore DB with the
root user, but must specify a password to connect to the database, or explicitly define an empty password during deployment to connect without specifying a password. This page describes configuration changes and best practices required to secure SingleStore DB.
Configuring SingleStore DB user accounts
By default, user accounts are configured independently on each aggregator node. Whenever you add a new aggregator node, you will also need to configure user accounts on it. Users do not normally connect to leaves, so it is generally not necessary to configure user accounts on leaf nodes. Only the
root user is required on leaf nodes.
Also, you can automatically synchronize non-root user accounts across your cluster to avoid manually managing these accounts on each aggregator node. See Synchronize Permissions for more details on how to enable this functionality.
Securing the initial SingleStore DB user accounts
When SingleStore DB is installed, the
root user is created on each SingleStore node. You are required to set a password when running sdb-admin create-node, but this can be set to a blank password for testing purposes. As a best practice, you should set a secure password for the
Once your cluster is deployed, you can also change the password for the
root user with the sdb-admin change-root-password command. This command configures the
root password for a single SingleStore node. To configure the password on all nodes in a cluster, run:
sdb-admin change-root-password --all --yes --password <secure_password>
root password is an online operation for both aggregators and leaves and you do not have to perform any additional operations; however, you must ensure your nodes are running before calling the
root password via a command-line argument is often not secure and SingleStore recommends safer, alternative methods to configure passwords.
While it is convenient to set the
root password using a command-line argument, it is often recommended against this practice for security reasons. The command-line argument accepts passwords entered as plain text, which makes them vulnerable to being discovered in the list of processes running on the system during application runtime. The plain text passwords could also be saved and accessed in the history file if your command-line interpreter maintains a history. For example, in Bash, the command history including password inputs is logged at ~/.bash_history. In addition, the
root password supplied as a command-line argument is displayed on-screen and is visible to anyone who is reading the user’s screen.
Some of the more secure, alternative methods to set SingleStore DB
root password are as follows.
- Set the
rootpassword using the
MEMSQL_PASSWORDenvironment variable. This option is best suited for automated applications.
- As of SingleStore DB Toolbox 1.6.4, Toolbox commands can solicit the
rootpassword interactively from users. The passwords entered in an interactive prompt are not displayed on-screen and are effectively secured from anyone reading the user’s screen. The interactive prompt is invoked if neither the
--passwordflag nor the
MEMSQL_PASSWORDenvironment variable has been used to set the
Deleting unnecessary default users
In MemSQL 6.0 and later, the only default user created on each SingleStore node during installation is the
'root'@'%' user, which should be configured as described in the previous section.
In MemSQL 5.8 and earlier, several default users are created on each SingleStore node during installation. We recommend deleting all of these default users except for the
To delete these users, use the
DROP USER command. On each SingleStore node (including both aggregators and leaves), log in as the
root user or another user with sufficient permissions, and run:
DROP USER ''@'localhost'; DROP USER ''@'127.0.0.1'; DROP USER 'root'@'localhost'; DROP USER 'dashboard'@'%'; DROP USER 'dashboard'@'localhost';
These additional default users are created in MemSQL installations of 5.8 and earlier, but not 6.0 and later. They are not changed during upgrade, so a cluster installed on 5.8 or earlier and upgraded to 6.0 or later will still have these user accounts, unless you have deleted them.
Note that since user accounts are configured independently on each node, whenever you add a new SingleStore node, you should also delete any unnecessary default users on it.
''@'127.0.0.1' are “anonymous” user accounts, which allow any user to log in from the localhost (with a limited set of permissions). The blank user string matches any username - for example, attempting to log in as user
alice from localhost will match the
''@'localhost' user, unless a user account
'alice'@'localhost' exists, in which case that takes precedence. Note that even if a user account
'alice'@'%' exists, the anonymous user account takes precedence over that. More specific hostnames take precedence first, and a specific username takes precedence over a blank “anonymous” username for the same hostname specificity. For example, a login as user ‘alice’ from localhost matches
'alice'@'%' in that order of precedence. This can cause unexpected behavior: if you have the anonymous users and an
'alice'@'%' user, but not an
'alice'@'localhost' user, when you attempt to log in as the user ‘alice’ from localhost, you will be logged in as
''@'localhost', whereas when you attempt to log in as the user ‘alice’ from any other host, you will be logged in as the
'alice'@'%' user. We recommend deleting the anonymous user accounts.
For this reason, the
'root'@'localhost' account is necessary only when the anonymous user accounts for localhost are present. Logging in as the
root user from localhost matches
'root'@'%' in that order of precedence. Therefore, when the anonymous user accounts are not present, the
'root'@'localhost' account can be removed, leaving only the
'root'@'%' account. We recommend deleting the
'root'@'localhost' account in addition to the anonymous user accounts to avoid the possibility of misconfiguring the
'root'@'%' accounts differently (for example, misconfiguring them with different passwords).
'dashboard'@'localhost' accounts were used by MemSQL Ops versions prior to 4.0. They are no longer used, so we recommend deleting them.
Adding a User
To add a user, use the GRANT command. If you have
sync_permissions enabled on your cluster, log into the master aggregator as the
root user or another user with sufficient permissions, and run:
GRANT <grant_options> TO '<user>'@'<host>' IDENTIFIED BY '<password>'
GRANT SELECT, INSERT ON db.* TO 'username'@'%' IDENTIFIED BY 'password'
See the GRANT documentation for more details.
If you do not have
sync_permissions enabled, then you must perform the above operations on each aggregator in your cluster.
You can also use Kerberos, SAML, or PAM instead of password-based authentication.
Changing a Password for a User
To change a password for a user, you have the following options:
GRANTas shown in the previous section. You must have
SUPERprivileges to change another user’s password.
SET PASSWORDto create a password hash and assign it to the user. Users can also change their own password with this command.
SET PASSWORD FOR 'username'@'host' = PASSWORD('password');
Removing a User
To remove a user, use the DROP USER command. Similar to other user management operations, if you have
sync_permissions enabled, log into the master aggregator as the
root user or another user with sufficient permissions, and run:
DROP USER '<user>'@'<host>'
sync_permissions is not enabled, then you must perform this operation on each aggregator in the cluster.
You can view grants and permissions by querying
You can also view grants for a user by running SHOW GRANTS:
SHOW GRANTS FOR user@domain;
Setting a Failed Login Attempt Lockout Policy
You can specify the number of times a user can enter an incorrect password before they are locked out of the system. When a user reaches this limit, their account is locked for the specified number of seconds.
This feature can be enabled per user or per role, in which case every user belonging to that role will be subject to failed login attempt lockout.
Enabling the Lockout Policy
To enable the lockout policy:
PASSWORD_LOCK_TIME for the user or role.
FAILED_LOGIN_ATTEMPTS is the number of failed attempts before the account is locked, for example:
PASSWORD_LOCK_TIME is the number of seconds a locked out account must wait before reattempting to log in.
You must set both
PASSWORD_LOCK_TIME to enable the feature.
Enable the lockout feature at 4 failed attempts, with a lockout time of 4 hours (14400 seconds) when creating a user:
CREATE USER user1 WITH FAILED_LOGIN_ATTEMPTS = 4 PASSWORD_LOCK_TIME = 14400;
Enabling the feature for a role:
CREATE ROLE general WITH FAILED_LOGIN_ATTEMPTS = 4 PASSWORD_LOCK_TIME = 14400;
If a user is associated with more than one role with different password lock times, the larger
PASSWORD_LOCK_TIME value is applied.
If a user and a role the user is tied to have conflicting
FAILED_LOGIN_ATTEMPTS settings, the lower value is applied.
Updating Lockout Settings
PASSWORD_LOCK_TIME value is updated for a role or user, the new setting applies to currently locked accounts. For example, if a locked out user’s lockout time setting is 1 day, and
PASSWORD_LOCK_TIME is then set to 4 hours, the new limit is enforced and the account will be unlocked 4 hours after it was locked. If a user’s lockout time setting is 4 hours, and the setting is increased to 1 day, the user will remain locked out for 1 day.
FAILED_LOGIN_ATTEMPTS setting for a locked out user is updated to be higher than the current setting, the user is unlocked. If the new setting is lower than the current number of failed login attempts, and also higher than the user’s current number of failed login attempts, the new setting is ignored until the user successfully logs in. The user is still subject to the original
Unlocking a Locked Account
To unlock a locked account:
ALTER USER command and specify
ALTER USER user ACCOUNT UNLOCK;
If sync permissions is not enabled,
ACCOUNT UNLOCK should be issued on the aggregator where the user is to be unlocked.
sync_permissions is enabled,
ACCOUNT UNLOCK should be issued on the Master Aggregator since all user modifications will have to come from the Master. This will unlock the account across the cluster.
Configuring Host-Based Security
You can use a firewall to restrict which hosts can access SingleStore DB. For example, if you’re running a cluster on Amazon EC2, you can configure security groups to restrict network access by specifying allowed IP addresses or security groups.
You can also set the
bind-address variable to restrict the range of IP addresses which are allowed to connect to SingleStore DB. For example, if you set it to
127.0.0.1, you will only be able to connect to SingleStore DB locally. See
bind_address in the list of engine variables.
secure_file_priv global variable controls where users with the FILE READ and FILE WRITE privilege can read or save files. It should be set on all nodes to a directory that is not used by SingleStore DB or other software. If not set, a user with the FILE READ or FILE WRITE privilege can tamper with the system by reading or creating files in sensitive locations. For information on how to set engine variables, see the engine variables overview.
Encryption at Rest
SingleStore DB is compatible with at-rest disk-based encryption via LUKS (Linux Unified Key Setup). SingleStore DB is also compatible with other encryption solutions that may have different security characteristics. Please see our partner integrations documentation or contact us if you have questions about using SingleStore DB with other encryption technologies.
To use SingleStore DB with LUKS, configure your block device to be encrypted with LUKS, and then simply install SingleStore DB on the encrypted volume.
For more information about how to implement LUKS with different versions of Linux, see the links in the section below. Note that ‘ecryptfs’ should never be used - only volume or block level encryption.
Example Setup Process
- Prepare block device
- Encrypt block device with LUKS
- Create filesystem (i.e.,
- Mount filesystem (i.e.,
mount /dev/mapper/myencryptedvolume /data)
- Install SingleStore DB normally to encrypted location using the SingleStore management tools or MemSQL Ops
How to Use LUKS With Different Versions of Linux
Red Hat Enterprise Linux: For an overview on using LUKS with Red Hat, go here.
- Red Hat Enterprise Linux version 5 (Linux kernel 2.6.18-8)
- Red Hat Enterprise Linux version 6 (Linux kernel 2.6.32-71)
- Red Hat Enterprise Linux version 7 (Linux kernel 3.10.0-123)
SUSE Linux Enterprise Server:
- SUSE version 10 (Linux kernel 22.214.171.124-0.8)
- SUSE version 11 (Linux kernel 126.96.36.199-5.1)
- SUSE version 12 (Linux kernel 3.12.28-4.6)
Ubuntu: For information about implementing LUKS on Ubuntu, go here.
openSUSE: For information about implementing LUKS on openSUSE, go here.