# SingleStore Server Config Files The following directory structures reflect the default locations of a number of SingleStore processes and configuration files. For deployments using RPM and Debian packages, SingleStore follows the Linux Standard Base (LSB) layout. ``` /opt/singlestoredb-server--/ ├── memsqld The memsqld process └── memsqlctl A tool to control and manage the nodes on a host /etc/memsql/ └── memsqlctl.hcl The memsqlctl configuration file /etc/systemd/system └── memsql.service The memsql service file ``` The following table lists each of these files and provides the location of each file, additional information about each file, and each file’s format. | **File** | **Location & Description** | **Format** | | -------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------- | | `memsqld` | `/opt/singlestoredb-server--/memsqld` | Binary | | | The`memsqld`process.The`memsqld`process runs under the`memsql:memsql`user and group on each host, which owns all of theSingleStoredata and configuration files. This user and group are automatically created whenSingleStoreis deployed using a Debian or an RPM package, but must be created manually when deployed in a`sudo`-less environment using a tarball.The`memsqlctl`command can be used to start or stop`memsqld`and must be run by either the`memsql`user or the Linux`root`user (where, as`root`, this command is run as the`memsql`user).The user and group that can run`memsqld`can be changed in the node configuration file,`memsql.cnf`.**Note**: The location of the`memsqld`binary is dictated by the`singlestoredb-server`package during deployment. Specifying the location of the`memsqld`binary is only possible with[tarball-based deployments](https://docs.singlestore.com/db/v9.1/deploy/linux.md). | | | `memsqlctl` | `/usr/bin/memsqlctl``/opt/singlestoredb-server--/memsqlctl` | Binary | | | A low-level tool used to control and manage the nodes on a host where`memsqlctl`is installed.Wraps several SQL commands that perform management tasks, and can be automated by popular configuration management tools.Controls the startup process of`memsqld`, which reads the node configuration file,[memsql.cnf](https://docs.singlestore.com/db/v9.1/reference/configuration-reference/cluster-config-files/singlestore-node-config-files.md), when starting up. As`memsqlctl`controls the`memsqld`process and node configuration,`memsqlctl`must be run as the user who runs`memsqld`, or a Linux user with`root`privileges.The`memsqlctl`tool is included in the`singlestoredb-server`/`memsql-server`package/tarball file along with theSingleStoredatabase engine.Similar, but not strictly equivalent, to[sdb-admin](https://docs.singlestore.com/db/v9.1/reference/singlestore-tools-reference/sdb-admin-commands.md). | | | `memsqlctl.hcl` | `/etc/memsql/memsqlctl.hcl` | [HCL](https://github.com/hashicorp/hcl#syntax) | | | The`memsqlctl`configuration file.This file can be used to override the default engine variable settings for the entireclusterand contains the following entries:
  • defaultInstallDir: The default installation directory for nodes that are created by memsqlctl. Must be owned by the user specified by the user entry in this file. Default locations:
    • /var/lib/memsql: RPM and Debian package-based deployments
    • tarInstallDir/nodes: Tarball-based deployments
  • nodeMetadataFile: The path to the memsqlctl state file, nodes.hcl, where memsqlctl stores information about the nodes that reside on a host. Must be owned by the user specified by the user entry in this file.
  • sslCaFile: The path to the certificate authority (CA) certificate file, in PEM format. The path can be absolute or relative to the location of the memsqlctl.hcl file. Used by memsqlctl to authenticate the SingleStore server certificate on each node.
  • user: The user (username) that runs memsqld and that owns everything SingleStore-related on a host, including:
    • The defaultInstallDir and its contents
    • The nodeMetadataFile
    • The memsql.cnf files
    • Data directories
    • Log files
    To change this value:
    • Update the user entry in this file
    • Update the permissions on all SingleStore-related files and directories
    • Restart all nodes on the host
Example`memsqlctl.hcl`file, with default values.`version = 1 nodeMetadataFile = "/var/lib/memsql/nodes.hcl" defaultInstallDir = "/var/lib/memsql" user = "memsql"`To prevent unintentionally running nodes as`root`,`memsqlctl`will display an error unless`user = "root"`is explicitly set in this file.The default installation process creates a`memsql:memsql`service user and group which runsSingleStore.All states, and all nodes created by`memsqlctl`on a host, are owned by the`memsql:memsql`user and group. | | | **`memsql.service`** | `/etc/systemd/system/memsql.service` | Text | | | The`memsql`service file.When the`memsql`service is enabled, all nodes on a host are restarted after the host is rebooted.WhenSingleStoreis deployed via package, the`memsql.service`file and the`memsql`service are created and enabled automatically.WhenSingleStoreis deployed via tarball, the`memsql.service`file and the`memsql`service must be created and enabled manually. The instructions for creating the`memsql.service`file and enabling the`memsql`service are included in each tarball-based[deployment guide](https://docs.singlestore.com/db/v9.1/deploy/linux.md).The following is an example`memsql.service`file.`[Unit] Description=SingleStore After=network.target [Service] Type=oneshot RemainAfterExit=yes ExecStart=/opt/singlestore/singlestoredb-server/memsqlctl start-node --yes --all ExecStop=/opt/singlestore/singlestoredb-server/memsqlctl stop-node --yes --all Slice=system-memsql.slice TasksMax = 128000 LimitNICE=-10 LimitNOFILE=1024000 LimitNPROC=128000 [Install] WantedBy=multi-user.target` | | *** Modified at: August 21, 2024 Source: [/db/v9.1/reference/configuration-reference/cluster-config-files/singlestore-server-config-files/](https://docs.singlestore.com/db/v9.1/reference/configuration-reference/cluster-config-files/singlestore-server-config-files/) (An index of the documentation is available at /llms.txt)