Configuration reference

This topic describes all configuration parameters provided by Tarantool.

Most of the configuration options described in this reference can be applied to a specific instance, replica set, group, or to all instances globally. To do so, you need to define the required option at the specified level.

audit_log

Enterprise Edition

Configuring audit_log parameters is available in the Enterprise Edition only.

The audit_log section defines configuration parameters related to audit logging.

Note

audit_log can be defined in any scope.

audit_log.extract_key
audit_log.file
audit_log.filter
audit_log.format
audit_log.nonblock
audit_log.pipe
audit_log.spaces
audit_log.to
audit_log.syslog.*

audit_log.extract_key¶

Since: 3.0.0.

If set to true, the audit subsystem extracts and prints only the primary key instead of full tuples in DML events (space_insert, space_replace, space_delete). Otherwise, full tuples are logged. The option may be useful in case tuples are big.

Type: boolean
Default: false
Environment variable: TT_AUDIT_LOG_EXTRACT_KEY

audit_log.file¶: Specify a file for the audit log destination. You can set the file type using the audit_log.to option. If you write logs to a file, Tarantool reopens the audit log at SIGHUP.

Type: string

Default: ‘var/log/{{ instance_name }}/audit.log’

Environment variable: TT_AUDIT_LOG_FILE

audit_log.filter¶

Enable logging for a specified subset of audit events. This option accepts the following values:

Event names (for example, password_change). For details, see Audit log events.
Event groups (for example, audit). For details, see Event groups.

The option contains either one value from Possible values section (see below) or a combination of them.

To enable custom audit log events, specify the custom value in this option.

Example

filter: [ user_create,data_operations,ddl,custom ]

Type: array
Possible values: ‘all’, ‘audit’, ‘auth’, ‘priv’, ‘ddl’, ‘dml’, ‘data_operations’, ‘compatibility’,
‘audit_enable’, ‘auth_ok’, ‘auth_fail’, ‘disconnect’, ‘user_create’, ‘user_drop’, ‘role_create’, ‘role_drop’,
‘user_disable’, ‘user_enable’, ‘user_grant_rights’, ‘role_grant_rights’, ‘role_revoke_rights’, ‘password_change’,
‘access_denied’, ‘eval’, ‘call’, ‘space_select’, ‘space_create’, ‘space_alter’, ‘space_drop’, ‘space_insert’,
‘space_replace’, ‘space_delete’, ‘custom’
Default: ‘nil’
Environment variable: TT_AUDIT_LOG_FILTER

audit_log.format¶

Specify a format that is used for the audit log.

Example

If you set the option to plain,

audit_log:
    to: file
    format: plain

the output in the file might look as follows:

2024-01-17T00:12:27.155+0300
4b5a2624-28e5-4b08-83c7-035a0c5a1db9
INFO remote:unix/:(socket)
session_type:console
module:tarantool
user:admin
type:space_create
tag:
description:Create space Bands

Type: string
Possible values: ‘json’, ‘csv’, ‘plain’
Default: ‘json’
Environment variable: TT_AUDIT_LOG_FORMAT

audit_log.nonblock¶: Specify the logging behavior if the system is not ready to write. If set to true, Tarantool does not block during logging if the system is non-writable and writes a message instead. Using this value may improve logging performance at the cost of losing some log messages.

Note

The option only has an effect if the audit_log.to is set to syslog or pipe.

Type: boolean

Default: false

Environment variable: TT_AUDIT_LOG_NONBLOCK

audit_log.pipe¶

Specify a pipe for the audit log destination. You can set the pipe type using the audit_log.to option. If log is a program, its pid is stored in the audit.pid field. You need to send it a signal to rotate logs.

Example

audit_log:
  to: pipe
  pipe: '| cronolog audit_tarantool.log'

This starts the cronolog program when the server starts and sends all audit_log messages to cronolog standard input (stdin). If the audit_log string starts with ‘|’, the string is interpreted as a Unix pipeline.

Type: string
Default: box.NULL
Environment variable: TT_AUDIT_LOG_PIPE

audit_log.spaces¶

Since: 3.0.0.

The array of space names for which data operation events (space_select, space_insert, space_replace, space_delete) should be logged. The array accepts string values. If set to box.NULL, the data operation events are logged for all spaces.

Example

In the example, only the events of bands and singers spaces are logged:

audit_log:
  spaces: [bands, singers]

Type: array
Default: box.NULL
Environment variable: TT_AUDIT_LOG_SPACES

audit_log.to¶

Enable audit logging and define the log location. This option accepts the following values:

devnull: disable audit logging.
file: write audit logs to a file (see audit_log.file).
pipe: start a program and write audit logs to it (see audit_log.pipe).
syslog: write audit logs to a system logger (see audit_log.syslog.*).

By default, audit logging is disabled.

Example

The basic audit log configuration might look as follows:

audit_log:
  to: file
  file: 'audit_tarantool.log'
  filter: [ user_create,data_operations,ddl,custom ]
  format: json
  spaces: [ bands ]
  extract_key: true

Type: string
Possible values: ‘devnull’, ‘file’, ‘pipe’, ‘syslog’
Default: ‘devnull’
Environment variable: TT_AUDIT_LOG_TO

audit_log.syslog.*

audit_log.syslog.facility¶

Specify a system logger keyword that tells syslogd where to send the message. You can enable logging to a system logger using the audit_log.to option.

config

The config section defines various parameters related to centralized configuration.

Note

config can be defined in the global scope only.

config.reload
config.context.*
config.etcd.*
config.storage.*

config.reload¶

Since: 3.0.0.

Specify how the configuration is reloaded. This option accepts the following values:

auto: configuration is reloaded automatically when it is changed.
manual: configuration should be reloaded manually. In this case, you can reload the configuration in the application code using config:reload().

config.context.*

This section describes options related to loading configuration settings from external storage such as external files or environment variables.

config.context
- config.context.<name>

config.context¶

Since: 3.0.0.

Specify how to load settings from external storage. For example, this option can be used to load passwords from safe storage. You can find examples in the Loading secrets from safe storage section.

Type: map
Default: nil
Environment variable: TT_CONFIG_CONTEXT

config.context.<name>¶: The name of an entity that identifies a configuration value to load.

config.context.<name>.env¶

The name of an environment variable to load a configuration value from. To load a configuration value from an environment variable, set config.context.<name>.from to env.

Example:

In this example, passwords are loaded from the DBADMIN_PASSWORD and SAMPLEUSER_PASSWORD environment variables:

config:
  context:
    dbadmin_password:
      from: env
      env: DBADMIN_PASSWORD
    sampleuser_password:
      from: env
      env: SAMPLEUSER_PASSWORD

config.context.<name>.from¶

The type of storage to load a configuration value from. There are the following storage types:

file: load a configuration value from a file. In this case, you need to specify the path to the file using config.context.<name>.file.
env: load a configuration value from an environment variable. In this case, specify the environment variable name using config.context.<name>.env.

config.context.<name>.file¶

The path to a file to load a configuration value from. To load a configuration value from a file, set config.context.<name>.from to file.

Example:

In this example, passwords are loaded from the dbadmin_password.txt and sampleuser_password.txt files:

config:
  context:
    dbadmin_password:
      from: file
      file: secrets/dbadmin_password.txt
      rstrip: true
    sampleuser_password:
      from: file
      file: secrets/sampleuser_password.txt
      rstrip: true

config.context.<name>.rstrip¶: (Optional) Whether to strip whitespace characters and newlines from the end of data.

config.etcd.*

Enterprise Edition

Centralized configuration storages are supported by the Enterprise Edition only.

This section describes options related to providing connection settings to a centralized etcd-based storage.

config.etcd.endpoints
config.etcd.prefix
config.etcd.username
config.etcd.password
config.etcd.ssl.ca_file
config.etcd.ssl.ca_path
config.etcd.ssl.ssl_key
config.etcd.ssl.verify_host
config.etcd.ssl.verify_peer
config.etcd.http.request.timeout
config.etcd.http.request.unix_socket

config.etcd.endpoints¶

Since: 3.0.0.

The list of endpoints used to access an etcd server.

Type: array
Default: nil
Environment variable: TT_CONFIG_ETCD_ENDPOINTS

config.etcd.prefix¶

Since: 3.0.0.

A key prefix used to search a configuration on an etcd server. Tarantool searches keys by the following path: <prefix>/config/*. Note that <prefix> should start with a slash (/).

Type: string
Default: nil
Environment variable: TT_CONFIG_ETCD_PREFIX

config.etcd.username¶

Since: 3.0.0.

A username used for authentication.

Type: string
Default: nil
Environment variable: TT_CONFIG_ETCD_USERNAME

config.etcd.password¶

Since: 3.0.0.

A password used for authentication.

Type: string
Default: nil
Environment variable: TT_CONFIG_ETCD_PASSWORD

config.etcd.ssl.ca_file¶

Since: 3.0.0.

A path to a trusted certificate authorities (CA) file.

Type: string
Default: nil
Environment variable: TT_CONFIG_ETCD_SSL_CA_FILE

config.etcd.ssl.ca_path¶

Since: 3.0.0.

A path to a directory holding certificates to verify the peer with.

Type: string
Default: nil
Environment variable: TT_CONFIG_ETCD_SSL_CA_PATH

config.etcd.ssl.ssl_key¶

Since: 3.0.0.

A path to a private SSL key file.

Type: string
Default: nil
Environment variable: TT_CONFIG_ETCD_SSL_SSL_KEY

config.etcd.ssl.verify_host¶

Since: 3.0.0.

Enable verification of the certificate’s name (CN) against the specified host.

Type: boolean
Default: nil
Environment variable: TT_CONFIG_ETCD_SSL_VERIFY_HOST

config.etcd.ssl.verify_peer¶

Since: 3.0.0.

Enable verification of the peer’s SSL certificate.

Type: boolean
Default: nil
Environment variable: TT_CONFIG_ETCD_SSL_VERIFY_PEER

config.etcd.http.request.timeout¶

Since: 3.0.0.

A time period required to process an HTTP request to an etcd server: from sending a request to receiving a response.

Type: number
Default: nil
Environment variable: TT_CONFIG_ETCD_HTTP_REQUEST_TIMEOUT

config.etcd.http.request.unix_socket¶

Since: 3.0.0.

A Unix domain socket used to connect to an etcd server.

Type: string
Default: nil
Environment variable: TT_CONFIG_ETCD_HTTP_REQUEST_UNIX_SOCKET

config.storage.*

Enterprise Edition

Centralized configuration storages are supported by the Enterprise Edition only.

This section describes options related to providing connection settings to a centralized Tarantool-based storage.

config.storage.endpoints
config.storage.prefix
config.storage.reconnect_after
config.storage.timeout

config.storage.endpoints¶

Since: 3.0.0.

An array of endpoints used to access a configuration storage. Each endpoint can include the following fields:

uri: a URI of the configuration storage’s instance.
login: a username used to connect to the instance.
password: a password used for authentication.
params: SSL parameters required for encrypted connections (<uri>.params.*).

Type: array
Default: nil
Environment variable: TT_CONFIG_STORAGE_ENDPOINTS

config.storage.prefix¶

Since: 3.0.0.

A key prefix used to search a configuration in a centralized configuration storage. Tarantool searches keys by the following path: <prefix>/config/*. Note that <prefix> should start with a slash (/).

Type: string
Default: nil
Environment variable: TT_CONFIG_STORAGE_PREFIX

config.storage.reconnect_after¶

Since: 3.0.0.

A number of seconds to wait before reconnecting to a configuration storage.

Type: number
Default: 3
Environment variable: TT_CONFIG_STORAGE_RECONNECT_AFTER

config.storage.timeout¶

Since: 3.0.0.

The interval (in seconds) to perform the status check of a configuration storage.

Type: number
Default: 3
Environment variable: TT_CONFIG_STORAGE_TIMEOUT

credentials

The credentials section allows you to create users and grant them the specified privileges. Learn more in Credentials.

Note

credentials can be defined in any scope.

credentials.roles.*
credentials.users.*
<user_or_role_name>.privileges.*

credentials.roles.*

credentials.roles
- credentials.roles.<role_name>.roles
- credentials.roles.<role_name>.privileges

credentials.roles¶

An array of roles that can be granted to users or other roles.

Example:

In the example below, the writers_space_reader role gets privileges to select data in the writers space:

roles:
  writers_space_reader:
    privileges:
    - permissions: [ read ]
      spaces: [ writers ]

See also: Managing users and roles.

Type: map
Default: nil
Environment variable: TT_CREDENTIALS_ROLES

credentials.roles.<role_name>.roles¶: An array of roles granted to this role.

credentials.roles.<role_name>.privileges¶

An array of privileges granted to this role.

See <user_or_role_name>.privileges.*.

credentials.users.*

credentials.users

credentials.users¶

An array of users.

Example:

In this example, sampleuser gets the following privileges:

Privileges granted to the writers_space_reader role.
Privileges to select and modify data in the books space.

sampleuser:
  password: '123456'
  roles: [ writers_space_reader ]
  privileges:
  - permissions: [ read, write ]
    spaces: [ books ]

See also: Managing users and roles.

Type: map
Default: nil
Environment variable: TT_CREDENTIALS_USERS

credentials.users.<username>.password¶

A user’s password.

Example:

In the example below, a password for the dbadmin user is set:

credentials:
  users:
    dbadmin:
      password: 'T0p_Secret_P@$$w0rd'

credentials.users.<username>.roles¶: An array of roles granted to this user.

credentials.users.<username>.privileges¶

An array of privileges granted to this user.

See <user_or_role_name>.privileges.*.

<user_or_role_name>.privileges.*

<user_or_role_name>.privileges

<user_or_role_name>.privileges¶

Privileges that can be granted to a user or role using the following options:

credentials.users.<username>.privileges
credentials.roles.<role_name>.privileges

<user_or_role_name>.privileges.permissions¶

Permissions assigned to this user or a user with this role.

Example:

In this example, sampleuser gets privileges to select and modify data in the books space:

sampleuser:
  password: '123456'
  roles: [ writers_space_reader ]
  privileges:
  - permissions: [ read, write ]
    spaces: [ books ]

See also: Managing users and roles.

<user_or_role_name>.privileges.spaces¶

Spaces to which this user or a user with this role gets the specified permissions.

Example:

In this example, sampleuser gets privileges to select and modify data in the books space:

sampleuser:
  password: '123456'
  roles: [ writers_space_reader ]
  privileges:
  - permissions: [ read, write ]
    spaces: [ books ]

See also: Managing users and roles.

<user_or_role_name>.privileges.functions¶: Functions to which this user or a user with this role gets the specified permissions.

<user_or_role_name>.privileges.sequences¶: Sequences to which this user or a user with this role gets the specified permissions.

<user_or_role_name>.privileges.lua_eval¶: Whether this user or a user with this role can execute arbitrary Lua code.

<user_or_role_name>.privileges.lua_call¶: Whether this user or a user with this role can call any global user-defined Lua function.

<user_or_role_name>.privileges.sql¶: Whether this user or a user with this role can execute an arbitrary SQL expression.

database

The database section defines database-specific configuration parameters, such as an instance’s read-write mode or transaction isolation level.

Note

database can be defined in any scope.

database.hot_standby
database.instance_uuid
database.mode
database.replicaset_uuid
database.txn_isolation
database.txn_timeout
database.use_mvcc_engine

database.hot_standby¶: Type: boolean

Default: false

Environment variable: TT_DATABASE_HOT_STANDBY

database.instance_uuid¶

An instance UUID.

By default, instance UUIDs are generated automatically. database.instance_uuid can be used to specify an instance identifier manually.

UUIDs should follow these rules:

The values must be true unique identifiers, not shared by other instances or replica sets within the common infrastructure.
The values must be used consistently, not changed after the initial setup. The initial values are stored in snapshot files and are checked whenever the system is restarted.
The values must comply with RFC 4122. The nil UUID is not allowed.

flightrec

Enterprise Edition

Configuring flightrec parameters is available in the Enterprise Edition only.

The flightrec section describes options related to the flight recorder configuration.

Note

flightrec can be defined in any scope.

flightrec.enabled
flightrec.logs_size
flightrec.logs_max_msg_size
flightrec.logs_log_level
flightrec.metrics_period
flightrec.metrics_interval
flightrec.requests_size
flightrec.requests_max_req_size
flightrec.requests_max_res_size

flightrec.enabled¶: Enable the flight recorder.

Type: boolean

Default: false

Environment variable: TT_FLIGHTREC_ENABLED

flightrec.logs_size¶: Specify the size (in bytes) of the log storage. You can set this option to 0 to disable the log storage.

Type: integer

Default: 10485760

Environment variable: TT_FLIGHTREC_LOGS_SIZE

flightrec.logs_max_msg_size¶: Specify the maximum size (in bytes) of the log message. The log message is truncated if its size exceeds this limit.

Type: integer

Default: 4096

Maximum: 16384

Environment variable: TT_FLIGHTREC_LOGS_MAX_MSG_SIZE

flightrec.logs_log_level¶: Specify the level of detail the log has. The default value is 6 (VERBOSE). You can learn more about log levels from the log_level option description. Note that the flightrec.logs_log_level value might differ from log_level.

Type: integer

Default: 6

Environment variable: TT_FLIGHTREC_LOGS_LOG_LEVEL

flightrec.metrics_period¶: Specify the time period (in seconds) that defines how long metrics are stored from the moment of dump. So, this value defines how much historical metrics data is collected up to the moment of crash. The frequency of metric dumps is defined by flightrec.metrics_interval.

Type: integer

Default: 180

Environment variable: TT_FLIGHTREC_METRICS_PERIOD

flightrec.metrics_interval¶

Specify the time interval (in seconds) that defines the frequency of dumping metrics. This value shouldn’t exceed flightrec.metrics_period.

Type: number
Default: 1.0
Minimum: 0.001
Environment variable: TT_FLIGHTREC_METRICS_INTERVAL

Note

Given that the average size of a metrics entry is 2 kB, you can estimate the size of the metrics storage as follows:

(flightrec_metrics_period / flightrec_metrics_interval) * 2 kB

flightrec.requests_size¶: Specify the size (in bytes) of storage for the request and response data. You can set this parameter to 0 to disable a storage of requests and responses.

Type: integer

Default: 10485760

Environment variable: TT_FLIGHTREC_REQUESTS_SIZE

flightrec.requests_max_req_size¶: Specify the maximum size (in bytes) of a request entry. A request entry is truncated if this size is exceeded.

Type: integer

Default: 16384

Environment variable: TT_FLIGHTREC_REQUESTS_MAX_REQ_SIZE

flightrec.requests_max_res_size¶: Specify the maximum size (in bytes) of a response entry. A response entry is truncated if this size is exceeded.

Type: integer

Default: 16384

Environment variable: TT_FLIGHTREC_REQUESTS_MAX_RES_SIZE

iproto

The iproto section is used to configure parameters related to communicating to and between cluster instances.

Note

iproto can be defined in any scope.

iproto.advertise.*
iproto.*
<uri>.params.*

iproto.advertise.*

iproto.advertise.client¶

A URI used to advertise the current instance to clients.

The iproto.advertise.client option accepts a URI in the following formats:

An address: host:port.
A Unix domain socket: unix/:.

Note that this option doesn’t allow to set a username and password. If a remote client needs this information, it should be delivered outside of the cluster configuration.

Note

The host value cannot be 0.0.0.0/[::] and the port value cannot be 0.

Type: string
Default: box.NULL
Environment variable: TT_IPROTO_ADVERTISE_CLIENT

iproto.advertise.peer¶

Settings used to advertise the current instance to other cluster members. The format of these settings is described in iproto.advertise.<peer_or_sharding>.*.

Example

In the example below, the following configuration options are specified:

In the credentials section, the replicator user with the replication role is created.
iproto.advertise.peer specifies that other instances should connect to an address defined in iproto.listen using the replicator user.

credentials:
  users:
    replicator:
      password: 'topsecret'
      roles: [replication]

iproto:
  advertise:
    peer:
      login: replicator

replication:
  failover: election

groups:
  group001:
    replicasets:
      replicaset001:
        instances:
          instance001:
            iproto:
              listen:
              - uri: '127.0.0.1:3301'
          instance002:
            iproto:
              listen:
              - uri: '127.0.0.1:3302'
          instance003:
            iproto:
              listen:
              - uri: '127.0.0.1:3303'

Type: map

Environment variable: see iproto.advertise.<peer_or_sharding>.*

iproto.advertise.sharding¶

Settings used to advertise the current instance to a router and rebalancer. The format of these settings is described in iproto.advertise.<peer_or_sharding>.*.

Note

If iproto.advertise.sharding is not specified, advertise settings from iproto.advertise.peer are used.

Example

In the example below, the following configuration options are specified:

In the credentials section, the replicator and storage users are created.
iproto.advertise.peer specifies that other instances should connect to an address defined in iproto.listen with the replicator user.
iproto.advertise.sharding specifies that a router should connect to storages using an address defined in iproto.listen with the storage user.

credentials:
  users:
    replicator:
      password: 'topsecret'
      roles: [replication]
    storage:
      password: 'secret'
      roles: [sharding]

iproto:
  advertise:
    peer:
      login: replicator
    sharding:
      login: storage

Type: map

Environment variable: see iproto.advertise.<peer_or_sharding>.*

iproto.advertise.<peer_or_sharding>.*

iproto.advertise.<peer_or_sharding>.uri¶: (Optional) A URI used to advertise the current instance. By default, the URI defined in iproto.listen is used to advertise the current instance.

Note

The host value cannot be 0.0.0.0/[::] and the port value cannot be 0.

Type: string

Default: nil

Environment variable: TT_IPROTO_ADVERTISE_PEER_URI, TT_IPROTO_ADVERTISE_SHARDING_URI

iproto.advertise.<peer_or_sharding>.login¶: (Optional) A username used to connect to the current instance. If a username is not set, the guest user is used.

Type: string

Default: nil

Environment variable: TT_IPROTO_ADVERTISE_PEER_LOGIN, TT_IPROTO_ADVERTISE_SHARDING_LOGIN

iproto.advertise.<peer_or_sharding>.password¶: (Optional) A password for the specified user. If a login is specified but a password is missing, it is taken from the user’s credentials.

Type: string

Default: nil

Environment variable: TT_IPROTO_ADVERTISE_PEER_PASSWORD, TT_IPROTO_ADVERTISE_SHARDING_PASSWORD

iproto.advertise.<peer_or_sharding>.params¶: (Optional) URI parameters (<uri>.params.*) required for connecting to the current instance.

iproto.*

iproto.listen¶

An array of URIs used to listen for incoming requests. If required, you can enable SSL for specific URIs by providing additional parameters (<uri>.params.*).

Note that a URI value can’t contain parameters, a login, or a password.

Example

In the example below, iproto.listen is set explicitly for each instance in a cluster:

groups:
  group001:
    replicasets:
      replicaset001:
        instances:
          instance001:
            iproto:
              listen:
              - uri: '127.0.0.1:3301'
          instance002:
            iproto:
              listen:
              - uri: '127.0.0.1:3302'
          instance003:
            iproto:
              listen:
              - uri: '127.0.0.1:3303'

<uri>.params.*

Enterprise Edition

TLS traffic encryption is supported by the Enterprise Edition only.

URI parameters that can be used in the following options:

iproto.advertise.<peer_or_sharding>.params
iproto.listen.<uri>.params

Note

Note that <uri>.params.* options don’t have corresponding environment variables for URIs specified in iproto.listen.

<uri>.params.transport¶

Allows you to enable traffic encryption for client-server communications over binary connections. In a Tarantool cluster, one instance might act as the server that accepts connections from other instances and the client that connects to other instances.

<uri>.params.transport accepts one of the following values:

plain (default): turn off traffic encryption.
ssl: encrypt traffic by using the TLS 1.2 protocol (Enterprise Edition only).

Example

The example below demonstrates how to enable traffic encryption by using a self-signed server certificate. The following parameters are specified for each instance:

ssl_cert_file: a path to an SSL certificate file.
ssl_key_file: a path to a private SSL key file.

replicaset001:
  replication:
    failover: manual
  leader: instance001
  iproto:
    advertise:
      peer:
        login: replicator
  instances:
    instance001:
      iproto:
        listen:
        - uri: '127.0.0.1:3301'
          params:
            transport: 'ssl'
            ssl_cert_file: 'certs/server.crt'
            ssl_key_file: 'certs/server.key'
    instance002:
      iproto:
        listen:
        - uri: '127.0.0.1:3302'
          params:
            transport: 'ssl'
            ssl_cert_file: 'certs/server.crt'
            ssl_key_file: 'certs/server.key'
    instance003:
      iproto:
        listen:
        - uri: '127.0.0.1:3303'
          params:
            transport: 'ssl'
            ssl_cert_file: 'certs/server.crt'
            ssl_key_file: 'certs/server.key'

You can find the full example here: ssl_without_ca.

Type: string
Default: ‘plain’
Environment variable: TT_IPROTO_ADVERTISE_PEER_PARAMS_TRANSPORT, TT_IPROTO_ADVERTISE_SHARDING_PARAMS_TRANSPORT

<uri>.params.ssl_ca_file¶

(Optional) A path to a trusted certificate authorities (CA) file. If not set, the peer won’t be checked for authenticity.

Both a server and a client can use the ssl_ca_file parameter:

If it’s on the server side, the server verifies the client.
If it’s on the client side, the client verifies the server.
If both sides have the CA files, the server and the client verify each other.

See also: <uri>.params.transport.

Type: string
Default: nil
Environment variable: TT_IPROTO_ADVERTISE_PEER_PARAMS_SSL_CA_FILE, TT_IPROTO_ADVERTISE_SHARDING_PARAMS_SSL_CA_FILE

<uri>.params.ssl_cert_file¶

A path to an SSL certificate file:

For a server, it’s mandatory.
For a client, it’s mandatory if the ssl_ca_file parameter is set for a server; otherwise, optional.

See also: <uri>.params.transport.

Type: string
Default: nil
Environment variable: TT_IPROTO_ADVERTISE_PEER_PARAMS_SSL_CERT_FILE, TT_IPROTO_ADVERTISE_SHARDING_PARAMS_SSL_CERT_FILE

<uri>.params.ssl_ciphers¶

(Optional) A colon-separated (:) list of SSL cipher suites the connection can use. Note that the list is not validated: if a cipher suite is unknown, Tarantool ignores it, doesn’t establish the connection, and writes to the log that no shared cipher was found.

The supported cipher suites are:

ECDHE-ECDSA-AES256-GCM-SHA384
ECDHE-RSA-AES256-GCM-SHA384
DHE-RSA-AES256-GCM-SHA384
ECDHE-ECDSA-CHACHA20-POLY1305
ECDHE-RSA-CHACHA20-POLY1305
DHE-RSA-CHACHA20-POLY1305
ECDHE-ECDSA-AES128-GCM-SHA256
ECDHE-RSA-AES128-GCM-SHA256
DHE-RSA-AES128-GCM-SHA256
ECDHE-ECDSA-AES256-SHA384
ECDHE-RSA-AES256-SHA384
DHE-RSA-AES256-SHA256
ECDHE-ECDSA-AES128-SHA256
ECDHE-RSA-AES128-SHA256
DHE-RSA-AES128-SHA256
ECDHE-ECDSA-AES256-SHA
ECDHE-RSA-AES256-SHA
DHE-RSA-AES256-SHA
ECDHE-ECDSA-AES128-SHA
ECDHE-RSA-AES128-SHA
DHE-RSA-AES128-SHA
AES256-GCM-SHA384
AES128-GCM-SHA256
AES256-SHA256
AES128-SHA256
AES256-SHA
AES128-SHA
GOST2012-GOST8912-GOST8912
GOST2001-GOST89-GOST89

For detailed information on SSL ciphers and their syntax, refer to OpenSSL documentation.

See also: <uri>.params.transport.

Type: string
Default: nil
Environment variable: TT_IPROTO_ADVERTISE_PEER_PARAMS_SSL_CIPHERS, TT_IPROTO_ADVERTISE_SHARDING_PARAMS_SSL_CIPHERS

<uri>.params.ssl_key_file¶

A path to a private SSL key file:

For a server, it’s mandatory.
For a client, it’s mandatory if the ssl_ca_file parameter is set for a server; otherwise, optional.

If the private key is encrypted, provide a password for it in the ssl_password or ssl_password_file parameter.

See also: <uri>.params.transport.

Type: string
Default: nil
Environment variable: TT_IPROTO_ADVERTISE_PEER_PARAMS_SSL_KEY_FILE, TT_IPROTO_ADVERTISE_SHARDING_PARAMS_SSL_KEY_FILE

<uri>.params.ssl_password¶

(Optional) A password for an encrypted private SSL key provided using ssl_key_file. Alternatively, the password can be provided in ssl_password_file.

Tarantool applies the ssl_password and ssl_password_file parameters in the following order:

If ssl_password is provided, Tarantool tries to decrypt the private key with it.
If ssl_password is incorrect or isn’t provided, Tarantool tries all passwords from ssl_password_file one by one in the order they are written.
If ssl_password and all passwords from ssl_password_file are incorrect, or none of them is provided, Tarantool treats the private key as unencrypted.

See also: <uri>.params.transport.

Type: string
Default: nil
Environment variable: TT_IPROTO_ADVERTISE_PEER_PARAMS_SSL_PASSWORD, TT_IPROTO_ADVERTISE_SHARDING_PARAMS_SSL_PASSWORD

<uri>.params.ssl_password_file¶

(Optional) A text file with one or more passwords for encrypted private SSL keys provided using ssl_key_file (each on a separate line). Alternatively, the password can be provided in ssl_password.

See also: <uri>.params.transport.

Type: string
Default: nil
Environment variable: TT_IPROTO_ADVERTISE_PEER_PARAMS_SSL_PASSWORD_FILE, TT_IPROTO_ADVERTISE_SHARDING_PARAMS_SSL_PASSWORD_FILE

groups

The groups section provides the ability to define the full topology of a Tarantool cluster.

Note

groups can be defined in the global scope only.

groups.<group_name>
groups.<group_name>.replicasets
groups.<group_name>.<config_parameter>

groups.<group_name>¶: A group name.

groups.<group_name>.replicasets¶: Replica sets that belong to this group. See replicasets.

groups.<group_name>.<config_parameter>¶: Any configuration parameter that can be defined in the group scope. For example, iproto and database configuration parameters defined at the group level are applied to all instances in this group.

replicasets

Note

replicasets can be defined in the group scope only.

replicasets.<replicaset_name>
replicasets.<replicaset_name>.leader
replicasets.<replicaset_name>.bootstrap_leader
replicasets.<replicaset_name>.instances
replicasets.<replicaset_name>.<config_parameter>

replicasets.<replicaset_name>¶: A replica set name.

replicasets.<replicaset_name>.leader¶

A replica set leader. This option can be used to set a replica set leader when manual replication.failover is used.

To perform controlled failover, <replicaset_name>.leader can be temporarily removed or set to null.

Example

replication:
  failover: manual

groups:
  group001:
    replicasets:
      replicaset001:
        leader: instance001
        instances:
          instance001:
            iproto:
              listen:
              - uri: '127.0.0.1:3301'
          instance002:
            iproto:
              listen:
              - uri: '127.0.0.1:3302'
          instance003:
            iproto:
              listen:
              - uri: '127.0.0.1:3303'

replicasets.<replicaset_name>.bootstrap_leader¶

A bootstrap leader for a replica set. To specify a bootstrap leader manually, you need to set replication.bootstrap_strategy to config.

Example

groups:
  group001:
    replicasets:
      replicaset001:
        replication:
          bootstrap_strategy: config
        bootstrap_leader: instance001
        instances:
          instance001:
            iproto:
              listen:
              - uri: '127.0.0.1:3301'
          instance002:
            iproto:
              listen:
              - uri: '127.0.0.1:3302'
          instance003:
            iproto:
              listen:
              - uri: '127.0.0.1:3303'

replicasets.<replicaset_name>.instances¶: Instances that belong to this replica set. See instances.

replicasets.<replicaset_name>.<config_parameter>¶: Any configuration parameter that can be defined in the replica set scope. For example, iproto and database configuration parameters defined at the replica set level are applied to all instances in this replica set.

instances

Note

instances can be defined in the replica set scope only.

instances.<instance_name>
instances.<instance_name>.<config_parameter>

instances.<instance_name>¶: An instance name.

instances.<instance_name>.<config_parameter>¶: Any configuration parameter that can be defined in the instance scope. For example, iproto and database configuration parameters defined at the instance level are applied to this instance only.

memtx

The memtx section is used to configure parameters related to the memtx engine.

Note

memtx can be defined in any scope.

memtx.allocator
memtx.max_tuple_size
memtx.memory
memtx.min_tuple_size
memtx.slab_alloc_factor
memtx.slab_alloc_granularity
memtx.sort_threads

memtx.allocator¶

Specify the allocator that manages memory for memtx tuples. Possible values:

system – the memory is allocated as needed, checking that the quota is not exceeded. THe allocator is based on the malloc function.
small – a slab allocator. The allocator repeatedly uses a memory block to allocate objects of the same type. Note that this allocator is prone to unresolvable fragmentation on specific workloads, so you can switch to system in such cases.

Type: string
Default: ‘small’
Environment variable: TT_MEMTX_ALLOCATOR

memtx.max_tuple_size¶: Size of the largest allocation unit for the memtx storage engine in bytes. It can be increased if it is necessary to store large tuples.

Type: integer

Default: 1048576

Environment variable: TT_MEMTX_MAX_TUPLE_SIZE

memtx.memory¶

The amount of memory in bytes that Tarantool allocates to store tuples. When the limit is reached, INSERT and UPDATE requests fail with the ER_MEMORY_ISSUE error. The server does not go beyond the memtx.memory limit to allocate tuples, but there is additional memory used to store indexes and connection information.

Example

In the example below, the memory size is set to 1 GB (1073741824 bytes).

memtx:
  memory: 1073741824

Type: integer
Default: 268435456
Environment variable: TT_MEMTX_MEMORY

memtx.min_tuple_size¶: Size of the smallest allocation unit in bytes. It can be decreased if most of the tuples are very small.

Type: integer

Default: 16

Possible values: between 8 and 1048280 inclusive

Environment variable: TT_MEMTX_MIN_TUPLE_SIZE

memtx.slab_alloc_factor¶

The multiplier for computing the sizes of memory chunks that tuples are stored in. A lower value may result in less wasted memory depending on the total amount of memory available and the distribution of item sizes.

replication

The replication section defines configuration parameters related to replication.

replication.anon
replication.bootstrap_strategy
replication.connect_timeout
replication.election_mode
replication.election_timeout
replication.election_fencing_mode
replication.failover
replication.peers
replication.skip_conflict
replication.sync_lag
replication.sync_timeout
replication.synchro_quorum
replication.synchro_timeout
replication.threads
replication.timeout

replication.anon¶: Type: boolean

Default: false

Environment variable: TT_REPLICATION_ANON

replication.bootstrap_strategy¶

Specifies a strategy used to bootstrap a replica set. The following strategies are available:

auto: a node doesn’t boot if half or more of the other nodes in a replica set are not connected. For example, if a replica set contains 2 or 3 nodes, a node requires 2 connected instances. In the case of 4 or 5 nodes, at least 3 connected instances are required. Moreover, a bootstrap leader fails to boot unless every connected node has chosen it as a bootstrap leader.
config: use the specified node to bootstrap a replica set. To specify the bootstrap leader, use the <replicaset_name>.bootstrap_leader option.
supervised: a bootstrap leader isn’t chosen automatically but should be appointed using box.ctl.make_bootstrap_leader() on the desired node.
legacy (deprecated since 2.11.0): a node requires the replication_connect_quorum number of other nodes to be connected. This option is added to keep the compatibility with the current versions of Cartridge and might be removed in the future.

Type: string
Default: auto
Environment variable: TT_REPLICATION_BOOTSTRAP_STRATEGY

replication.connect_timeout¶

A timeout (in seconds) a replica waits when trying to connect to a master in a cluster. See orphan status for details.

This parameter is different from replication.timeout, which a master uses to disconnect a replica when the master receives no acknowledgments of heartbeat messages.

Type: number
Default: 30
Environment variable: TT_REPLICATION_CONNECT_TIMEOUT

replication.election_mode¶

A role of a replica set node in the leader election process.

The possible values are:

off: a node doesn’t participate in the election activities.
voter: a node can participate in the election process but can’t be a leader.
candidate: a node should be able to become a leader.
manual: allow to control which instance is the leader explicitly instead of relying on automated leader election. By default, the instance acts like a voter – it is read-only and may vote for other candidate instances. Once box.ctl.promote() is called, the instance becomes a candidate and starts a new election round. If the instance wins the elections, it becomes a leader but won’t participate in any new elections.

Type: string
Default: box.NULL (the actual default value depends on replication.failover)
Environment variable: TT_REPLICATION_ELECTION_MODE

replication.election_timeout¶

Specifies the timeout (in seconds) between election rounds in the leader election process if the previous round ended up with a split vote.

It is quite big, and for most of the cases, it can be lowered to 300-400 ms.

To avoid the split vote repeat, the timeout is randomized on each node during every new election, from 100% to 110% of the original timeout value. For example, if the timeout is 300 ms and there are 3 nodes started the election simultaneously in the same term, they can set their election timeouts to 300, 310, and 320 respectively, or to 305, 302, and 324, and so on. In that way, the votes will never be split because the election on different nodes won’t be restarted simultaneously.

Type: number
Default: 5
Environment variable: TT_REPLICATION_ELECTION_TIMEOUT

replication.election_fencing_mode¶

Specifies the leader fencing mode that affects the leader election process. When the parameter is set to soft or strict, the leader resigns its leadership if it has less than replication.synchro_quorum of alive connections to the cluster nodes. The resigning leader receives the status of a follower in the current election term and becomes read-only.

In soft mode, a connection is considered dead if there are no responses for 4 * replication.timeout seconds both on the current leader and the followers.
In strict mode, a connection is considered dead if there are no responses for 2 * replication.timeout seconds on the current leader and 4 * replication.timeout seconds on the followers. This improves the chances that there is only one leader at any time.

Fencing applies to the instances that have the replication.election_mode set to candidate or manual. To turn off leader fencing, set election_fencing_mode to off.

Type: string
Default: soft
Possible values: off, soft, strict
Environment variable: TT_REPLICATION_ELECTION_FENCING_MODE

replication.failover¶

A failover mode used to take over a master role when the current master instance fails. The following modes are available:

off

Leadership in a replica set is controlled using the database.mode option. In this case, you can set the database.mode option to rw on all instances in a replica set to make a master-master configuration.

The default database.mode is determined as follows: rw if there is one instance in a replica set; ro if there are several instances.
manual

Leadership in a replica set is controlled using the <replicaset_name>.leader option. In this case, a master-master configuration is forbidden.

In the manual mode, the database.mode option cannot be set explicitly. The leader is configured in the read-write mode, all the other instances are read-only.
election

Automated leader election is used to control leadership in a replica set.

In the election mode, database.mode and <replicaset_name>.leader shouldn’t be set explicitly.
supervised (Enterprise Edition only)

Leadership in a replica set is controlled using an external failover agent.

In the supervised mode, database.mode and <replicaset_name>.leader shouldn’t be set explicitly.

roles

This section describes configuration parameters related to roles.

Note

Configuration parameters related to roles can be defined in any scope.

roles
roles_cfg

roles¶: Since: 3.0.0.

Type: array

Default: nil

Environment variable: TT_ROLES

roles_cfg¶: Since: 3.0.0.

Type: map

Default: nil

Environment variable: TT_ROLES_CFG

security

Enterprise Edition

Configuring security parameters is available in the Enterprise Edition only.

The security section defines configuration parameters related to various security settings.

Note

security can be defined in any scope.

security.auth_delay
security.auth_retries
security.auth_type
security.disable_guest
security.password_enforce_digits
security.password_enforce_lowercase
security.password_enforce_specialchars
security.password_enforce_uppercase
security.password_history_length
security.password_lifetime_days
security.password_min_length
security.secure_erasing

security.auth_delay¶

Specify a period of time (in seconds) that a specific user should wait for the next attempt after failed authentication.

The security.auth_retries option lets a client try to authenticate the specified number of times before security.auth_delay is enforced.

In the configuration below, Tarantool lets a client try to authenticate with the same username three times. At the fourth attempt, the authentication delay configured with security.auth_delay is enforced. This means that a client should wait 10 seconds after the first failed attempt.

security:
  auth_delay: 10
  auth_retries: 2

Type: number
Default: 0
Environment variable: TT_SECURITY_AUTH_DELAY

security.auth_retries¶

Specify the maximum number of authentication retries allowed before security.auth_delay is enforced. The default value is 0, which means security.auth_delay is enforced after the first failed authentication attempt.

The retry counter is reset after security.auth_delay seconds since the first failed attempt. For example, if a client tries to authenticate fewer than security.auth_retries times within security.auth_delay seconds, no authentication delay is enforced. The retry counter is also reset after any successful authentication attempt.

Type: integer
Default: 0
Environment variable: TT_SECURITY_AUTH_RETRIES

security.auth_type¶

Specify a protocol used to authenticate users. The possible values are:

chap-sha1: use the CHAP protocol with SHA-1 hashing applied to passwords.
pap-sha256: use PAP authentication with the SHA256 hashing algorithm.

Note that CHAP stores password hashes in the _user space unsalted. If an attacker gains access to the database, they may crack a password, for example, using a rainbow table. For PAP, a password is salted with a user-unique salt before saving it in the database, which keeps the database protected from cracking using a rainbow table.

To enable PAP, specify the security.auth_type option as follows:

security:
  auth_type: 'pap-sha256'

Type: string
Default: ‘chap-sha1’
Environment variable: TT_SECURITY_AUTH_TYPE

security.disable_guest¶: If true, turn off access over remote connections from unauthenticated or guest users. This option affects connections between cluster members and net.box connections.

Type: boolean

Default: false

Environment variable: TT_SECURITY_DISABLE_GUEST

security.password_enforce_digits¶: If true, a password should contain digits (0-9).

Type: boolean

Default: false

Environment variable: TT_SECURITY_PASSWORD_ENFORCE_DIGITS

security.password_enforce_lowercase¶: If true, a password should contain lowercase letters (a-z).

Type: boolean

Default: false

Environment variable: TT_SECURITY_PASSWORD_ENFORCE_LOWERCASE

security.password_enforce_specialchars¶: If true, a password should contain at least one special character (such as &|?!@$).

Type: boolean

Default: false

Environment variable: TT_SECURITY_PASSWORD_ENFORCE_SPECIALCHARS

security.password_enforce_uppercase¶: If true, a password should contain uppercase letters (A-Z).

Type: boolean

Default: false

Environment variable: TT_SECURITY_PASSWORD_ENFORCE_UPPERCASE

security.password_history_length¶: Specify the number of unique new user passwords before an old password can be reused.

Note

Tarantool uses the auth_history field in the box.space._user system space to store user passwords.

Type: integer

Default: 0

Environment variable: TT_SECURITY_PASSWORD_HISTORY_LENGTH

security.password_lifetime_days¶: Specify the maximum period of time (in days) a user can use the same password. When this period ends, a user gets the “Password expired” error on a login attempt. To restore access for such users, use box.schema.user.passwd.

Note

The default 0 value means that a password never expires.

Type: integer

Default: 0

Environment variable: TT_SECURITY_PASSWORD_LIFETIME_DAYS

security.password_min_length¶: Specify the minimum number of characters for a password.

Type: integer

Default: 0

Environment variable: TT_SECURITY_PASSWORD_MIN_LENGTH

security.secure_erasing¶: If true, forces Tarantool to overwrite a data file a few times before deletion to render recovery of a deleted file impossible. The option applies to both .xlog and .snap files as well as Vinyl data files.

Type: boolean

Default: false

Environment variable: TT_SECURITY_SECURE_ERASING

sharding

The sharding section defines configuration parameters related to sharding.

Note

Sharding support requires installing the vshard module. The minimum required version of vshard is 0.1.25.

sharding.bucket_count
sharding.discovery_mode
sharding.failover_ping_timeout
sharding.lock
sharding.rebalancer_disbalance_threshold
sharding.rebalancer_max_receiving
sharding.rebalancer_max_sending
sharding.roles
sharding.sched_move_quota
sharding.sched_ref_quota
sharding.shard_index
sharding.sync_timeout
sharding.zone

sharding.bucket_count¶

The total number of buckets in a cluster.

sharding.bucket_count should be several orders of magnitude larger than the potential number of cluster nodes, considering potential scaling out in the future.

If the estimated number of nodes in a cluster is M, then the data set should be divided into 100M or even 1000M buckets, depending on the planned scaling out. This number is greater than the potential number of cluster nodes in the system being designed.

Keep in mind that too many buckets can cause a need to allocate more memory to store routing information. On the other hand, an insufficient number of buckets can lead to decreased granularity when rebalancing.

Note

This option should be defined at the global level.

Example:

sharding:
  bucket_count: 1000

Type: integer
Default: 3000
Environment variable: TT_SHARDING_BUCKET_COUNT

sharding.discovery_mode¶: A mode of the background discovery fiber used by the router to find buckets. Learn more in vshard.router.discovery_set().

Note

This option should be defined at the global level.

Type: string

Default: ‘on’

Possible values: ‘on’, ‘off’, ‘once’

Environment variable: TT_SHARDING_DISCOVERY_MODE

sharding.failover_ping_timeout¶: The timeout (in seconds) after which a node is considered unavailable if there are no responses during this period. The failover fiber is used to detect if a node is down.

Note

This option should be defined at the global level.

Type: number

Default: 5

Environment variable: TT_SHARDING_FAILOVER_PING_TIMEOUT

sharding.lock¶: Whether a replica set is locked. A locked replica set cannot receive new buckets nor migrate its own buckets.

Note

sharding.lock can be specified at the replica set level or higher.

Type: boolean

Default: nil

Environment variable: TT_SHARDING_LOCK

sharding.rebalancer_disbalance_threshold¶

The maximum bucket disbalance threshold (in percent). The disbalance is calculated for each replica set using the following formula:

|etalon_bucket_count - real_bucket_count| / etalon_bucket_count * 100

Note

This option should be defined at the global level.

Type: number
Default: 1
Environment variable: TT_SHARDING_REBALANCER_DISBALANCE_THRESHOLD

sharding.rebalancer_max_receiving¶

The maximum number of buckets that can be received in parallel by a single replica set. This number must be limited because the rebalancer sends a large number of buckets from the existing replica sets to the newly added one. This produces a heavy load on the new replica set.

Note

This option should be defined at the global level.

Example:

Suppose, rebalancer_max_receiving is equal to 100 and bucket_count is equal to 1000. There are 3 replica sets with 333, 333, and 334 buckets on each respectively. When a new replica set is added, each replica set’s etalon_bucket_count becomes equal to 250. Rather than receiving all 250 buckets at once, the new replica set receives 100, 100, and 50 buckets sequentially.

Type: integer
Default: 100
Environment variable: TT_SHARDING_REBALANCER_MAX_RECEIVING

sharding.rebalancer_max_sending¶: The degree of parallelism for parallel rebalancing.

Note

This option should be defined at the global level.

Type: integer

Default: 1

Maximum: 15

Environment variable: TT_SHARDING_REBALANCER_MAX_SENDING

sharding.roles¶

Roles of a replica set in regard to sharding. A replica set can have the following roles:

router: a replica set acts as a router.
storage: a replica set acts as a storage.
rebalancer: a replica set acts as a rebalancer.

The rebalancer role is optional. If it is not specified, a rebalancer is selected automatically from master instances of replica sets.

There can be at most one replica set with the rebalancer role. Additionally, this replica set should have a storage role.

Example:

replicasets:
  storage-a:
    sharding:
      roles: [storage, rebalancer]

Note

sharding.roles can be specified at the replica set level or higher.

Type: array
Default: nil
Environment variable: TT_SHARDING_ROLES

sharding.sched_move_quota¶

A scheduler’s bucket move quota used by the rebalancer.

sched_move_quota defines how many bucket moves can be done in a row if there are pending storage refs. Then, bucket moves are blocked and a router continues making map-reduce requests.

snapshot

The snapshot section defines configuration parameters related to the snapshot files. To learn more about the snapshots’ configuration, check the Persistence page.

Note

snapshot can be defined in any scope.

snapshot.dir
snapshot.snap_io_rate_limit
snapshot.count
snapshot.by.*
- snapshot.by.interval
- snapshot.by.wal_size

snapshot.dir¶

A directory where memtx stores snapshot (.snap) files. A relative path in this option is interpreted as relative to process.work_dir.

By default, snapshots and WAL files are stored in the same directory. However, you can set different values for the snapshot.dir and wal.dir options to store them on different physical disks for performance matters.

Type: string
Default: ‘var/lib/{{ instance_name }}’
Environment variable: TT_SNAPSHOT_DIR

snapshot.snap_io_rate_limit¶: Reduce the throttling effect of box.snapshot() on INSERT/UPDATE/DELETE performance by setting a limit on how many megabytes per second it can write to disk. The same can be achieved by splitting wal.dir and snapshot.dir locations and moving snapshots to a separate disk. The limit also affects what box.stat.vinyl().regulator may show for the write rate of dumps to .run and .index files.

Type: number

Default: box.NULL

Environment variable: TT_SNAPSHOT_SNAP_IO_RATE_LIMIT

snapshot.count¶

The maximum number of snapshots that are stored in the snapshot.dir directory. If the number of snapshots after creating a new one exceeds this value, the Tarantool garbage collector deletes old snapshots. If snapshot.count is set to zero, the garbage collector does not delete old snapshots.

Example

In the example, the checkpoint daemon creates a snapshot every two hours until it has created three snapshots. After creating a new snapshot (the fourth one), the oldest snapshot and any associated write-ahead-log files are deleted.

snapshot:
  by:
    interval: 7200
  count: 3

Note

Snapshots will not be deleted if replication is ongoing and the file has not been relayed to a replica. Therefore, snapshot.count has no effect unless all replicas are alive.

Type: integer
Default: 2
Environment variable: TT_SNAPSHOT_COUNT

snapshot.by.*

snapshot.by.interval¶

The interval in seconds between actions by the checkpoint daemon. If the option is set to a value greater than zero, and there is activity that causes change to a database, then the checkpoint daemon calls box.snapshot() every snapshot.by.interval seconds, creating a new snapshot file each time. If the option is set to zero, the checkpoint daemon is disabled.

Example

In the example, the checkpoint daemon creates a new database snapshot every two hours, if there is activity.

by:
  interval: 7200

Type: number
Default: 3600
Environment variable: TT_SNAPSHOT_BY_INTERVAL

snapshot.by.wal_size¶: The threshold for the total size in bytes for all WAL files created since the last snapshot taken. Once the configured threshold is exceeded, the WAL thread notifies the checkpoint daemon that it must make a new snapshot and delete old WAL files.

Type: integer

Default: 10^18

Environment variable: TT_SNAPSHOT_BY_WAL_SIZE

wal

The wal section defines configuration parameters related to write-ahead log. To learn more about the WAL configuration, check the Persistence page.

Note

wal can be defined in any scope.

wal.cleanup_delay
wal.dir
wal.dir_rescan_delay
wal.max_size
wal.mode
wal.queue_max_size
wal.ext.*

wal.cleanup_delay¶: The delay in seconds used to prevent the Tarantool garbage collector from immediately removing write-ahead log files after a node restart. This delay eliminates possible erroneous situations when the master deletes WALs needed by replicas after restart. As a consequence, replicas sync with the master faster after its restart and don’t need to download all the data again. Once all the nodes in the replica set are up and running, a scheduled garbage collection is started again even if wal.cleanup_delay has not expired.

Note

The option has no effect on nodes running as anonymous replicas.

Type: number

Default: 14400

Environment variable: TT_WAL_CLEANUP_DELAY

wal.dir¶

A directory where write-ahead log (.xlog) files are stored. A relative path in this option is interpreted as relative to process.work_dir.

By default, WAL files and snapshots are stored in the same directory. However, you can set different values for the wal.dir and snapshot.dir options to store them on different physical disks for performance matters.

Type: string
Default: ‘var/lib/{{ instance_name }}’
Environment variable: TT_WAL_DIR

wal.dir_rescan_delay¶: The time interval in seconds between periodic scans of the write-ahead-log file directory, when checking for changes to write-ahead-log files for the sake of replication or hot standby.

Type: number

Default: 2

Environment variable: TT_WAL_DIR_RESCAN_DELAY

wal.max_size¶: The maximum number of bytes in a single write-ahead log file. When a request would cause an .xlog file to become larger than wal.max_size, Tarantool creates a new WAL file.

Type: integer

Default: 268435456

Environment variable: TT_WAL_MAX_SIZE

wal.mode¶

Specify fiber-WAL-disk synchronization mode as:

none: write-ahead log is not maintained. A node with wal.mode set to none can’t be a replication master.
write: fibers wait for their data to be written to the write-ahead log (no fsync(2)).
fsync: fibers wait for their data, fsync(2) follows each write(2).

Type: string
Default: ‘write’
Environment variable: TT_WAL_MODE

wal.queue_max_size¶

The size of the queue in bytes used by a replica to submit new transactions to a write-ahead log (WAL). This option helps limit the rate at which a replica submits transactions to the WAL.

Limiting the queue size might be useful when a replica is trying to sync with a master and reads new transactions faster than writing them to the WAL.

Note

You might consider increasing the wal.queue_max_size value in case of large tuples (approximately one megabyte or larger).

Type: integer
Default: 16777216
Environment variable: TT_WAL_QUEUE_MAX_SIZE

wal.ext.*

Enterprise Edition

Configuring wal.ext.* parameters is available in the Enterprise Edition only.

This section describes options related to WAL extensions.

wal.ext.new¶: Enable storing a new tuple for each CRUD operation performed. The option is in effect for all spaces. To adjust the option for specific spaces, use the wal.ext.spaces option.

Type: boolean

Default: false

Environment variable: TT_WAL_EXT_NEW

wal.ext.old¶: Enable storing an old tuple for each CRUD operation performed. The option is in effect for all spaces. To adjust the option for specific spaces, use the wal.ext.spaces option.

Type: boolean

Default: false

Environment variable: TT_WAL_EXT_OLD

wal.ext.spaces¶

Enable or disable storing an old and new tuple in the WAL record for a given space explicitly. The configuration for specific spaces has priority over the configuration in the wal.ext.new and wal.ext.old options.

The option is a key-value pair:

The key is a space name (string).
The value is a table that includes two optional boolean options: old and new. The format and the default value of these options are described in wal.ext.old and wal.ext.new.

Example

In the example, only new tuples are added to the log for the bands space.

ext:
  new: true
  old: true
  spaces:
    bands:
      old: false

Type: map
Default: nil
Environment variable: TT_WAL_EXT_SPACES

Version:

Configuration reference

audit_log

audit_log.syslog.*

config

config.context.*

config.etcd.*

config.storage.*

credentials

credentials.roles.*

credentials.users.*

<user_or_role_name>.privileges.*

database

flightrec

iproto

iproto.advertise.*

iproto.advertise.<peer_or_sharding>.*

iproto.*

<uri>.params.*

groups

replicasets

instances

memtx

replication

roles

security

sharding

snapshot

snapshot.by.*

wal

wal.ext.*