Node-specific settings

Table of contents

Basics

cluster.name
Default: crate
Runtime: no

The name of the CrateDB cluster the node should join to.

node.name
Runtime: no

The name of the node. If no name is configured a random one will be generated.

Note

Node names must be unique in a CrateDB cluster.

node.store.allow_mmap
Default: true
Runtime: no

The setting indicates whether or not memory-mapping is allowed.

Node types

CrateDB supports different types of nodes.

The following settings can be used to differentiate nodes upon startup:

node.master
Default: true
Runtime: no

Whether or not this node is able to get elected as master node in the cluster.

node.data
Default: true
Runtime: no

Whether or not this node will store data.

Using different combinations of these two settings, you can create four different types of node. Each type of node is differentiated by what types of load it will handle.

Tabulating the truth values for node.master and node.data produces a truth table outlining the four different types of node:

Master

No master

Data

Handle all loads.

Handles client requests and query execution.

No data

Handles cluster management.

Handles client requests.

Nodes marked as node.master will only handle cluster management if they are elected as the cluster master. All other loads are shared equally.

General

node.sql.read_only
Default: false
Runtime: no

If set to true, the node will only allow SQL statements which are resulting in read operations.

statement_timeout
Default: 0
Runtime: yes

The maximum duration of any statement before it gets cancelled.

This value is used as default value for the statement_timeout session setting

If 0 queries are allowed to run infinitely and don’t get cancelled automatically.

Note

Updating this setting won’t affect existing sessions, it will only take effect for new sessions.

Networking

Hosts

network.host
Default: _local_
Runtime: no

The IP address CrateDB will bind itself to. This setting sets both the network.bind_host and network.publish_host values.

network.bind_host
Default: _local_
Runtime: no

This setting determines to which address CrateDB should bind itself to.

network.publish_host
Default: _local_
Runtime: no

This setting is used by a CrateDB node to publish its own address to the rest of the cluster.

Tip

Apart from IPv4 and IPv6 addresses there are some special values that can be used for all above settings:

_local_

Any loopback addresses on the system, for example 127.0.0.1.

_site_

Any site-local addresses on the system, for example 192.168.0.1.

_global_

Any globally-scoped addresses on the system, for example 8.8.8.8.

_[INTERFACE]_

Addresses of a network interface, for example _en0_.

Ports

http.port
Runtime: no

This defines the TCP port range to which the CrateDB HTTP service will be bound to. It defaults to 4200-4300. Always the first free port in this range is used. If this is set to an integer value it is considered as an explicit single port.

The HTTP protocol is used for the REST endpoint which is used by all clients except the Java client.

http.publish_port
Runtime: no

The port HTTP clients should use to communicate with the node. It is necessary to define this setting if the bound HTTP port (http.port) of the node is not directly reachable from outside, e.g. running it behind a firewall or inside a Docker container.

transport.tcp.port
Runtime: no

This defines the TCP port range to which the CrateDB transport service will be bound to. It defaults to 4300-4400. Always the first free port in this range is used. If this is set to an integer value it is considered as an explicit single port.

The transport protocol is used for internal node-to-node communication.

transport.publish_port
Runtime: no

The port that the node publishes to the cluster for its own discovery. It is necessary to define this setting when the bound tranport port (transport.tcp.port) of the node is not directly reachable from outside, e.g. running it behind a firewall or inside a Docker container.

psql.port
Runtime: no

This defines the TCP port range to which the CrateDB Postgres service will be bound to. It defaults to 5432-5532. Always the first free port in this range is used. If this is set to an integer value it is considered as an explicit single port.

Advanced TCP settings

Any interface that uses TCP (Postgres wire, HTTP & Transport protocols) shares the following settings:

network.tcp.no_delay
Default: true
Runtime: no

Enable or disable the Nagle’s algorithm for buffering TCP packets. Buffering is disabled by default.

network.tcp.keep_alive
Default: true
Runtime: no

Configures the SO_KEEPALIVE option for sockets, which determines whether they send TCP keepalive probes.

network.tcp.reuse_address
Default: true on non-windows machines and false otherwise
Runtime: no

Configures the SO_REUSEADDRS option for sockets, which determines whether they should reuse the address.

network.tcp.send_buffer_size
Default: -1
Runtime: no

The size of the TCP send buffer (SO_SNDBUF socket option). By default not explicitly set.

network.tcp.receive_buffer_size
Default: -1
Runtime: no

The size of the TCP receive buffer (SO_RCVBUF socket option). By default not explicitly set.

Note

Each setting in this section has its counterpart for HTTP and transport. To provide a protocol specific setting, remove network prefix and use either http or transport instead. For example, no_delay can be configured as http.tcp.no_delay and transport.tcp.no_delay. Please note, that PG interface takes its settings from transport.

Transport settings

transport.connect_timeout
Default: 30s
Runtime: no

The connect timeout for initiating a new connection.

transport.compress
Default: false
Runtime: no

Set to true to enable compression (DEFLATE) between all nodes.

transport.ping_schedule
Default: -1
Runtime: no

Schedule a regular application-level ping message to ensure that transport connections between nodes are kept alive. Defaults to -1 (disabled). It is preferable to correctly configure TCP keep-alives instead of using this feature, because TCP keep-alives apply to all kinds of long-lived connections and not just to transport connections.

Paths

Note

Relative paths are relative to CRATE_HOME. Absolute paths override this behavior.

path.conf
Default: config
Runtime: no

Filesystem path to the directory containing the configuration files crate.yml and log4j2.properties.

path.data
Default: data
Runtime: no

Filesystem path to the directory where this CrateDB node stores its data (table data and cluster metadata).

Multiple paths can be set by using a comma separated list and each of these paths will hold full shards (instead of striping data across them). For example:

path.data: /path/to/data1,/path/to/data2

When CrateDB finds striped shards at the provided locations (from CrateDB <0.55.0), these shards will be migrated automatically on startup.

path.logs
Default: logs
Runtime: no

Filesystem path to a directory where log files should be stored.

Can be used as a variable inside log4j2.properties.

For example:

appender:
  file:
    file: ${path.logs}/${cluster.name}.log
path.repo
Runtime: no

A list of filesystem or UNC paths where repositories of type fs may be stored.

Without this setting a CrateDB user could write snapshot files to any directory that is writable by the CrateDB process. To safeguard against this security issue, the possible paths have to be whitelisted here.

See also location setting of repository type fs.

See also

blobs.path

Plug-ins

plugin.mandatory
Runtime: no

A list of plug-ins that are required for a node to startup.

If any plug-in listed here is missing, the CrateDB node will fail to start.

CPU

processors
Runtime: no

The number of processors is used to set the size of the thread pools CrateDB is using appropriately. If not set explicitly, CrateDB will infer the number from the available processors on the system.

In environments where the CPU amount can be restricted (like Docker) or when multiple CrateDB instances are running on the same hardware, the inferred number might be too high. In such a case, it is recommended to set the value explicitly.

Memory

bootstrap.memory_lock
Default: false
Runtime: no

CrateDB performs poorly when the JVM starts swapping: you should ensure that it never swaps. If set to true, CrateDB will use the mlockall system call on startup to ensure that the memory pages of the CrateDB process are locked into RAM.

Garbage collection

CrateDB logs if JVM garbage collection on different memory pools takes too long. The following settings can be used to adjust these timeouts:

monitor.jvm.gc.collector.young.warn
Default: 1000ms
Runtime: no

CrateDB will log a warning message if it takes more than the configured timespan to collect the Eden Space (heap).

monitor.jvm.gc.collector.young.info
Default: 700ms
Runtime: no

CrateDB will log an info message if it takes more than the configured timespan to collect the Eden Space (heap).

monitor.jvm.gc.collector.young.debug
Default: 400ms
Runtime: no

CrateDB will log a debug message if it takes more than the configured timespan to collect the Eden Space (heap).

monitor.jvm.gc.collector.old.warn
Default: 10000ms
Runtime: no

CrateDB will log a warning message if it takes more than the configured timespan to collect the Old Gen / Tenured Gen (heap).

monitor.jvm.gc.collector.old.info
Default: 5000ms
Runtime: no

CrateDB will log an info message if it takes more than the configured timespan to collect the Old Gen / Tenured Gen (heap).

monitor.jvm.gc.collector.old.debug
Default: 2000ms
Runtime: no

CrateDB will log a debug message if it takes more than the configured timespan to collect the Old Gen / Tenured Gen (heap).

Authentication

Trust authentication

auth.trust.http_default_user
Default: crate
Runtime: no

The default user that should be used for authentication when clients connect to CrateDB via HTTP protocol and they do not specify a user via the Authorization request header.

auth.trust.http_support_x_real_ip
Default: false
Runtime: no

If enabled, the HTTP transport will trust the X-Real-IP header sent by the client to determine the client’s IP address. This is useful when CrateDB is running behind a reverse proxy or load-balancer. For improved security, any _local_ IP address (127.0.0.1 and ::1) defined in this header will be ignored.

Warning

Enabling this setting can be a security risk, as it allows clients to impersonate other clients by sending a fake X-Real-IP header.

Host-based authentication

Authentication settings (auth.host_based.*) are node settings, which means that their values apply only to the node where they are applied and different nodes may have different authentication settings.

auth.host_based.enabled
Default: false
Runtime: no

Setting to enable or disable Host Based Authentication (HBA). It is disabled by default.

HBA entries

The auth.host_based.config. setting is a group setting that can have zero, one or multiple groups that are defined by their group key (${order}) and their fields (user, address, method, protocol, ssl).

${order}:
An identifier that is used as a natural order key when looking up the host
based configuration entries. For example, an order key of a will be
looked up before an order key of b. This key guarantees that the entry
lookup order will remain independent from the insertion order of the
entries.

The Host-Based Authentication (HBA) setting is a list of predicates that users can specify to restrict or allow access to CrateDB.

The meaning of the fields of the are as follows:

auth.host_based.config.${order}.user
Runtime: no
Specifies an existing CrateDB username, only crate user (superuser) is
available. If no user is specified in the entry, then all existing users
can have access.
auth.host_based.config.${order}.address
Runtime: no
The client machine addresses that the client matches, and which are allowed
to authenticate. This field may contain an IPv4 address, an IPv6 address or
an IPv4 CIDR mask. For example: 127.0.0.1 or 127.0.0.1/32. It also
may contain a hostname or the special _local_ notation which will match
both IPv4 and IPv6 connections from localhost. A hostname specification
that starts with a dot (.) matches a suffix of the actual hostname.
So .crate.io would match foo.crate.io but not just crate.io. If no address
is specified in the entry, then access to CrateDB is open for all hosts.
auth.host_based.config.${order}.method
Runtime: no
The authentication method to use when a connection matches this entry.
Valid values are trust, cert, password and jwt. If no
method is specified, the trust method is used by default.
JWT authentication method for more information about these methods.
auth.host_based.config.${order}.protocol
Runtime: no
Specifies the protocol for which the authentication entry should be used.
If no protocol is specified, then this entry will be valid for all
protocols that rely on host based authentication see Trust method).
auth.host_based.config.${order}.ssl
Default: optional
Runtime: no
Specifies whether the client must use SSL/TLS to connect to the cluster.
If set to on then the client must be connected through SSL/TLS
otherwise is not authenticated. If set to off then the client must
not be connected via SSL/TLS otherwise is not authenticated. Finally
optional, which is the value when the option is completely skipped,
means that the client can be authenticated regardless of SSL/TLS is used
or not.

Example of config groups:

auth.host_based.config:
  entry_a:
    user: crate
    address: 127.16.0.0/16
  entry_b:
    method: trust
  entry_3:
    user: crate
    address: 172.16.0.0/16
    method: trust
    protocol: pg
    ssl: on

Secured communications (SSL/TLS)

Secured communications via SSL allows you to encrypt traffic between CrateDB nodes and clients connecting to them. Connections are secured using Transport Layer Security (TLS).

ssl.http.enabled
Default: false
Runtime: no

Set this to true to enable secure communication between the CrateDB node and the client through SSL via the HTTPS protocol.

ssl.psql.enabled
Default: false
Runtime: no

Set this to true to enable secure communication between the CrateDB node and the client through SSL via the PostgreSQL wire protocol.

ssl.transport.mode
Default: legacy
Runtime: no

For communication between nodes, choose:

off

SSL cannot be used

legacy

SSL is not used. If HBA is enabled, transport connections won’t be verified Any reachable host can establish a connection.

on

SSL must be used

ssl.keystore_filepath
Runtime: no

The full path to the node keystore file.

ssl.keystore_password
Runtime: no

The password used to decrypt the keystore file defined with ssl.keystore_filepath.

ssl.keystore_key_password
Runtime: no

The password entered at the end of the keytool -genkey command.

Note

Optionally trusted CA certificates can be stored separately from the node’s keystore into a truststore for CA certificates.

ssl.truststore_filepath
Runtime: no

The full path to the node truststore file. If not defined, then only a keystore will be used.

ssl.truststore_password
Runtime: no

The password used to decrypt the truststore file defined with ssl.truststore_filepath.

ssl.resource_poll_interval
Default: 5m
Runtime: no

The frequency at which SSL files such as keystore and truststore are polled for changes.

Cross-origin resource sharing (CORS)

Many browsers support the same-origin policy which requires web applications to explicitly allow requests across origins. The cross-origin resource sharing settings in CrateDB allow for configuring these.

http.cors.enabled
Default: false
Runtime: no

Enable or disable cross-origin resource sharing.

http.cors.allow-origin
Default: <empty>
Runtime: no

Define allowed origins of a request. * allows any origin (which can be a substantial security risk) and by prepending a / the string will be treated as a regular expression. For example /https?:\/\/crate.io/ will allow requests from https://crate.io and https://crate.io. This setting disallows any origin by default.

http.cors.max-age
Default: 1728000 (20 days)
Runtime: no

Max cache age of a preflight request in seconds.

http.cors.allow-methods
Default: OPTIONS, HEAD, GET, POST, PUT, DELETE
Runtime: no

Allowed HTTP methods.

http.cors.allow-headers
Default: X-Requested-With, Content-Type, Content-Length
Runtime: no

Allowed HTTP headers.

http.cors.allow-credentials
Default: false
Runtime: no

Add the Access-Control-Allow-Credentials header to responses.

Blobs

blobs.path
Runtime: no

Path to a filesystem directory where to store blob data allocated for this node.

By default blobs will be stored under the same path as normal data. A relative path value is interpreted as relative to CRATE_HOME.

Repositories

Repositories are used to backup a CrateDB cluster.

repositories.url.allowed_urls
Runtime: no

This setting only applies to repositories of type url.

With this setting a list of urls can be specified which are allowed to be used if a repository of type url is created.

Wildcards are supported in the host, path, query and fragment parts.

This setting is a security measure to prevent access to arbitrary resources.

In addition, the supported protocols can be restricted using the repositories.url.supported_protocols setting.

repositories.url.supported_protocols
Default: http, https, ftp, file and jar
Runtime: no

A list of protocols that are supported by repositories of type url.

The jar protocol is used to access the contents of jar files. For more info, see the java JarURLConnection documentation.

See also the path.repo Setting.

Queries

indices.query.bool.max_clause_count
Default: 8192
Runtime: no

This setting limits the number of boolean clauses that can be generated by != ANY(), LIKE ANY(), ILIKE ANY(), NOT LIKE ANY() and NOT ILIKE ANY() operators on arrays in order to prevent users from executing queries that may result in heavy memory consumption causing nodes to crash with OutOfMemory exceptions. Throws TooManyClauses errors when the limit is exceeded.

Note

You can avoid TooManyClauses errors by increasing this setting. The number of boolean clauses used can be larger than the elements of the array .

Legacy

legacy.table_function_column_naming
Default: false
Runtime: no

Since CrateDB 5.0.0, if the table function is not aliased and is returning a single base data typed column, the table function name is used as the column name. This setting can be set in order to use the naming convention prior to 5.0.0.

The following table functions are affected by this setting:

When the setting is set and a single column is expected to be returned, the returned column will be named col1, groups, or col1 respectively.

Note

Beware that if not all nodes in the cluster are consistently set or unset, the behaviour will depend on the node handling the query.

JavaScript language

lang.js.enabled
Default: true
Runtime: no

Setting to enable or disable JavaScript UDF support.

Foreign Data Wrappers

fdw.allow_local
Default: false
Runtime: no

Allow access to local addresses via Foreign data wrappers for all users.

By default, only the crate superuser is allowed to access foreign servers that point to localhost.

Warning

Changing this to true can pose a security risk if you do not trust the users with AL permissions on the system. They can create foreign servers, foreign tables and user mappings that allow them to access services running on the same machine as CrateDB as if connected locally - effectively bypassing any restrictions set up via Host-Based Authentication (HBA).

Do not change this if you don’t understand the implications.

Custom attributes

The node.attr namespace is a bag of custom attributes. Custom attributes can be used to control shard allocation.

You can create any attribute you want under this namespace, like node.attr.key: value. These attributes use the node.attr namespace to distinguish them from core node attribute like node.name.

Custom attributes are not validated by CrateDB, unlike core node attributes.