elasticsearch/docs/reference/modules/http.asciidoc

[[http-settings]]
==== Advanced HTTP settings

Use the following advanced settings to configure the HTTP interface
independently of the <<transport-settings,transport interface>>. You can also
configure both interfaces together using the <<common-network-settings,network settings>>.

`http.host`::
(<<static-cluster-setting,Static>>)
Sets the address of this node for HTTP traffic. The node will bind to this
address and will also use it as its HTTP publish address. Accepts an IP
address, a hostname, or a <<network-interface-values,special value>>.
Use this setting only if you require different configurations for the
transport and HTTP interfaces.
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Defaults to the address given by `network.host`.

`http.bind_host`::
(<<static-cluster-setting,Static>>)
The network address(es) to which the node should bind in order to listen for
incoming HTTP connections. Accepts a list of IP addresses, hostnames, and
<<network-interface-values,special values>>. Defaults to the address given by
`http.host` or `network.bind_host`. Use this setting only if you require to
bind to multiple addresses or to use different addresses for publishing and
binding, and you also require different binding configurations for the
transport and HTTP interfaces.

`http.publish_host`::
(<<static-cluster-setting,Static>>)
The network address for HTTP clients to contact the node using sniffing.
Accepts an IP address, a hostname, or a <<network-interface-values,special
value>>. Defaults to the address given by `http.host` or
`network.publish_host`. Use this setting only if you require to bind to
multiple addresses or to use different addresses for publishing and binding,
and you also require different binding configurations for the transport and
HTTP interfaces.

`http.publish_port`::
(<<static-cluster-setting,Static>>)
The port of the <<modules-network-binding-publishing,HTTP publish address>>.
Configure this setting only if you need the publish port to be different from
`http.port`. Defaults to the port assigned via `http.port`.

`http.max_content_length`::
(<<static-cluster-setting,Static>>)
Maximum size of an HTTP request body. Defaults to `100mb`.

`http.max_initial_line_length`::
(<<static-cluster-setting,Static>>)
Maximum size of an HTTP URL. Defaults to `4kb`.

`http.max_header_size`::
(<<static-cluster-setting,Static>>)
Maximum size of allowed headers. Defaults to `8kb`.

[[http-compression]]
// tag::http-compression-tag[]
`http.compression` {ess-icon}::
(<<static-cluster-setting,Static>>)
Support for compression when possible (with Accept-Encoding). If HTTPS is enabled, defaults to `false`. Otherwise, defaults to `true`.
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Disabling compression for HTTPS mitigates potential security risks, such as a
{wikipedia}/BREACH[BREACH attack]. To compress HTTPS traffic,
you must explicitly set `http.compression` to `true`.
// end::http-compression-tag[]

`http.compression_level`::
(<<static-cluster-setting,Static>>)
Defines the compression level to use for HTTP responses. Valid values are in the range of 1 (minimum compression) and 9 (maximum compression). Defaults to `3`.

[[http-cors-enabled]]
// tag::http-cors-enabled-tag[]
`http.cors.enabled` {ess-icon}::
(<<static-cluster-setting,Static>>)
Enable or disable cross-origin resource sharing, which determines whether a browser on another origin can execute requests against {es}. Set to `true` to enable {es} to process pre-flight
{wikipedia}/Cross-origin_resource_sharing[CORS] requests.
{es} will respond to those requests with the `Access-Control-Allow-Origin` header if the `Origin` sent in the request is permitted by the `http.cors.allow-origin` list. Set to `false` (the default) to make {es} ignore the `Origin` request header, effectively disabling CORS requests because {es} will never respond with the `Access-Control-Allow-Origin` response header.
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NOTE: If the client does not send a pre-flight request with an `Origin` header or it does not check the response headers from the server to validate the
`Access-Control-Allow-Origin` response header, then cross-origin security is
compromised. If CORS is not enabled on {es}, the only way for the client to know is to send a pre-flight request and realize the required response headers are missing.

// end::http-cors-enabled-tag[]

[[http-cors-allow-origin]]
// tag::http-cors-allow-origin-tag[]
`http.cors.allow-origin` {ess-icon}::
(<<static-cluster-setting,Static>>)
Which origins to allow. If you prepend and append a forward slash (`/`) to the value, this will be treated as a regular expression, allowing you to support HTTP and HTTPs. For example, using `/https?:\/\/localhost(:[0-9]+)?/` would return the request header appropriately in both cases. Defaults to no origins allowed.
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IMPORTANT: A wildcard (`*`) is a valid value but is considered a security risk, as your {es} instance is open to cross origin requests from *anywhere*.

// end::http-cors-allow-origin-tag[]

[[http-cors-max-age]]
// tag::http-cors-max-age-tag[]
`http.cors.max-age` {ess-icon}::
(<<static-cluster-setting,Static>>)
Browsers send a "preflight" OPTIONS-request to determine CORS settings. `max-age` defines how long the result should be cached for. Defaults to `1728000` (20 days).
// end::http-cors-max-age-tag[]

[[http-cors-allow-methods]]
// tag::http-cors-allow-methods-tag[]
`http.cors.allow-methods` {ess-icon}::
(<<static-cluster-setting,Static>>)
Which methods to allow. Defaults to `OPTIONS, HEAD, GET, POST, PUT, DELETE`.
// end::http-cors-allow-methods-tag[]

[[http-cors-allow-headers]]
// tag::http-cors-allow-headers-tag[]
`http.cors.allow-headers` {ess-icon}::
(<<static-cluster-setting,Static>>)
Which headers to allow. Defaults to `X-Requested-With, Content-Type, Content-Length`.
// end::http-cors-allow-headers-tag[]

[[http-cors-allow-credentials]]
// tag::http-cors-allow-credentials-tag[]
`http.cors.allow-credentials` {ess-icon}::
(<<static-cluster-setting,Static>>)
Whether the `Access-Control-Allow-Credentials` header should be returned. Defaults to `false`.
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NOTE: This header is only returned when the setting is set to `true`.

// end::http-cors-allow-credentials-tag[]

`http.detailed_errors.enabled`::
(<<static-cluster-setting,Static>>)
If `true`, enables the output of detailed error messages and stack traces in the response output. Defaults to `true`.
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If `false`, use the `error_trace` parameter to <<common-options-error-options,enable stack traces>> and return detailed error messages. Otherwise, only a simple message will be returned.

`http.pipelining.max_events`::
(<<static-cluster-setting,Static>>)
The maximum number of events to be queued up in memory before an HTTP connection is closed, defaults to `10000`.

`http.max_warning_header_count`::
(<<static-cluster-setting,Static>>)
The maximum number of warning headers in client HTTP responses. Defaults to `unbounded`.

`http.max_warning_header_size`::
(<<static-cluster-setting,Static>>)
The maximum total size of warning headers in client HTTP responses. Defaults to `unbounded`.

`http.tcp.no_delay`::
(<<static-cluster-setting,Static>>)
Enable or disable the {wikipedia}/Nagle%27s_algorithm[TCP no delay]
setting. Defaults to `network.tcp.no_delay`.

`http.tcp.keep_alive`::
(<<static-cluster-setting,Static>>)
Configures the `SO_KEEPALIVE` option for this socket, which
determines whether it sends TCP keepalive probes.
Defaults to `network.tcp.keep_alive`.

`http.tcp.keep_idle`::
(<<static-cluster-setting,Static>>) Configures the `TCP_KEEPIDLE` option for this socket, which
determines the time in seconds that a connection must be idle before
starting to send TCP keepalive probes. Defaults to `network.tcp.keep_idle`, which
uses the system default. This value cannot exceed `300` seconds. Only applicable on
Linux and macOS, and requires Java 11 or newer.

`http.tcp.keep_interval`::
(<<static-cluster-setting,Static>>) Configures the `TCP_KEEPINTVL` option for this socket,
which determines the time in seconds between sending TCP keepalive probes.
Defaults to `network.tcp.keep_interval`, which uses the system default.
This value cannot exceed `300` seconds. Only applicable on Linux and macOS, and requires
Java 11 or newer.

`http.tcp.keep_count`::
(<<static-cluster-setting,Static>>) Configures the `TCP_KEEPCNT` option for this socket, which
determines the number of unacknowledged TCP keepalive probes that may be
sent on a connection before it is dropped. Defaults to `network.tcp.keep_count`,
which uses the system default. Only applicable on Linux and macOS, and
requires Java 11 or newer.

`http.tcp.reuse_address`::
(<<static-cluster-setting,Static>>)
Should an address be reused or not. Defaults to `network.tcp.reuse_address`.

`http.tcp.send_buffer_size`::
(<<static-cluster-setting,Static>>)
The size of the TCP send buffer (specified with <<size-units,size units>>).
Defaults to `network.tcp.send_buffer_size`.

`http.tcp.receive_buffer_size`::
(<<static-cluster-setting,Static>>)
The size of the TCP receive buffer (specified with <<size-units,size units>>).
Defaults to `network.tcp.receive_buffer_size`.

`http.client_stats.enabled`::
(<<dynamic-cluster-setting,Dynamic>>)
Enable or disable collection of HTTP client stats. Defaults to `true`.