159 lines
6.9 KiB
Plaintext
159 lines
6.9 KiB
Plaintext
[[modules-http]]
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=== HTTP
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[[modules-http-description]]
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// tag::modules-http-description-tag[]
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The HTTP layer exposes {es}'s REST APIs over HTTP.
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The HTTP mechanism is completely asynchronous in nature, meaning that
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there is no blocking thread waiting for a response. The benefit of using
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asynchronous communication for HTTP is solving the
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http://en.wikipedia.org/wiki/C10k_problem[C10k problem].
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When possible, consider using
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http://en.wikipedia.org/wiki/Keepalive#HTTP_Keepalive[HTTP keep alive]
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when connecting for better performance and try to get your favorite
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client not to do
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http://en.wikipedia.org/wiki/Chunked_transfer_encoding[HTTP chunking].
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// end::modules-http-description-tag[]
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[http-settings]
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==== HTTP settings
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The following settings can be configured for HTTP. These settings also use the common <<modules-network,network settings>>.
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NOTE: HTTP settings cannot be updated dynamically. You must configure these settings in the {es} <<settings, configuration file>>
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and restart {es} for changes to take effect.
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`http.port`::
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A bind port range. Defaults to `9200-9300`.
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`http.publish_port`::
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The port that HTTP clients should use when
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communicating with this node. Useful when a cluster node is behind a
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proxy or firewall and the `http.port` is not directly addressable
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from the outside. Defaults to the actual port assigned via `http.port`.
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`http.bind_host`::
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The host address to bind the HTTP service to. Defaults to `http.host` (if set) or `network.bind_host`.
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`http.publish_host`::
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The host address to publish for HTTP clients to connect to. Defaults to `http.host` (if set) or `network.publish_host`.
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`http.host`::
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Used to set the `http.bind_host` and the `http.publish_host`.
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`http.max_content_length`::
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The max content of an HTTP request. Defaults to `100MB`.
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`http.max_initial_line_length`::
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The max length of an HTTP URL. Defaults to `4KB`.
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`http.max_header_size`::
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The max size of allowed headers. Defaults to `8KB`.
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[[http-compression]]
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// tag::http-compression-tag[]
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`http.compression` {ess-icon}::
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Support for compression when possible (with Accept-Encoding). If HTTPS is enabled, defaults to `false`. Otherwise, defaults to `true`.
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+
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Disabling compression for HTTPS mitigates potential security risks, such as a
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https://en.wikipedia.org/wiki/BREACH[BREACH attack]. To compress HTTPS traffic,
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you must explicitly set `http.compression` to `true`.
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// end::http-compression-tag[]
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`http.compression_level`::
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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`.
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[[http-cors-enabled]]
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// tag::http-cors-enabled-tag[]
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`http.cors.enabled` {ess-icon}::
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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
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https://en.wikipedia.org/wiki/Cross-origin_resource_sharing[CORS] requests.
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{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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+
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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
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`Access-Control-Allow-Origin` response header, then cross-origin security is
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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.
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// end::http-cors-enabled-tag[]
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[[http-cors-allow-origin]]
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// tag::http-cors-allow-origin-tag[]
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`http.cors.allow-origin` {ess-icon}::
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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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+
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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*.
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// end::http-cors-allow-origin-tag[]
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[[http-cors-max-age]]
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// tag::http-cors-max-age-tag[]
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`http.cors.max-age` {ess-icon}::
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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).
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// end::http-cors-max-age-tag[]
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[[http-cors-allow-methods]]
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// tag::http-cors-allow-methods-tag[]
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`http.cors.allow-methods` {ess-icon}::
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Which methods to allow. Defaults to `OPTIONS, HEAD, GET, POST, PUT, DELETE`.
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// end::http-cors-allow-methods-tag[]
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[[http-cors-allow-headers]]
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// tag::http-cors-allow-headers-tag[]
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`http.cors.allow-headers` {ess-icon}::
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Which headers to allow. Defaults to `X-Requested-With, Content-Type, Content-Length`.
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// end::http-cors-allow-headers-tag[]
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[[http-cors-allow-credentials]]
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// tag::http-cors-allow-credentials-tag[]
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`http.cors.allow-credentials` {ess-icon}::
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Whether the `Access-Control-Allow-Credentials` header should be returned. Defaults to `false`.
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+
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NOTE: This header is only returned when the setting is set to `true`.
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// end::http-cors-allow-credentials-tag[]
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`http.detailed_errors.enabled`::
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If `true`, enables the output of detailed error messages and stack traces in the response output. Defaults to `true`.
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+
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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.
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`http.pipelining.max_events`::
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The maximum number of events to be queued up in memory before an HTTP connection is closed, defaults to `10000`.
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`http.max_warning_header_count`::
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The maximum number of warning headers in client HTTP responses. Defaults to `unbounded`.
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`http.max_warning_header_size`::
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The maximum total size of warning headers in client HTTP responses. Defaults to `unbounded`.
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[http-rest-request-tracer]
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==== REST request tracer
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The HTTP layer has a dedicated tracer logger which, when activated, logs incoming requests. The log can be dynamically activated
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by setting the level of the `org.elasticsearch.http.HttpTracer` logger to `TRACE`:
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[source,console]
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--------------------------------------------------
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PUT _cluster/settings
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{
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"transient" : {
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"logger.org.elasticsearch.http.HttpTracer" : "TRACE"
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}
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}
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--------------------------------------------------
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You can also control which uris will be traced, using a set of include and exclude wildcard patterns. By default every request will be
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traced.
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[source,console]
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--------------------------------------------------
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PUT _cluster/settings
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{
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"transient" : {
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"http.tracer.include" : "*",
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"http.tracer.exclude" : ""
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}
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}
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--------------------------------------------------
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