126 lines
5.9 KiB
Plaintext
126 lines
5.9 KiB
Plaintext
[[modules-http]]
|
|
== HTTP
|
|
|
|
The http module allows to expose *Elasticsearch* APIs
|
|
over HTTP.
|
|
|
|
The http mechanism is completely asynchronous in nature, meaning that
|
|
there is no blocking thread waiting for a response. The benefit of using
|
|
asynchronous communication for HTTP is solving the
|
|
http://en.wikipedia.org/wiki/C10k_problem[C10k problem].
|
|
|
|
When possible, consider using
|
|
http://en.wikipedia.org/wiki/Keepalive#HTTP_Keepalive[HTTP keep alive]
|
|
when connecting for better performance and try to get your favorite
|
|
client not to do
|
|
http://en.wikipedia.org/wiki/Chunked_transfer_encoding[HTTP chunking].
|
|
|
|
[float]
|
|
=== Settings
|
|
|
|
The settings in the table below can be configured for HTTP. Note that none of
|
|
them are dynamically updatable so for them to take effect they should be set in
|
|
the Elasticsearch <<settings, configuration file>>.
|
|
|
|
[cols="<,<",options="header",]
|
|
|=======================================================================
|
|
|Setting |Description
|
|
|`http.port` |A bind port range. Defaults to `9200-9300`.
|
|
|
|
|`http.publish_port` |The port that HTTP clients should use when
|
|
communicating with this node. Useful when a cluster node is behind a
|
|
proxy or firewall and the `http.port` is not directly addressable
|
|
from the outside. Defaults to the actual port assigned via `http.port`.
|
|
|
|
|`http.bind_host` |The host address to bind the HTTP service to. Defaults to `http.host` (if set) or `network.bind_host`.
|
|
|
|
|`http.publish_host` |The host address to publish for HTTP clients to connect to. Defaults to `http.host` (if set) or `network.publish_host`.
|
|
|
|
|`http.host` |Used to set the `http.bind_host` and the `http.publish_host` Defaults to `http.host` or `network.host`.
|
|
|
|
|`http.max_content_length` |The max content of an HTTP request. Defaults to
|
|
`100mb`.
|
|
|
|
|`http.max_initial_line_length` |The max length of an HTTP URL. Defaults
|
|
to `4kb`
|
|
|
|
|`http.max_header_size` | The max size of allowed headers. Defaults to `8kB`
|
|
|
|
|
|
|`http.compression` |Support for compression when possible (with
|
|
Accept-Encoding). Defaults to `true`.
|
|
|
|
|`http.compression_level` |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` |Enable or disable cross-origin resource sharing,
|
|
i.e. whether a browser on another origin can execute requests against
|
|
Elasticsearch. Set to `true` to enable Elasticsearch to process pre-flight
|
|
https://en.wikipedia.org/wiki/Cross-origin_resource_sharing[CORS] requests.
|
|
Elasticsearch 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 Elasticsearch ignore the `Origin`
|
|
request header, effectively disabling CORS requests because Elasticsearch will
|
|
never respond with the `Access-Control-Allow-Origin` response header. Note that
|
|
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 Elasticsearch, the only way for the client
|
|
to know is to send a pre-flight request and realize the required response headers
|
|
are missing.
|
|
|
|
|`http.cors.allow-origin` |Which origins to allow. Defaults to no origins
|
|
allowed. If you prepend and append a `/` 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. `*` is a valid value but is
|
|
considered a *security risk* as your Elasticsearch instance is open to cross origin
|
|
requests from *anywhere*.
|
|
|
|
|`http.cors.max-age` |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)
|
|
|
|
|`http.cors.allow-methods` |Which methods to allow. Defaults to
|
|
`OPTIONS, HEAD, GET, POST, PUT, DELETE`.
|
|
|
|
|`http.cors.allow-headers` |Which headers to allow. Defaults to
|
|
`X-Requested-With, Content-Type, Content-Length`.
|
|
|
|
|`http.cors.allow-credentials` | Whether the `Access-Control-Allow-Credentials`
|
|
header should be returned. Note: This header is only returned, when the setting is
|
|
set to `true`. Defaults to `false`
|
|
|
|
|`http.detailed_errors.enabled` |Enables or disables the output of detailed error messages
|
|
and stack traces in response output. Note: When set to `false` and the `error_trace` request
|
|
parameter is specified, an error will be returned; when `error_trace` is not specified, a
|
|
simple message will be returned. Defaults to `true`
|
|
|
|
|`http.pipelining` |Enable or disable HTTP pipelining, defaults to `true`.
|
|
|
|
|`http.pipelining.max_events` |The maximum number of events to be queued up in memory before a HTTP connection is closed, defaults to `10000`.
|
|
|
|
|`http.max_warning_header_count` |The maximum number of warning headers in
|
|
client HTTP responses, defaults to unbounded.
|
|
|
|
|`http.max_warning_header_size` |The maximum total size of warning headers in
|
|
client HTTP responses, defaults to unbounded.
|
|
|
|
|=======================================================================
|
|
|
|
It also uses the common
|
|
<<modules-network,network settings>>.
|
|
|
|
[float]
|
|
=== Disable HTTP
|
|
|
|
The http module can be completely disabled and not started by setting
|
|
`http.enabled` to `false`. Elasticsearch nodes (and Java clients) communicate
|
|
internally using the <<modules-transport,transport interface>>, not HTTP. It
|
|
might make sense to disable the `http` layer entirely on nodes which are not
|
|
meant to serve REST requests directly. For instance, you could disable HTTP on
|
|
<<modules-node,data-only nodes>> if you also have
|
|
<<modules-node,client nodes>> which are intended to serve all REST requests.
|
|
Be aware, however, that you will not be able to send any REST requests (eg to
|
|
retrieve node stats) directly to nodes which have HTTP disabled.
|