solr/solr-ref-guide/src/content-streams.adoc

= Content Streams
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Content streams are bulk data passed with a request to Solr.

When Solr RequestHandlers are accessed using path based URLs, the `SolrQueryRequest` object containing the parameters of the request may also contain a list of ContentStreams containing bulk data for the request. (The name SolrQueryRequest is a bit misleading: it is involved in all requests, regardless of whether it is a query request or an update request.)

== Content Stream Sources

Currently request handlers can get content streams in a variety of ways:

* For multipart file uploads, each file is passed as a stream.
* For POST requests where the content-type is not `application/x-www-form-urlencoded`, the raw POST body is passed as a stream. The full POST body is parsed as parameters and included in the Solr parameters.
* The contents of parameter `stream.body` is passed as a stream.
* If remote streaming is enabled and URL content is called for during request handling, the contents of each `stream.url` and `stream.file` parameters are fetched and passed as a stream.

By default, curl sends a `contentType="application/x-www-form-urlencoded"` header. If you need to test a SolrContentHeader content stream, you will need to set the content type with curl's `-H` flag.

== Remote Streaming

Remote streaming lets you send the contents of a URL as a stream to a given Solr RequestHandler. You could use remote streaming to send a remote or local file to an update plugin.

Remote streaming is disabled by default. Enabling it is not recommended in a production situation without additional security between you and untrusted remote clients.

In `solrconfig.xml`, you can enable it by changing the following `enableRemoteStreaming` parameter to `true`:

[source,xml]
----
    *** WARNING ***
    Before enabling remote streaming, you should make sure your
    system has authentication enabled.

    <requestParsers enableRemoteStreaming="false" />
----

When `enableRemoteStreaming` is not specified in `solrconfig.xml`, the default behavior is to _not_ allow remote streaming (i.e., `enableRemoteStreaming="false"`).

Remote streaming can also be enabled through the <<config-api.adoc#,Config API>> as follows:

[.dynamic-tabs]
--
[example.tab-pane#v1setconfigprop]
====
[.tab-label]*V1 API*
[source,bash]
----
curl -H 'Content-type:application/json' -d '{"set-property": {"requestDispatcher.requestParsers.enableRemoteStreaming":true}}' 'http://localhost:8983/solr/techproducts/config'
----
====

[example.tab-pane#v2setconfigprop]
====
[.tab-label]*V2 API*
[source,bash]
----
curl -X POST -H 'Content-type: application/json' -d '{"set-property": {"requestDispatcher.requestParsers.enableRemoteStreaming":true}}' 'http://localhost:8983/api/collections/techproducts/config'
----
====
--

[IMPORTANT]
====
If `enableRemoteStreaming="true"` is used, be aware that this allows _anyone_ to send a request to any URL or local file. If the <<Debugging Requests,DumpRequestHandler>> is enabled, it will allow anyone to view any file on your system.
====

The source of the data can be compressed using gzip, and Solr will generally detect this.
The detection is based on either the presence of a `Content-Encoding: gzip` HTTP header or the file ending with .gz or .gzip.
Gzip doesn't apply to `stream.body`.

== Debugging Requests

The implicit "dump" RequestHandler (see <<implicit-requesthandlers.adoc#,Implicit RequestHandlers>>) simply outputs the contents of the Solr QueryRequest using the specified writer type `wt`. This is a useful tool to help understand what streams are available to the RequestHandlers.