mirror of
https://github.com/honeymoose/OpenSearch.git
synced 2025-02-06 04:58:50 +00:00
9822a6f911
It looks like we weren't clear on when and why you should close the high level client and folks were closing it after every request which is not efficient. This explains why you should close the client and when so this shouldn't be as common. Closes #32001
156 lines
6.5 KiB
Plaintext
156 lines
6.5 KiB
Plaintext
[[java-rest-high-getting-started]]
|
|
== Getting started
|
|
|
|
This section describes how to get started with the high-level REST client from
|
|
getting the artifact to using it in an application.
|
|
|
|
[[java-rest-high-compatibility]]
|
|
=== Compatibility
|
|
The Java High Level REST Client requires Java 1.8 and depends on the Elasticsearch
|
|
core project. The client version is the same as the Elasticsearch version that the
|
|
client was developed for. It accepts the same request arguments as the `TransportClient`
|
|
and returns the same response objects. See the <<java-rest-high-level-migration>>
|
|
if you need to migrate an application from `TransportClient` to the new REST client.
|
|
|
|
The High Level Client is guaranteed to be able to communicate with any Elasticsearch
|
|
node running on the same major version and greater or equal minor version. It
|
|
doesn't need to be in the same minor version as the Elasticsearch nodes it
|
|
communicates with, as it is forward compatible meaning that it supports
|
|
communicating with later versions of Elasticsearch than the one it was developed for.
|
|
|
|
The 6.0 client is able to communicate with any 6.x Elasticsearch node, while the 6.1
|
|
client is for sure able to communicate with 6.1, 6.2 and any later 6.x version, but
|
|
there may be incompatibility issues when communicating with a previous Elasticsearch
|
|
node version, for instance between 6.1 and 6.0, in case the 6.1 client supports new
|
|
request body fields for some APIs that are not known by the 6.0 node(s).
|
|
|
|
It is recommended to upgrade the High Level Client when upgrading the Elasticsearch
|
|
cluster to a new major version, as REST API breaking changes may cause unexpected
|
|
results depending on the node that is hit by the request, and newly added APIs will
|
|
only be supported by the newer version of the client. The client should always be
|
|
updated last, once all of the nodes in the cluster have been upgraded to the new
|
|
major version.
|
|
|
|
[[java-rest-high-javadoc]]
|
|
=== Javadoc
|
|
|
|
The javadoc for the REST high level client can be found at {rest-high-level-client-javadoc}/index.html.
|
|
|
|
[[java-rest-high-getting-started-maven]]
|
|
=== Maven Repository
|
|
|
|
The high-level Java REST client is hosted on
|
|
http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22org.elasticsearch.client%22[Maven
|
|
Central]. The minimum Java version required is `1.8`.
|
|
|
|
The High Level REST Client is subject to the same release cycle as
|
|
Elasticsearch. Replace the version with the desired client version.
|
|
|
|
If you are looking for a SNAPSHOT version, the Elastic Maven Snapshot repository is available
|
|
at https://snapshots.elastic.co/maven/.
|
|
|
|
[[java-rest-high-getting-started-maven-maven]]
|
|
==== Maven configuration
|
|
|
|
Here is how you can configure the dependency using maven as a dependency manager.
|
|
Add the following to your `pom.xml` file:
|
|
|
|
["source","xml",subs="attributes"]
|
|
--------------------------------------------------
|
|
<dependency>
|
|
<groupId>org.elasticsearch.client</groupId>
|
|
<artifactId>elasticsearch-rest-high-level-client</artifactId>
|
|
<version>{version}</version>
|
|
</dependency>
|
|
--------------------------------------------------
|
|
|
|
[[java-rest-high-getting-started-maven-gradle]]
|
|
==== Gradle configuration
|
|
|
|
Here is how you can configure the dependency using gradle as a dependency manager.
|
|
Add the following to your `build.gradle` file:
|
|
|
|
["source","groovy",subs="attributes"]
|
|
--------------------------------------------------
|
|
dependencies {
|
|
compile 'org.elasticsearch.client:elasticsearch-rest-high-level-client:{version}'
|
|
}
|
|
--------------------------------------------------
|
|
|
|
[[java-rest-high-getting-started-maven-lucene]]
|
|
==== Lucene Snapshot repository
|
|
|
|
The very first releases of any major version (like a beta), might have been built on top of a Lucene Snapshot version.
|
|
In such a case you will be unable to resolve the Lucene dependencies of the client.
|
|
|
|
For example, if you want to use the `6.0.0-beta1` version which depends on Lucene `7.0.0-snapshot-00142c9`, you must
|
|
define the following repository.
|
|
|
|
For Maven:
|
|
|
|
["source","xml",subs="attributes"]
|
|
--------------------------------------------------
|
|
<repository>
|
|
<id>elastic-lucene-snapshots</id>
|
|
<name>Elastic Lucene Snapshots</name>
|
|
<url>http://s3.amazonaws.com/download.elasticsearch.org/lucenesnapshots/00142c9</url>
|
|
<releases><enabled>true</enabled></releases>
|
|
<snapshots><enabled>false</enabled></snapshots>
|
|
</repository>
|
|
--------------------------------------------------
|
|
|
|
For Gradle:
|
|
|
|
["source","groovy",subs="attributes"]
|
|
--------------------------------------------------
|
|
maven {
|
|
url 'http://s3.amazonaws.com/download.elasticsearch.org/lucenesnapshots/00142c9'
|
|
}
|
|
--------------------------------------------------
|
|
|
|
[[java-rest-high-getting-started-dependencies]]
|
|
=== Dependencies
|
|
|
|
The High Level Java REST Client depends on the following artifacts and their
|
|
transitive dependencies:
|
|
|
|
- org.elasticsearch.client:elasticsearch-rest-client
|
|
- org.elasticsearch:elasticsearch
|
|
|
|
|
|
[[java-rest-high-getting-started-initialization]]
|
|
=== Initialization
|
|
|
|
A `RestHighLevelClient` instance needs a <<java-rest-low-usage-initialization,REST low-level client builder>>
|
|
to be built as follows:
|
|
|
|
["source","java",subs="attributes,callouts,macros"]
|
|
--------------------------------------------------
|
|
include-tagged::{doc-tests}/MiscellaneousDocumentationIT.java[rest-high-level-client-init]
|
|
--------------------------------------------------
|
|
|
|
The high-level client will internally create the low-level client used to
|
|
perform requests based on the provided builder. That low-level client
|
|
maintains a pool of connections and starts some threads so you should
|
|
close the high-level client when you are well and truly done with
|
|
it and it will in turn close the internal low-level client to free those
|
|
resources. This can be done through the `close`:
|
|
|
|
["source","java",subs="attributes,callouts,macros"]
|
|
--------------------------------------------------
|
|
include-tagged::{doc-tests}/MiscellaneousDocumentationIT.java[rest-high-level-client-close]
|
|
--------------------------------------------------
|
|
|
|
In the rest of this documentation about the Java High Level Client, the `RestHighLevelClient` instance
|
|
will be referenced as `client`.
|
|
|
|
[[java-rest-hight-getting-started-request-options]]
|
|
=== RequestOptions
|
|
|
|
All APIs in the `RestHighLevelClient` accept a `RequestOptions` which you can
|
|
use to customize the request in ways that won't change how Elasticsearch
|
|
executes the request. For example, this is the place where you'd specify a
|
|
`NodeSelector` to control which node receives the request. See the
|
|
<<java-rest-low-usage-request-options,low level client documentation>> for
|
|
more examples of customizing the options.
|