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[[extension-index-elasticsearch,ElasticSearch Index/Query]]
= ElasticSearch Index/Query =


[devstatus]
--------------
source=extensions/indexing-elasticsearch/dev-status.xml
--------------


Index/Query services backed by http://www.elasticsearch.org/[ElasticSearch] search engine built on top of
http://lucene.apache.org/[Apache Lucene].

WARNING: ElasticSearch Index/Query do not support ComplexQueries from the Query API, ie. queries by "example value".

Three modes of operation are supported:

- in-memory ;
- on-filesystem ;
- clustered.

include::../../build/docs/buildinfo/artifact.txt[]

== Embedded: in Memory or on FileSystem ==

Both in-memory and on-filesystem assemblies share the same configuration properties, see below.

=== In Memory Assembly ===

In-memory ElasticSearch Index/Query service relies on the <<library-fileconfig>> to decide where it stores its
transaction logs as there's no in-memory transaction log implementation in ElasticSearch.

Assembly is done using the provided Assembler:

[snippet,java]
----
source=extensions/indexing-elasticsearch/src/test/java/org/apache/zest/index/elasticsearch/DocumentationSupport.java
tag=memory
----


=== On FileSystem Assembly ===

Filesystem based ElasticSearch Index/Query service relies on the <<library-fileconfig>> to decide where it stores its
index data, transaction logs etc...

Assembly is done using the provided Assembler:

[snippet,java]
----
source=extensions/indexing-elasticsearch/src/test/java/org/apache/zest/index/elasticsearch/DocumentationSupport.java
tag=filesystem
----

=== Configuration ===

IMPORTANT: By default queries can only traverse Aggregated Associations, if you want to be able to traverse all
Associations set the `indexNonAggregatedAssociations` configuration property to `TRUE`.

Here are the configuration properties for both the in-memory and on-filesystem ElasticSearch Index/Query services:

[snippet,java]
----
source=extensions/indexing-elasticsearch/src/main/java/org/apache/zest/index/elasticsearch/ElasticSearchConfiguration.java
tag=config
----

All configuration properties are defaulted meaning that you can use ElasticSearch Index/Query service without
configuration.

== In an ElasticSearch cluster ==

=== Assembly ===

Assembly is done using the provided Assembler:

[snippet,java]
----
source=extensions/indexing-elasticsearch/src/test/java/org/apache/zest/index/elasticsearch/DocumentationSupport.java
tag=cluster
----


=== Configuration ===

Here are the configuration properties for the clustered ElasticSearch Index/Query service. Note that it inherits the
properties defined in the in-memory or on-filesystem configuration, see above.

[snippet,java]
----
source=extensions/indexing-elasticsearch/src/main/java/org/apache/zest/index/elasticsearch/ElasticSearchClusterConfiguration.java
tag=config
----

Again, all configuration properties are defaulted meaning that you can use ElasticSearch Index/Query service without
configuration.