80 lines
3.8 KiB
Markdown
80 lines
3.8 KiB
Markdown
Mapper Attachments Type for ElasticSearch
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==================================
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The mapper attachments plugin adds the `attachment` type to ElasticSearch using Tika.
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In order to install the plugin, simply run: `bin/plugin -install elasticsearch/elasticsearch-mapper-attachments/1.2.0`.
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| Attachment Mapper Plugin | ElasticSearch |
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| master | 0.19 -> master |
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| 1.2.0 | 0.19 -> master |
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| 1.1.0 | 0.19 -> master |
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| 1.0.0 | 0.18 |
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The `attachment` type allows to index different "attachment" type field (encoded as `base64`), for example, microsoft office formats, open document formats, ePub, HTML, and so on (full list can be found [here](http://lucene.apache.org/tika/0.10/formats.html)).
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The `attachment` type is provided as a plugin extension. The plugin is a simple zip file that can be downloaded and placed under `$ES_HOME/plugins` location. It will be automatically detected and the `attachment` type will be added.
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Using the attachment type is simple, in your mapping JSON, simply set a certain JSON element as attachment, for example:
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{
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"person" : {
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"properties" : {
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"my_attachment" : { "type" : "attachment" }
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}
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}
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}
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In this case, the JSON to index can be:
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{
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"my_attachment" : "... base64 encoded attachment ..."
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}
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Or it is possible to use more elaborated JSON if content type or resource name need to be set explicitly:
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{
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"my_attachment" : {
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"_content_type" : "application/pdf",
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"_name" : "resource/name/of/my.pdf",
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"content" : "... base64 encoded attachment ..."
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}
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}
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The `attachment` type not only indexes the content of the doc, but also automatically adds meta data on the attachment as well (when available). The metadata supported are: `date`, `title`, `author`, and `keywords`. They can be queried using the "dot notation", for example: `my_attachment.author`.
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Both the meta data and the actual content are simple core type mappers (string, date, ...), thus, they can be controlled in the mappings. For example:
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{
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"person" : {
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"properties" : {
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"file" : {
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"type" : "attachment",
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"fields" : {
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"file" : {"index" : "no"},
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"date" : {"store" : "yes"},
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"author" : {"analyzer" : "myAnalyzer"}
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}
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}
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}
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}
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}
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In the above example, the actual content indexed is mapped under `fields` name `file`, and we decide not to index it, so it will only be available in the `_all` field. The other fields map to their respective metadata names, but there is no need to specify the `type` (like `string` or `date`) since it is already known.
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Indexed Characters
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------------------
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By default, `100000` characters are extracted when indexing the content. This default value can be changed by setting the `index.mapping.attachment.indexed_chars` setting. It can also be provided on a per document indexed using the `_indexed_chars` parameter. `-1` can be set to extract all text, but note that all the text needs to be allowed to be represented in memory.
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Note, this feature is support since `1.3.0` version.
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The plugin uses [Apache Tika](http://lucene.apache.org/tika/) to parse attachments, so many formats are supported, listed [here](http://lucene.apache.org/tika/0.10/formats.html).
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