/elasticsearch-analysis-ik

The IK Analysis plugin integrates Lucene IK analyzer into elasticsearch, support customized dictionary.

Primary LanguageJavaApache License 2.0Apache-2.0

IK Analysis for Elasticsearch

The IK Analysis plugin integrates Lucene IK analyzer (http://code.google.com/p/ik-analyzer/) into elasticsearch, support customized dictionary.

Analyzer: ik_smart , ik_max_word , Tokenizer: ik_smart , ik_max_word

Versions

IK version ES version
master 2.3.1 -> master
1.9.3 2.3.3
1.9.0 2.3.0
1.8.1 2.2.1
1.7.0 2.1.1
1.5.0 2.0.0
1.2.6 1.0.0
1.2.5 0.90.x
1.1.3 0.20.x
1.0.0 0.16.2 -> 0.19.0

Install

1.compile

mvn package

copy and unzip target/releases/elasticsearch-analysis-ik-{version}.zip to your-es-root/plugins/ik

2.restart elasticsearch

Tips:

ik_max_word: 会将文本做最细粒度的拆分,比如会将“中华人民共和国国歌”拆分为“中华人民共和国,中华人民,中华,华人,人民共和国,人民,人,民,共和国,共和,和,国国,国歌”,会穷尽各种可能的组合;

ik_smart: 会做最粗粒度的拆分,比如会将“中华人民共和国国歌”拆分为“中华人民共和国,国歌”。

Quick Example

1.create a index

curl -XPUT http://localhost:9200/index

2.create a mapping

curl -XPOST http://localhost:9200/index/fulltext/_mapping -d'
{
    "fulltext": {
             "_all": {
            "analyzer": "ik_max_word",
            "search_analyzer": "ik_max_word",
            "term_vector": "no",
            "store": "false"
        },
        "properties": {
            "content": {
                "type": "string",
                "store": "no",
                "term_vector": "with_positions_offsets",
                "analyzer": "ik_max_word",
                "search_analyzer": "ik_max_word",
                "include_in_all": "true",
                "boost": 8
            }
        }
    }
}'

3.index some docs

curl -XPOST http://localhost:9200/index/fulltext/1 -d'
{"content":"美国留给伊拉克的是个烂摊子吗"}
'
curl -XPOST http://localhost:9200/index/fulltext/2 -d'
{"content":"公安部:各地校车将享最高路权"}
'
curl -XPOST http://localhost:9200/index/fulltext/3 -d'
{"content":"中韩渔警冲突调查:韩警平均每天扣1艘**渔船"}
'
curl -XPOST http://localhost:9200/index/fulltext/4 -d'
{"content":"**驻洛杉矶领事馆遭亚裔男子枪击 嫌犯已自首"}
'

4.query with highlighting

curl -XPOST http://localhost:9200/index/fulltext/_search  -d'
{
    "query" : { "term" : { "content" : "**" }},
    "highlight" : {
        "pre_tags" : ["<tag1>", "<tag2>"],
        "post_tags" : ["</tag1>", "</tag2>"],
        "fields" : {
            "content" : {}
        }
    }
}
'

Result

{
    "took": 14,
    "timed_out": false,
    "_shards": {
        "total": 5,
        "successful": 5,
        "failed": 0
    },
    "hits": {
        "total": 2,
        "max_score": 2,
        "hits": [
            {
                "_index": "index",
                "_type": "fulltext",
                "_id": "4",
                "_score": 2,
                "_source": {
                    "content": "**驻洛杉矶领事馆遭亚裔男子枪击 嫌犯已自首"
                },
                "highlight": {
                    "content": [
                        "<tag1>**</tag1>驻洛杉矶领事馆遭亚裔男子枪击 嫌犯已自首 "
                    ]
                }
            },
            {
                "_index": "index",
                "_type": "fulltext",
                "_id": "3",
                "_score": 2,
                "_source": {
                    "content": "中韩渔警冲突调查:韩警平均每天扣1艘**渔船"
                },
                "highlight": {
                    "content": [
                        "均每天扣1艘<tag1>**</tag1>渔船 "
                    ]
                }
            }
        ]
    }
}

Dictionary Configuration

IKAnalyzer.cfg.xml can be located at {conf}/analysis-ik/config/IKAnalyzer.cfg.xml or {plugins}/elasticsearch-analysis-ik-*/config/IKAnalyzer.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
	<comment>IK Analyzer 扩展配置</comment>
	<!--用户可以在这里配置自己的扩展字典 -->
	<entry key="ext_dict">custom/mydict.dic;custom/single_word_low_freq.dic</entry>
	 <!--用户可以在这里配置自己的扩展停止词字典-->
	<entry key="ext_stopwords">custom/ext_stopword.dic</entry>
 	<!--用户可以在这里配置远程扩展字典 -->
	<entry key="remote_ext_dict">location</entry>
 	<!--用户可以在这里配置远程扩展停止词字典-->
	<entry key="remote_ext_stopwords">http://xxx.com/xxx.dic</entry>
</properties>

热更新 IK 分词使用方法

目前该插件支持热更新 IK 分词,通过上文在 IK 配置文件中提到的如下配置

 	<!--用户可以在这里配置远程扩展字典 -->
	<entry key="remote_ext_dict">location</entry>
 	<!--用户可以在这里配置远程扩展停止词字典-->
	<entry key="remote_ext_stopwords">location</entry>

其中 location 是指一个 url,比如 http://yoursite.com/getCustomDict,该请求只需满足以下两点即可完成分词热更新。

  1. 该 http 请求需要返回两个头部(header),一个是 Last-Modified,一个是 ETag,这两者都是字符串类型,只要有一个发生变化,该插件就会去抓取新的分词进而更新词库。

  2. 该 http 请求返回的内容格式是一行一个分词,换行符用 \n 即可。

满足上面两点要求就可以实现热更新分词了,不需要重启 ES 实例。

可以将需自动更新的热词放在一个 UTF-8 编码的 .txt 文件里,放在 nginx 或其他简易 http server 下,当 .txt 文件修改时,http server 会在客户端请求该文件时自动返回相应的 Last-Modified 和 ETag。可以另外做一个工具来从业务系统提取相关词汇,并更新这个 .txt 文件。

have fun.

常见问题

1.自定义词典为什么没有生效?

请确保你的扩展词典的文本格式为 UTF8 编码

2.如何手动安装?

git clone https://github.com/medcl/elasticsearch-analysis-ik
cd elasticsearch-analysis-ik
mvn clean
mvn compile
mvn package

copy & unzip file #{project_path}/elasticsearch-analysis-ik/target/releases/elasticsearch-analysis-ik-*.zip to your elasticsearch's folder: plugins/ik

Thanks

YourKit supports IK Analysis for ElasticSearch project with its full-featured Java Profiler. YourKit, LLC is the creator of innovative and intelligent tools for profiling Java and .NET applications. Take a look at YourKit's leading software products: YourKit Java Profiler and YourKit .NET Profiler.