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 | 5.x -> master
5.4.3| 5.4.3
5.3.3| 5.3.3
5.2.2| 5.2.2
5.1.2| 5.1.2
1.10.1 | 2.4.1
1.9.5 | 2.3.5
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.download or compile
download pre-build package from here: https://github.com/medcl/elasticsearch-analysis-ik/releases
or compiled from the source:
checkout ik version respective to your elasticsearch version
`git checkout tags/{version}`
`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
```bash
curl -XPUT http://localhost:9200/index
```
2.create a mapping
```bash
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": "text",
"analyzer": "ik_max_word",
"search_analyzer": "ik_max_word",
"include_in_all": "true",
"boost": 8
}
}
}
}'
```
3.index some docs
```bash
curl -XPOST http://localhost:9200/index/fulltext/1 -d'
{"content":"美国留给伊拉克的是个烂摊子吗"}
'
```
```bash
curl -XPOST http://localhost:9200/index/fulltext/2 -d'
{"content":"公安部:各地校车将享最高路权"}
'
```
```bash
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艘中国渔船"}
'
```
```bash
curl -XPOST http://localhost:9200/index/fulltext/4 -d'
{"content":"中国驻洛杉矶领事馆遭亚裔男子枪击 嫌犯已自首"}
'
```
4.query with highlighting
```bash
curl -XPOST http://localhost:9200/index/fulltext/_search -d'
{
"query" : { "match" : { "content" : "中国" }},
"highlight" : {
"pre_tags" : ["", ""],
"post_tags" : ["", ""],
"fields" : {
"content" : {}
}
}
}
'
```
Result
```json
{
"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": "中国驻洛杉矶领事馆遭亚裔男子枪击 嫌犯已自首"
},
"highlight": {
"content": [
"中国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艘中国渔船"
},
"highlight": {
"content": [
"均每天扣1艘中国渔船 "
]
}
}
]
}
}
```
### 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
IK Analyzer 扩展配置
custom/mydict.dic;custom/single_word_low_freq.dic
custom/ext_stopword.dic
location
http://xxx.com/xxx.dic
```
### 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
```xml
location
location
```
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?
```bash
git clone https://github.com/medcl/elasticsearch-analysis-ik
cd elasticsearch-analysis-ik
git checkout tags/{version}
mvn clean
mvn compile
mvn package
```
拷贝和解压release下的文件: #{project_path}/elasticsearch-analysis-ik/target/releases/elasticsearch-analysis-ik-*.zip 到你的 elasticsearch 插件目录, 如: plugins/ik
重启elasticsearch
3.分词测试失败
请在某个索引下调用analyze接口测试,而不是直接调用analyze接口
如:http://localhost:9200/your_index/_analyze?text=中华人民共和国MN&tokenizer=my_ik
Changes
------
*5.0.0*
- 移除名为 `ik` 的analyzer和tokenizer,请分别使用 `ik_smart` 和 `ik_max_word`
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.