elasticsearch初探

https://github.com/richardwilly98/elasticsearch-river-mongodb

https://github.com/mallocator/Elasticsearch-MySQL-River

 https://github.com/BioMedCentralLtd/spring-data-elasticsearch-sample-application/blob/master/src/test/resources/springContext-book-test.xml 实例

http://www.elasticsearch.org/guide/en/elasticsearch/client/java-api/current/search.html

http://docs.spring.io/spring-data/elasticsearch/docs/current/reference/html/#repositories.create-instances.spring

为了替换现在使用体验比较差的SegmentFault搜索，我开始了前期搜索引擎的探索。目前首选是elasticsearch

elasticsearch需要java环境
安装java

sudo aptitude install openjdk-7-jre

下载elasticsearch
http://www.elasticsearch.org/overview/elkdownloads/
https://download.elasticsearch.org/elasticsearch/elasticsearch/elasticsearch-1.1.0.deb

安装
因为我的环境是ubuntu，所以直接用它的deb包。

sudo dpkg -i elasticsearch-1.1.0.deb

启动

sudo /etc/init.d/elasticsearch start

jdbc river
用于定期或者实时导入需要搜索的数据
我们数据库是mysql，所以用的官方elasticsearch-river-jdbc
https://github.com/jprante/elasticsearch-river-jdbc

river jdbc quickstart
https://github.com/jprante/elasticsearch-river-jdbc/wiki/Quickstart

安装

cd /usr/share/elasticsearch
sudo /bin/plugin --install river-jdbc --url http://bit.ly/1jyXrR9

如果安装失败，可以手动下载后再安装。

sudo /bin/plugin --install river-jdbc --url file:///tmp/elasticsearch-river-jdbc-1.0.0.1.zip

创建一个JDBC river

curl -XPUT 'localhost:9200/_river/my_jdbc_river/_meta' -d '{
    "type" : "jdbc",
    "jdbc" : {
        "url" : "jdbc:mysql://localhost:3306/test",
        "user" : "root",
        "password" : "",
        "sql" : "select * from question",
        "index" : "question",
        "type" : "question"
    }
}'

测试导入效果：

curl -XGET 'localhost:9200/question/_search?pretty&q=*'

or

localhost:9200/question/_search?pretty&q=*

官方有中文分词支持，但是不是非常准确，这里使用medcl的ik分词
安装elasticsearch-analysis-ik

cd /tmp
wget https://github.com/medcl/elasticsearch-analysis-ik/archive/master.zip
unzip master.zip
cd elasticsearch-analysis-ik/

这里需要用mvn package命令打包成elasticsearch-analysis-ik-1.2.6.jar

mvn package

没有maven的可以安装一下

sudo aptitude install maven

复制elasticsearch-analysis-ik-1.2.6.jar到ES_HOME/plugins/analysis-ik下

sudo cp elasticsearch-analysis-ik-1.2.6.jar /usr/share/elasticsearch/plugins/analysis-ik

将ik的配置和字典都复制到ES_HOME/config下

sudo cp -R ik /etc/elasticsearch

elasticsearch配置启用ik

sudo vim /etc/elasticsearch

底部增加一行

index.analysis.analyzer.ik.type : 'ik'

重启服务加载配置

sudo service elasticsearch restart

测试分词效果

localhost:9200/question/_analyze?analyzer=ik&pretty=true&text=杭州堆栈科技有限公司

返回

{
  "tokens" : [ {
    "token" : "杭州",
    "start_offset" : 0,
    "end_offset" : 2,
    "type" : "CN_WORD",
    "position" : 1
  }, {
    "token" : "堆栈",
    "start_offset" : 2,
    "end_offset" : 4,
    "type" : "CN_WORD",
    "position" : 2
  }, {
    "token" : "科技",
    "start_offset" : 4,
    "end_offset" : 6,
    "type" : "CN_WORD",
    "position" : 3
  }, {
    "token" : "有限公司",
    "start_offset" : 6,
    "end_offset" : 10,
    "type" : "CN_WORD",
    "position" : 4
  } ]
}

测试官方的php客户端
官方的php客户端通过composer安装
先安装composer

curl -s http://getcomposer.org/installer | php
sudo mv composer.phar /usr/bin/composer

生成一个composer.json，写入

{
    "require": {
        "elasticsearch/elasticsearch": "~1.0"
    }
}

开始安装

composer install --no-dev

项目中require之后就可以使用了

<?php
require 'vendor/autoload.php';

$client = new Elasticsearch\Client();

使用中文分词ik的mapping

$params['index'] = 'question';
$params['type']  = 'question';    
$myTypeMapping = array(
        '_source' => array(
            'enabled' => true
        ),
        '_all' => array(
            'indexAnalyzer'  => 'ik',
            'searchAnalyzer' => 'ik',
            'term_vector'    => 'no',
            'store'          => 'false'
        ),
        'properties' => array(
            'text' => array(
                'type' => 'string',
                'term_vector' => 'with_positions_offsets',
                'indexAnalyzer' => 'ik',
                'searchAnalyzer' => 'ik',
                'include_in_all' => 'true',
                'boost' => 8
            ),
            'title' => array(
                'type' => 'string',
                'term_vector' => 'with_positions_offsets',
                'indexAnalyzer' => 'ik',
                'searchAnalyzer' => 'ik',
                'include_in_all' => 'true',
                'boost' => 8
            )
        )
    );
$params['body']['question'] = $myTypeMapping;
$response = $client->indices()->putMapping($params);

测试一下效果，搜索问题内容‘php框架’

$searchParams = array();
$searchParams['index'] = 'question';
$searchParams['type']  = 'question';
$searchParams['body']['query']['match']['text'] = 'php框架';

返回，取了几条

1. segmentfault是用什么php框架写的啊？ http://segmentfault.com/q/1010000000095152
2. 刚学PHP，求介绍THINKPHP框架的优劣 http://segmentfault.com/q/1010000000129535
3. symfony是不是比其他的php框架功能强大很多？
   http://segmentfault.com/q/1010000000095952
4. python 框架繁多，如何整体把握？ http://segmentfault.com/q/1010000000186319
5. 什么是ORM，以及在php上的使用？ http://segmentfault.com/q/1010000000318125
6. codeigniter框架php依赖安装问题 http://segmentfault.com/q/1010000000253966

总结
elasticsearch安装和使用还是非常简单的，从没有优化的返回结果来看也比现有的搜索要理想。
不过唯一的缺点就是文档相比solr还是太少，很多都只给了最基本的例子。
优化 组合搜索等等，都要自己琢磨和查找。