ElasticSearch修改mapping

参考链接：
http://blog.coinidea.com/elasticsearch-1264.html

用太多的MySQL这样的数据库了，直到有一天，用了ES遇到一个大坑。
就是post mapping的时候有一个“字段”analyzed 和 not_analyzed没区分好，一时失误导致该列所有数据全部分词了。数据量大概1.5亿条。
天真的以为能够像MySQL那样修改一下字段的属性即可。ES是基于Lucene的，没有别的办法，通俗一点讲，要么删除索引，重行导入，要么reindex。所谓的reindex就是建立一个新的index，把旧index的数据拷贝过去。这样的教程网上很多。比如：
http://blog.csdn.net/loveyaqin1990/article/details/77684599
https://www.cnblogs.com/wmx3ng/p/4112993.html

目前网上来讲，具体实现代码很少，我找了好久只找到了Python的实现。本文基于ES官方代码的PHP SDK和bulk有一个迁移实现。

<?php
require 'vendor/autoload.php';
$hosts['hosts'] = array(
    "host"=>'127.0.0.1',
    "port"=>'9200',
    'scheme' => 'http'
);
$client = Elasticsearch\ClientBuilder::create()
            ->setSSLVerification(false)
            ->setHosts($hosts)
            ->build();
for ($i = 1; $i <= 10; $i++) {
    if ($i != 10) { 
        $params['index'] = 'index-0'.$i;        
    }
    else {
        $params['index'] = 'index-'.$i;                 
    }
    echo $params["index"]."\r\n";
    $params['type']  = 'raw';  
    $params['scroll']  = '120s';
    $params["size"] = 50000;
    $params["body"] = array(  
        "query" => array(  
            "match_all" => array()  
        )  
    );
    $response = $client->search($params);
    $step = 1;
    while (isset($response['hits']['hits']) && count($response['hits']['hits']) > 0) {
        echo $step++."\t";
        $scroll_id = $response['_scroll_id']; 
        unset($response);
        $response = $client->scroll(  
            array(  
                "scroll_id" => $scroll_id,
                "scroll" => "120s"
            )  
        ); 
        if (count($response['hits']['hits']) > 0) {  
            $bulk = array('index'=>$params['index']."-reindex",'type'=>$params['type']);
            foreach ($response["hits"]["hits"] as $key=>$val) {
                $bulk['body'][]=array(  
                    'index' => array(  
                            '_id'=>$val['_id']
                        ),  
                );  
                $bulk['body'][] = $val['_source'];
            }
            // insert reindex
            $res = $client->bulk($bulk);
            unset($bulk);
        } else {  
            break;  
        }  
    }   
}           

参考链接：
http://blog.coinidea.com/elasticsearch-1264.html