ElasticSearch修改mapping

參考連接： http://blog.coinidea.com/elasticsearch-1264.html

用太多的MySQL這樣的數據庫了，直到有一天，用了ES遇到一個大坑。 就是post mapping的時候有一個「字段」analyzed 和 not_analyzed沒區分好，一時失誤致使該列全部數據所有分詞了。數據量大概1.5億條。 天真的覺得可以像MySQL那樣修改一下字段的屬性便可。ES是基於Lucene的，沒有別的辦法，通俗一點講，要麼刪除索引，重行導入，要麼reindex。所謂的reindex就是創建一個新的index，把舊index的數據拷貝過去。這樣的教程網上不少。好比： http://blog.csdn.net/loveyaqin1990/article/details/77684599 https://www.cnblogs.com/wmx3ng/p/4112993.html

目前網上來說，具體實現代碼不多，我找了很久只找到了Python的實現。本文基於ES官方代碼的PHP SDK和bulk有一個遷移實現。

<?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;  
        }  
    }   
}

參考連接： http://blog.coinidea.com/elasticsearch-1264.html