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前言

最近使用es 6.x版本统计网站访问次数时，提示提示Fielddata is disabled错误

NotSerializableExceptionWrapper[: Fielddata is disabled on text fields by default. Set fielddata=true on [wid] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.]; nested: IllegalArgumentException[Fielddata is disabled on text fields by default. Set fielddata=true on [wid] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.];
 

源代码很简单，根据wid统计访问次数

AggregationBuilder termsBuilder = AggregationBuilders.count("uvCount").field("wid");
SearchRequestBuilder sv = client.prepareSearch(index)
 .setTypes(type)
 .addAggregation(termsBuilder);
SearchResponse response = sv.get();
ValueCount valueCount = response.getAggregations().get("uvCount");
System.out.println(valueCount.getValue());
 

原因分析

应该是5.x后，对排序text类型的时候就会出现上述错误， 聚合这些操作用单独的数据结构(fielddata)缓存到内存里了，需要单独开启。

官方解读 ： Set fielddata=true on [your_field_name]。

解决方案

第一种 开启mapping映射，给wid这个字段的fileddata为true。 但这个方法不推荐，会占用大量内存

PUT wsq_uv_index/_mapping/wsq_uv_type/
{
 "properties":{
 "wid":{
 "type":"text",
 "fielddata":true
 } 
 } 
}
 

第二种 改变查询字段写法，正确姿势：wid.keyword ，问题解决，推荐

AggregationBuilder termsBuilder = AggregationBuilders.count("uvCount").field("wid.keyword");