在es的使用过程中，全文搜索属于一个常见的场景，特别是当我们将es作为日志存储检索来使用时，根据关键字查询对应的日志信息，可以怎么处理呢?
1. 动态模板结合copy_to方式
在创建索引的时候，我们新增一个allColumnValue的字段，将所有其他的column值都拷贝过去，然后针对这个字段进行检索，即可以实现全文的搜索方式了
这里借助dynamic_templtes来实现上面的自动拷贝逻辑，因此我们可以如下创建一个索引
PUT search_all_demo { "mappings": { "dynamic_templates" : [ { "copy_to_allcolumnvalue" : { "match_mapping_type" : "*", "mapping" : { "copy_to" : "allColumnValue", "ignore_above" : 512, "type" : "keyword" } } } ], "properties": { "allColumnValue" : { "type" : "text" } } } } 复制代码
创建上面的映射表时，两个点
- allColumnValue：字段
- dynamic_templates: 实现字段拷贝
接下来写入一个数据进行测试
POST search_all_demo/_doc { "name": "一灰灰", "site": "www.hhui.top", "title": "java developer" } 复制代码
然后检索一下是否可以查询到希望的结果
GET search_all_demo/_search { "query": { "match": { "allColumnValue": "灰灰" } } } 复制代码
上面这个查询之后，正常会命中我们的数据，并返回
{ "took" : 1, "timed_out" : false, "_shards" : { "total" : 1, "successful" : 1, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : { "value" : 1, "relation" : "eq" }, "max_score" : 0.7911257, "hits" : [ { "_index" : "search_all_demo", "_type" : "_doc", "_id" : "1FoBk3wB-kdeh8MF_IbL", "_score" : 0.7911257, "_source" : { "name" : "一灰灰", "site" : "www.hhui.top", "title" : "java developer" } } ] } } 复制代码
注意
使用上面这种配置时，对于Field有要求，当我们制定一个Map类型时，会失败
POST search_all_demo/_doc { "name": "一灰", "site": "blog.hhui.top", "ddd": { "user": "yihui", "pwd": "yihui" } } 复制代码
上面的ddd会提示异常
{ "error" : { "root_cause" : [ { "type" : "mapper_parsing_exception", "reason" : "failed to parse field [ddd] of type [keyword] in document with id '11qek3wB-kdeh8MFm4bN'. Preview of field's value: '{pwd=yihui, user=yihui}'" } ], "type" : "mapper_parsing_exception", "reason" : "failed to parse field [ddd] of type [keyword] in document with id '11qek3wB-kdeh8MFm4bN'. Preview of field's value: '{pwd=yihui, user=yihui}'", "caused_by" : { "type" : "illegal_state_exception", "reason" : "Can't get text on a START_OBJECT at 4:10" } }, "status" : 400 } 复制代码
2. 部分字段组合搜索
上面介绍的是全量的数据凭借到allColumnValue，从而实现全文检索；可能在实际的场景中，我只是希望对部分的field进行联合检索，基于此可以如下设置
PUT search_union_demo { "mappings": { "properties": { "allColumnValue" : { "type" : "text" }, "name": { "type" : "keyword", "ignore_above" : 512, "copy_to" : [ "allColumnValue" ] }, "site" : { "type" : "keyword", "ignore_above" : 512, "copy_to" : [ "allColumnValue" ] } } } } 复制代码
新增两个数据
POST search_union_demo/_doc { "name": "test", "site": "spring.hhui.top", "ddd": { "user": "一灰", "pwd": "yihui" } } POST search_union_demo/_doc { "name": "一灰", "site": "blog.hhui.top", "ddd": { "user": "yihui", "pwd": "yihui" } } 复制代码
然后我们检索一灰时，可以查到第二条数据
GET search_union_demo/_search { "query": { "match": { "allColumnValue": "一灰" } } } 复制代码
输出结果
{ "took" : 2, "timed_out" : false, "_shards" : { "total" : 1, "successful" : 1, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : { "value" : 1, "relation" : "eq" }, "max_score" : 1.2814486, "hits" : [ { "_index" : "search_union_demo", "_type" : "_doc", "_id" : "2Fqjk3wB-kdeh8MFy4aC", "_score" : 1.2814486, "_source" : { "name" : "一灰", "site" : "blog.hhui.top", "ddd" : { "user" : "yihui", "pwd" : "yihui" } } } ] } } 复制代码
3. 小结
本文主要介绍借助copy_to，来实现es的联合/全文搜索的功能；通过简单的设置，来支撑更友好的查询场景
