es 为索引添加别名 es索引别名的使用场景

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mob64ca1409970a 2024-05-21 11:40:45

文章标签 es 为索引添加别名 elasticsearch 搜索引擎搜索高亮 文章分类 架构后端开发

es之索引别名的使用

别名有什么用？

在开发中，随着业务需求的迭代，较老的业务逻辑就要面临更新甚至是重构，而对于es来说，为了适应新的业务逻辑，可能就要对原有的索引做一些修改，比如对某些字段做调整，甚至是重建索引。而做这些操作的时候，可能会对业务造成影响，甚至是停机调整等问题。由此，es提供了索引别名来解决这些问题。 索引别名就像一个快捷方式或是软连接，可以指向一个或多个索引，也可以给任意一个需要索引名的API来使用。别名的应用为程序提供了极大地灵活性

查询别名

GET /nba/_alias
GET /_alias

新增别名

POST /_aliases
{
"actions": [
{
"add": {
"index": "nba",
"alias": "nba_v1.0"
}
}
]
}
PUT /nba/_alias/nba_v1.1

删除别名

POST /_aliases
{
"actions": [
{
"remove": {
"index": "nba",
"alias": "nba_v1.0"
}
}
]
}
DELETE /nba/_alias/nba_v1.1

重命名

POST /_aliases
{
"actions": [
{
"remove": {
"index": "nba",
"alias": "nba_v1.0"
}
},
{
"add": {
"index": "nba",
"alias": "nba_v2.0"
}
}
]
}

为多个索引指定一个别名

POST /_aliases
{
"actions": [
{
"add": {
"index": "nba",
"alias": "national_player"
}
},
{
"add": {
"index": "wnba",
"alias": "national_player"
}
}
]
}

为同个索引指定多个别名

POST /_aliases
{
"actions": [
{
"add": {
"index": "nba",
"alias": "nba_v2.1"
}
},
{
"add": {
"index": "nba",
"alias": "nba_v2.2"
}
}
]
}

通过别名读索引

当别名指定了一个索引，则查出一个索引

GET /nba_v2.1

当别名指定了了多个索引，则查出多个索引

GET /national_player

通过别名写索引

当别名指定了一个索引，则可以做写的操作

POST /nba_v2.1/_doc/566
{
"countryEn": "Croatia",
"teamName": "快船",
"birthDay": 858661200000,
"country": "克罗地亚",
"teamCityEn": "LA",
"code": "ivica_zubac",
"displayAffiliation": "Croatia",
"displayName": "伊维察祖巴茨哥哥",
"schoolType": "",
"teamConference": "⻄西部",
"teamConferenceEn": "Western",
"weight": "108.9 公⽄斤",
"teamCity": "洛洛杉矶",
"playYear": 3,
"jerseyNo": "40",
"teamNameEn": "Clippers",
"draft": 2016,
"displayNameEn": "Ivica Zubac",
"heightValue": 2.16,
"birthDayStr": "1997-03-18",
"position": "中锋",
"age": 22,
"playerId": "1627826"
}

当别名指定了多个索引，可以指定写某个索引 "is_write_index": true

POST /_aliases
{
"actions": [
{
"add": {
"index": "nba",
"alias": "national_player",
"is_write_index": true
}
},
{
"add": {
"index": "wnba",
"alias": "national_player"
}
}
]
}
POST /national_player/_doc/566
{
"countryEn": "Croatia",
"teamName": "快船",
"birthDay": 858661200000,
"country": "克罗地亚",
"teamCityEn": "LA",
"code": "ivica_zubac",
"displayAffiliation": "Croatia",
"displayName": "伊维察祖巴茨妹妹",
"schoolType": "",
"teamConference": "⻄西部",
"teamConferenceEn": "Western",
"weight": "108.9 公⽄斤",
"teamCity": "洛洛杉矶",
"playYear": 3,
"jerseyNo": "40",
"teamNameEn": "Clippers",
"draft": 2016,
"displayNameEn": "Ivica Zubac",
"heightValue": 2.16,
"birthDayStr": "1997-03-18",
"position": "中锋",
"age": 22,
"playerId": "1627826"
}

es之如何重建索引

背景

Elasticsearch是一个实时的分布式搜索引擎，为用户提供搜索服务，当我们决定存储某种数据时，在创建索引的时候需要将数据结构完整确定下来，于此同时索引的设定和很多固定配置将不能改变。当需要改变数据结构时，就需要重新建立索引，为此，Elastic团队提供了很多辅助工具帮助开发人员进行重建索引

步骤

nba取一个别名nba_latest, nba_latest作为对外使用
新增一个索引nba_20220101，结构复制于nba索引，根据业务要求修改字段
将nba数据同步到nba_20220101
给nba_20220101添加别名nba_latest，删除nba别名nba_latest
删除nba索引

对外提供访问nba索引时使用的是nba_latest别名

新增一个索引(比如修改字段类型，jerseyNo改成keyword类型)

PUT /nba_20220101
{
"mappings": {
"properties": {
"age": {
"type": "integer"
},
"birthDay": {
"type": "date"
},
"birthDayStr": {
"type": "keyword"
},
"code": {
"type": "text"
},
"country": {
"type": "keyword"
},
"countryEn": {
"type": "keyword"
},
"displayAffiliation": {
"type": "text"
},
"displayName": {
"type": "text"
},
"displayNameEn": {
"type": "text"
},
"draft": {
"type": "long"
},
"heightValue": {
"type": "float"
},
"jerseyNo": {
"type": "keyword"
},
"playYear": {
"type": "long"
},
"playerId": {
"type": "keyword"
},
"position": {
"type": "text"
},
"schoolType": {
"type": "text"
},
"teamCity": {
"type": "text"
},
"teamCityEn": {
"type": "text"
},
"teamConference": {
"type": "keyword"
},
"teamConferenceEn": {
"type": "keyword"
},
"teamName": {
"type": "keyword"
},
"teamNameEn": {
"type": "keyword"
},
"weight": {
"type": "text"
}
}
}
}

将旧索引数据copy到新索引

同步等待，接口将会在 reindex 结束后返回

POST /_reindex
{
"source": {
"index": "nba"
},
"dest": {
"index": "nba_20220101"
}
}

异步执行，如果 reindex 时间过长，建议加上 wait_for_completion=false 的参数条件，这样 reindex 将直接返回 taskId

POST /_reindex?wait_for_completion=false
{
"source": {
"index": "nba"
},
"dest": {
"index": "nba_20220101"
}
}

替换别名

POST /_aliases
{
"actions": [
{
"add": {
"index": "nba_20220101",
"alias": "nba_latest"
}
},
{
"remove": {
"index": "nba",
"alias": "nba_latest"
}
}
]
}

删除旧索引

DELETE /nba

通过别名访问新索引

POST /nba_latest/_search
{
"query": {
"match": {
"displayNameEn": "james"
}
}
}

es之refresh操作

理想的搜索

新的数据一添加到索引中立马就能搜索到，但是真实情况不是这样的

使用链式命令请求，先添加一个文档，再立刻搜索

curl -X PUT localhost:9200/star/_doc/888 -H 'Content-Type:application/json' -d '{ "displayName": "蔡徐坤" }'
curl -X GET localhost:9200/star/_doc/_search?pretty

强制刷新

curl -X PUT localhost:9200/star/_doc/666?refresh -H 'Content-Type:application/json' -d '{ "displayName": "杨超越" }'
curl -X GET localhost:9200/star/_doc/_search?pretty

修改默认更新时间(默认时间是1s)

PUT /star/_settings
{
"index": {
"refresh_interval": "5s"
}
}

将refresh关闭

PUT /star/_settings
{
"index": {
"refresh_interval": "-1"
}
}

es之高亮查询

高亮查询

POST /nba_latest/_search
{
"query": {
"match": {
"displayNameEn": "james"
}
},
"highlight": {
"fields": {
"displayNameEn": {}
}
}
}

自定义高亮查询

POST /nba_latest/_search
{
"query": {
"match": {
"displayNameEn": "james"
}
},
"highlight": {
"fields": {
"displayNameEn": {
"pre_tags": [
"<h1>"
],
"post_tags": [
"</h1>"
]
}
}
}
}

es之查询建议

查询建议是什么?

查询建议，是为了给用户提供更好的搜索体验。包括：词条检查，自动补全

Suggester

Term suggester
Phrase suggester
Completion suggester

字段

text	指定搜索文本
field	获取建议词的搜索字段
analyzer	指定分词器
size	每个词返回的最大建议词数
sort	如何对建议词进行排序，可用选项： score：先按评分排序，再按文档频率排、term顺序； frequency：先按文档频率排，再按评分、term顺序排
suggest_mode	建议模式，控制提供建议词的方式： missing：仅在搜索的词项在索引中不存在时才提供建议词，默认值； popular：仅建议文档频率比搜索词项高的词 always：总是提供匹配的建议词

Term suggester

term 词条建议器，对给输入的文本进行分词，为每个分词提供词项建议

POST /nba_latest/_search
{
"suggest": {
"my-suggestion": {
"text": "jamse hardne",
"term": {
"suggest_mode": "missing",
"field": "displayNameEn"
}
}
}
}

Phrase suggester