ElasticSearch

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发布于: 2021 年 04 月 27 日

简介

MySql&ES 比较

安装

ES 安装

Let’s download the Elasticsearch 5.6.4 tar as follows:

curl -L -O https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.6.4.tar.gz

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Then extract it as follows:

tar -xvf elasticsearch-5.6.4.tar.gz

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It will then create a bunch of files and folders in your current directory. We then go into the bin directory as follows:

cd elasticsearch-5.6.4/bin

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And now we are ready to start our node and single cluster:

./elasticsearch

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Access http://localhost:9200/

ES API

集群健康状态：curl -X GET "localhost:9200/_cat/health?v"集群节点列表：curl -X GET "localhost:9200/_cat/nodes?v"查看所有索引：curl -X GET "localhost:9200/_cat/indices?v"创建一个customer索引：curl -X PUT "localhost:9200/customer?pretty"查看customer索引：curl -X GET "localhost:9200/_cat/indices?v"Put一些数据到我们的"customer"索引：curl -X PUT "localhost:9200/customer/_doc/1?pretty" -H 'Content-Type: application/json' -d'{"name": "John Doe"}'检索这个索引：curl -X GET "localhost:9200/customer/_doc/1?pretty"删除索引：curl -X DELETE "localhost:9200/customer?pretty"更新索引：curl -X POST "localhost:9200/customer/_doc/1/_update?pretty" -H 'Content-Type: application/json' -d' {   "doc": { "name": "Jane Doe", "age": 20 } } 'curl -X POST "localhost:9200/customer/_doc/1/_update?pretty" -H 'Content-Type: application/json' -d' {   "script" : "ctx._source.age += 5" } '删除文档：curl -X DELETE "localhost:9200/customer/_doc/2?pretty"

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Elastcsearch-head 安装

git clone git://github.com/mobz/elasticsearch-head.git//elasticsearch-head是一个基于node.js的前端工程，启动elasticsearch-head的步骤:cd /Users/xxx/software/elasticsearch-headnpm installnpm run start

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访问： http://localhost:9100/

ElasticSearch-Head 使用实践

创建索引模型

PUT http://localhost:9200/test_index_01
{  "mappings": {    "properties": {      "id": {        "type": "long"      },      "name": {        "type": "keyword"      },      "description": {        "type": "text",        "fields": {          "keyword": {            "type": "keyword",            "ignore_above": 256          }        }      }    }  }}

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查看索引模型

GET http://localhost:9200/test_index_01

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创建索引

POST http://localhost:9200/test_index_01/_doc{  "id": 1,  "name": "Zhang San",  "description": "This is detail information"}

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查询索引

//根据ID查询POST http://localhost:9200/test_index_01/_search{  "query": {    "match": {      "id": 1    }  }}

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更新索引

POST http://localhost:9200/test_index_01/_doc/geziEnkBkShgFG4suzh6{  "id": 1,  "name": "Zhang San",  "description": "This is detail information v2"}

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删除索引

DELETE http://localhost:9200/test_index_01/_doc/f-zKEnkBkShgFG4sIjgA

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ES 查询表达式

Query DSL

Elasticsearch provides a full Query DSL (Domain Specific Language) based on JSON to define queries. Think of the Query DSL as an AST (Abstract Syntax Tree) of queries, consisting of two types of clauses:

Leaf query clauses

Leaf query clauses look for a particular value in a particular field, such as the match, term or range queries. These queries can be used by themselves.

Compound query clauses

Compound query clauses wrap other leaf or compound queries and are used to combine multiple queries in a logical fashion (such as the bool or dis_max query), or to alter their behaviour (such as the constant_score query).

Allow expensive queries

Certain types of queries will generally execute slowly due to the way they are implemented, which can affect the stability of the cluster. Those queries can be categorised as follows:

Queries that need to do linear scans to identify matches:
script queries
Queries that have a high up-front cost:
fuzzy queries (except on wildcard fields)
regexp queries (except on wildcard fields)
prefix queries (except on wildcard fields or those without index_prefixes)
wildcard queries (except on wildcard fields)
range queries on text and keyword fields
Joining queries
Queries on deprecated geo-shapes
Queries that may have a high per-document cost:
script_score queries
percolate queries

The execution of such queries can be prevented by setting the value of the search.allow_expensive_queries setting to false (defaults to true).

附录

发布于: 2021 年 04 月 27 日阅读数: 24

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ElasticSearch

简介

MySql&ES 比较

安装

ES 安装

ES API

Elastcsearch-head 安装

ElasticSearch-Head 使用实践

创建索引模型

查看索引模型

创建索引

查询索引

更新索引

删除索引

ES 查询表达式

Query DSL

Leaf query clauses

Compound query clauses

Allow expensive queries

附录

GitHub

Doc

Elasticsearch 权威指南

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