添加元数据服务
元数据服务就是对元数据提供存取功能的服务。元数据就是系统定义的基本信息，比如一张相片的名字，版本，拍摄时间，散列值等。客户端和接口服务之间根据对象的名字来引用一个对象，一个对象可以有多个版本，除了删除标志外，每个版本指向数据服务的一个实际的数据存储
ES的基本使用
ES或者任意的一个分布式数据库都可以作为元数据服务
启动（windows）elasticsearch-7.6.2-windows-x86_64\elasticsearch-7.6.2\bin\elasticsearch.bat
成功http://192.168.7.6:9200/people
链接服务器的golang操作
全文搜索引擎 Elasticsearch 入门教程 作者: 阮一峰
ES官方中文手册
添加索引
package mainimport ("context""fmt""github.com/olivere/elastic"
)func main(){Client, err := elastic.NewClient(elastic.SetURL("http://192.168.7.6:9200"))fmt.Println(Client, err)name := "people2"Client.CreateIndex(name).Do(context.Background())
}
插入和查找
func main(){Client, err := elastic.NewClient(elastic.SetURL("http://192.168.7.6:9200"))fmt.Println(Client, err)name := "people2"data := `{"name": "wali","country": "Chian","age": 30,"date": "1987-03-07"}`_, err = Client.Index().Index(name).Type("man1").Id("1").BodyJson(data).Do(context.Background())get, err := Client.Get().Index(name).Type("man1").Id("1").Do(context.Background())fmt.Println(get, err)
ES的API访问（curl）
常用操作
浏览ES服务器
$ curl -XGET http://localhost:9200/
{"name" : "DESKTOP-PVBHUQ5","cluster_name" : "elasticsearch","cluster_uuid" : "79x294HmR3iDFIQ2M3-_Kg","version" : {"number" : "7.6.2","build_flavor" : "default","build_type" : "zip","build_hash" : "ef48eb35cf30adf4db14086e8aabd07ef6fb113f","build_date" : "2020-03-26T06:34:37.794943Z","build_snapshot" : false,"lucene_version" : "8.4.0","minimum_wire_compatibility_version" : "6.8.0","minimum_index_compatibility_version" : "6.0.0-beta1"},"tagline" : "You Know, for Search"
}
插入索引
$curl -XPUT http://localhost:9200/people{"acknowledged":true,"shards_acknowledged":true,"index":"people"}
往索引库中新增数据
curl http://localhost:9200/people/ -XPOST -d '{"author" : "a", "name":"a"}'
查看集群健康状况
curl -XGET http://localhost:9200/_cluster/health?format=yaml
---
cluster_name: "elasticsearch"
status: "yellow"
timed_out: false
number_of_nodes: 1
number_of_data_nodes: 1
active_primary_shards: 3
active_shards: 3
relocating_shards: 0
initializing_shards: 0
unassigned_shards: 3
delayed_unassigned_shards: 0
number_of_pending_tasks: 0
number_of_in_flight_fetch: 0
task_max_waiting_in_queue_millis: 0
active_shards_percent_as_number: 50.0
获取ES所有索引
$~curl -XGET http://localhost:9200/_cat/indices
yellow open people2 OIyNXAzwSvCXdRTM1OCcug 1 1 1 0 10.2kb 10.2kb
yellow open bigdata_p GlbTA7_xSVK26L_oU_pVKw 1 1 0 0 283b 283b
yellow open people AwsSuR6VS_uCfkNvqDxc6Q 1 1 0 0 283b 283b
获取索引字段
C:\Users\HodgeKou> curl -XGET http://localhost:9200/people2/_mapping?format=yaml
---
people2:mappings:properties:age:type: "long"country:type: "text"fields:keyword:type: "keyword"ignore_above: 256date:type: "date"name:type: "text"fields:keyword:type: "keyword"ignore_above: 256
新建索引
curl -XPUT localhost:9200/people2
删除索引
curl -XDELETE localhost:9200/people?format=yaml
插入单条数据
curl -XPUT localhost:9200/people/external/1?format=yaml' -d
quote> { "name":"paxi"}'
查询单条数据
curl -XGET localhost:9200/people2/_search?pretty
删除单条数据
curl -XDELETE localhost:9200/people2/external/3?format=yamlES进行更新PUT请求时，会重发数据
第一次PUT
$ curl -X PUT 'localhost:9200/accounts/person/1' -d '
{"user": "张三","title": "工程师","desc": "数据库管理"
}'
---------------------------------------------------
{"_index":"accounts","_type":"person","_id":"1","_version":1,"result":"created","_shards":{"total":2,"successful":1,"failed":0},"created":true
}
第二次PUT，更改了数据，banben_version加1
$ curl -X PUT 'localhost:9200/accounts/person/1' -d '
{"user" : "张三","title" : "工程师","desc" : "数据库管理，软件开发"
}' ----------------------------------------------------
{----"_index":"accounts","_type":"person","_id":"1","_version":2,"result":"updated","_shards":{"total":2,"successful":1,"failed":0},"created":false
}
上面代码中，我们将原始数据从"数据库管理"改成"数据库管理，软件开发"。 返回结果里面，有几个字段发生了变化。"_version" : 2,
"result" : "updated",
"created" : false
