ES+kibana

ES 是一款开源的分布式搜索引擎

下载，解压，修改config/elasticsearch.yml里面根security两个地方的选项为false,运行bin/elasticsearch，测试9200端口
https://www.ruanyifeng.com/blog/2017/08/elasticsearch.html

curl -XGET 'http://localhost:9200/' -H 'Content-Type: application/json'
{
  "name" : "tddeMacBook-Air.local",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "2uSPQGtXRu-xIIzQVLVcAw",
  "version" : {
    "number" : "8.4.0",
    "build_flavor" : "default",
    "build_type" : "tar",
    "build_hash" : "f56126089ca4db89b631901ad7cce0a8e10e2fe5",
    "build_date" : "2022-08-19T19:23:42.954591481Z",
    "build_snapshot" : false,
    "lucene_version" : "9.3.0",
    "minimum_wire_compatibility_version" : "7.17.0",
    "minimum_index_compatibility_version" : "7.0.0"
  },
  "tagline" : "You Know, for Search"
}

这样就说明成功了

概念

es本质上是一个分布式数据库，一台机器上一个实例为一个node

Index:
ES会把数据分词后建立索引，使用反向索引来搜索数据

查看所有索引

curl -X GET 'http://localhost:9200/_cat/indices?v'

Document:
index里面的单条记录被称为文档，多个文档组成一个index，同一个index下的document最好拥有相同构造以保证搜索效率

Type：
Type是对index里面document的虚拟分组

基础操作

https://blog.csdn.net/UbuntuTouch/article/details/98871531

增：索引会自动创建

curl -XPUT 'http://localhost:9200/twitter/_doc/1?pretty' -H 'Content-Type: application/json' -d '
{
    "user": "kimchy",
    "post_date": "2009-11-15T13:12:00",
    "message": "Trying out Elasticsearch, so far so good?"
}'
 
curl -XPUT 'http://localhost:9200/twitter/_doc/2?pretty' -H 'Content-Type: application/json' -d '
{
    "user": "kimchy",
    "post_date": "2009-11-15T14:12:12",
    "message": "Another tweet, will it be indexed?"
}'
 
curl -XPUT 'http://localhost:9200/twitter/_doc/3?pretty' -H 'Content-Type: application/json' -d '
{
    "user": "elastic",
    "post_date": "2010-01-15T01:46:38",
    "message": "Building the site, should be kewl"
}'

查
精准：

curl -XGET 'http://localhost:9200/twitter/_doc/1?pretty=true'
{
  "_index" : "twitter",
  "_id" : "1",
  "_version" : 1,
  "_seq_no" : 0,
  "_primary_term" : 1,
  "found" : true,
  "_source" : {
    "user" : "kimchy",
    "post_date" : "2009-11-15T13:12:00",
    "message" : "Trying out Elasticsearch, so far so good?"
  }
}

搜索

curl -XGET 'http://localhost:9200/twitter/_search?q=user:kimchy&pretty=true'
{
  "took" : 69,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 0.4700036,
    "hits" : [
      {
        "_index" : "twitter",
        "_id" : "1",
        "_score" : 0.4700036,
        "_source" : {
          "user" : "kimchy",
          "post_date" : "2009-11-15T13:12:00",
          "message" : "Trying out Elasticsearch, so far so good?"
        }
      },
      {
        "_index" : "twitter",
        "_id" : "2",
        "_score" : 0.4700036,
        "_source" : {
          "user" : "kimchy",
          "post_date" : "2009-11-15T14:12:12",
          "message" : "Another tweet, will it be indexed?"
        }
      }
    ]
  }
}

JSON格式的查询

curl -XGET 'http://localhost:9200/twitter/_search?pretty=true' -H 'Content-Type: application/json' -d '
{
    "query" : {
        "match" : { "user": "kimchy" }
    }
}'
{
  "took" : 6,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 0.4700036,
    "hits" : [
      {
        "_index" : "twitter",
        "_id" : "1",
        "_score" : 0.4700036,
        "_source" : {
          "user" : "kimchy",
          "post_date" : "2009-11-15T13:12:00",
          "message" : "Trying out Elasticsearch, so far so good?"
        }
      },
      {
        "_index" : "twitter",
        "_id" : "2",
        "_score" : 0.4700036,
        "_source" : {
          "user" : "kimchy",
          "post_date" : "2009-11-15T14:12:12",
          "message" : "Another tweet, will it be indexed?"
        }
      }
    ]
  }
}

删除

curl -X DELETE 'localhost:9200/index_name'

kibana

kibana是es配套的一个可视化工具，需要下载和es相同版本号的kibana才能连上

下载解压，修改config/kibana.yml,改下连的es的地址，另外有个语言选项可改可不改

bin/kibana启动，访问5601端口，配置索引

/elastic/v7

go get -u github.com/olivere/elastic/v7

这是个第三方库，据说官方库不咋好用。应该下载对应版本的，但是我es下高了....不过好在经过测试，基础的一些功能还是兼容的

package EScli

import (
    "context"
    "fmt"

    "github.com/olivere/elastic/v7"
    "github.com/sirupsen/logrus"
)

type Twinfo struct {
    User      string `json:"user"`
    Post_date string `json:"post_date"`
    Message   string `json:"message"`
}

func Connes() {
    cli, err := elastic.NewClient(elastic.SetURL("http://127.0.0.1:9200"), elastic.SetSniff(false)) // 这里有很多可选项，按需选择

    if err != nil {
        logrus.Error("Failed to connect ES", err)
    }
    var msg = Twinfo{User: "zhangsan", Post_date: "2022-08-22T17:12:00", Message: "Vice versa"}
    put, err := cli.Index().Index("twitter").BodyJson(msg).Do(context.Background())
    if err != nil {
        logrus.Error("Failed to inject ES")
    }
    fmt.Printf("index:%s\ntype:%s\nid:%s\n", put.Index, put.Type, put.Id)
}