Elasticsearch란

Apache Lucene 기반으로 개발 된 실시간 분산 검색 및 분석 엔진

RDBMS와의 차이

도커로 설치해보기

$ docker pull docker.elastic.co/elasticsearch/elasticsearch:7.6.2

$ docker run -d --name elasticsearch -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" docker.elastic.co/elasticsearch/elasticsearch:7.6.2

9200: http 포트, 9300: 전송포트

• 생성 - /{index}/{type}/{id}

  id를 입력하지 않으면 랜덤한 문자열을 id로 생성한다.

  Request

  POST http://localhost:9200/database/user/1
  {
    "name": "zkdlu",
    "age": 25
  }
  

  Response

  {
    "_index": "database",
    "_type": "user",
    "_id": "5",
    "_version": 1,
    "result": "created",
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 5,
    "_primary_term": 1
  }
  

• 수정 - /{index}/{type{id}}

Request

  PUT http://localhost:9200/database/user/1
  {
    "name": "zkdlu",
    "age": 24
  }

Response

  {
     "_index": "database",
     "_type": "user",
     "_id": "1",
     "_version": 3,
     "result": "updated",
     "_shards": {
         "total": 2,
         "successful": 1,
         "failed": 0
     },
     "_seq_no": 6,
     "_primary_term": 1
  }

• 조회 - /{index}/{type}/{id}

Request

  GET http://localhost:9200/database/user/1

Response

{
      "_index": "database",
      "_type": "user",
      "_id": "1",
      "_version": 3,
      "_seq_no": 6,
      "_primary_term": 1,
      "found": true,
      "_source": {
          "name": "zkdlu",
          "age": 24
      }
  }

• 삭제 - /{index}/{type}/{id}

Request

  DELETE http://localhost:9200/database/user/1

Response

{
      "_index": "database",
      "_type": "user",
      "_id": "1",
      "_version": 4,
      "result": "deleted",
      "_shards": {
          "total": 2,
          "successful": 1,
          "failed": 0
      },
      "_seq_no": 7,
      "_primary_term": 1
  }

• 전체 조회 - /{index}/{type}/_search

Request

  GET http://localhost:9200/database/user/_search

Response

{
      "took": 945,
      "timed_out": false,
      "_shards": {
          "total": 1,
          "successful": 1,
          "skipped": 0,
          "failed": 0
      },
      "hits": {
          "total": {
              "value": 4,
              "relation": "eq"
          },
          "max_score": 1.0,
        "hits": [
             {
                 "_index": "database",
                 "_type": "user",
                 "_id": "2",
                 "_score": 1.0,
                 "_source": {
                     "name": "zkdlu2",
                     "age": 25
                 }
             },
             ... 생략

• 전체 조건 조회 - /{index}/{type}/_search?q={key}:{value}

Request

  GET localhost:9200/database/user/_search?q=name:zkdlu

Response

{
      "took": 2,
      "timed_out": false,
      "_shards": {
          "total": 1,
          "successful": 1,
          "skipped": 0,
          "failed": 0
      },
      "hits": {
          "total": {
              "value": 1,
              "relation": "eq"
          },
          "max_score": 1.0296195,
          "hits": [
              {
                  "_index": "database",
                  "_type": "user",
                  "_id": "1",
                  "_score": 1.0296195,
                  "_source": {
                      "name": "zkdlu",
                      "age": 25
                  }
              }
          ]
      }
  }

버전 업그레이드

작성 후 알았는데 위의 API는 Elasticsearch 6.x 버전에서 사용 되는 api이다.

7.x 로 올라오면서 Type 구조를 삭제하고 Document는 _doc으로 대체되었습니다.

변경 된 API 비교

• Search

  API	6.x	7.x
  search	/{index}/{type}/_search	{index}/_search
  msearch	/{index}/{type}/_msearch	/{index}/_msearch
  count	/{index}/{type}/_count	/{index}/_count
  explain	/{index}/{type}/{id}/_explain	/{index}/_explain/{id}
  search template	/{index}/{type}/_search/template	/{index}/_search/template
  msearch template	/{index}/{type}/_msearch/template	/{index}/_msearch/template

• Document

  API	6.x	7.x
  index	{index}/{type}/{id}	/{index}/_doc/{id}
  delete	/{index}/{type}/{id}	/{index}/_doc/{id}
  get	/{index}/{type}/{id}	/{index}/_doc/{id}
  update	/{index}/{type}/{id}/_update	/{index}/_update/{id}
  get source	/{index}/{type}/{id}/_source	/{index}/_source/{id}
  bulk	/{index}/{type}/_bulk	/{index}/_bulk
  mget	/{index}/{type}/_mget	/{index}/_mget
  termvectors	/{index}/{type}/{id}/_termvector	/{index}/_termvector/{id}
  mtermvectors	/{index}/{type}/_mtermvectors	/{index}/_mtermvectors

• Index

  API	6.x	7.x
  create index	/{index}	ㅡ
  get mapping	/{index}/_mapping/{type}	/{index}/_mapping
  put mapping	/{index}/_mapping/{type}	/{index}/_mapping
  get field mapping	/{index}/{type}/_mapping/field/{fields}	/{index}/_mapping/field/{fields}
  get template	/_template/{template}	ㅡ
  put template	/_template/{template}	ㅡ