Elasticsearch重建索引-修改索引字段类型

如果不允许修改索引字段类型，只能重建索引

步骤

1. 新建一个索引
2. 数据迁移
3. 删除旧索引
4. 别名引用

1、准备工作

1.1、查看版本号

GET /

响应

{
  "name": "jxZZibZ",
  "cluster_name": "elasticsearch",
  "cluster_uuid": "23IcxgHqTniM4wOGyl03Pw",
  "version": {
    "number": "5.6.16",
    "build_hash": "3a740d1",
    "build_date": "2019-03-13T15:33:36.565Z",
    "build_snapshot": false,
    "lucene_version": "6.6.1"
  },
  "tagline": "You Know, for Search"
}

可以看到，我所使用的ES 版本号为：5.6.16

1.2、创建旧索引

旧索引名为old-index，包含2个字段：id、username

PUT /old-index
{
  "mappings": {
    "doc": {
      "properties": {
        "id": {
          "type": "integer"
        },
        "username": {
          "type": "text"
        }
      }
    }
  }
}

响应

{
  "acknowledged": true,
  "shards_acknowledged": true,
  "index": "old-index"
}

1.3、添加两条数据

POST /old-index/doc
{
  "id": 1000,
  "username": "root"
}

POST /old-index/doc
{
  "id": 1001,
  "username": "other"
}

1.4、查看数据

GET /old-index/_search

响应

{
  "took": 0,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 2,
    "max_score": 1,
    "hits": [
      {
        "_index": "old-index",
        "_type": "doc",
        "_id": "AY1pDh-BNp3AgKn6mtEj",
        "_score": 1,
        "_source": {
          "id": 1000,
          "username": "root"
        }
      },
      {
        "_index": "old-index",
        "_type": "doc",
        "_id": "AY1pDikjNp3AgKn6mtEk",
        "_score": 1,
        "_source": {
          "id": 1001,
          "username": "other"
        }
      }
    ]
  }
}

2、新建一个索引

2.1、查看旧索引的mapping

GET /old-index/_mapping

响应

{
  "old-index": {
    "mappings": {
      "doc": {
        "properties": {
          "id": {
            "type": "integer"
          },
          "username": {
            "type": "text"
          }
        }
      }
    }
  }
}

2.2、新建索引

新的索引名为new-reindex，将id 字段的类型从integer 改为keyword

PUT /new-reindex
{
  "mappings": {
    "doc": {
      "properties": {
        "id": {
          "type": "keyword"
        },
        "username": {
          "type": "text"
        }
      }
    }
  }
}

3、数据迁移

3.1、使用异步任务迁移数据

POST /_reindex?wait_for_completion=false
{
  "source": {
    "index": "old-index",
    "size": 10000
  },
  "dest": {
    "index": "new-index"
  }
}

响应

{
  "task": "jxZZibZPQ_mViMJHQyFz5w:7335"
}

如果数据量较大，容易出现 Gateway Time-out ，所以我添加了参数wait_for_completion=false，让其后台执行

{
  "statusCode": 504,
  "error": "Gateway Time-out",
  "message": "Client request timeout"
}

3.2、查看任务状态

GET /_tasks/jxZZibZPQ_mViMJHQyFz5w:7335

{
  "completed": true,
  "task": {
    "node": "jxZZibZPQ_mViMJHQyFz5w",
    "id": 7335,
    "type": "transport",
    "action": "indices:data/write/reindex",
    "status": {
      "total": 2,
      "updated": 0,
      "created": 2,
      "deleted": 0,
      "batches": 1,
      "version_conflicts": 0,
      "noops": 0,
      "retries": {
        "bulk": 0,
        "search": 0
      },
      "throttled_millis": 0,
      "requests_per_second": -1,
      "throttled_until_millis": 0
    },
    "description": "reindex from [old-index] to [new-index]",
    "start_time_in_millis": 1706864890889,
    "running_time_in_nanos": 105811530,
    "cancellable": true
  },
  "response": {
    "took": 105,
    "timed_out": false,
    "total": 2,
    "updated": 0,
    "created": 2,
    "deleted": 0,
    "batches": 1,
    "version_conflicts": 0,
    "noops": 0,
    "retries": {
      "bulk": 0,
      "search": 0
    },
    "throttled_millis": 0,
    "requests_per_second": -1,
    "throttled_until_millis": 0,
    "failures": []
  }
}

4、删除旧索引

4.1、确认索引数据

查看新旧索引中的数据总量是否相等

GET /old-index/_count

GET /new-index/_count

响应

{
  "count": 2,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  }
}

4.2、删除旧索引

确认数据已迁移完成，可以删除旧的索引了

DELETE /old-index

响应

{
  "acknowledged": true
}

5、别名引用

5.1、创建别名

PUT /new-index/_alias/old-index

响应

{
  "acknowledged": true
}

5.2、查看别名

GET _cat/aliases

old-index    new-index     - - -

5.3、使用别名

新旧索引都可以使用了

GET /old-index/_search

GET /new-index/_search

参考文章

• 如何在Elasticsearch中改变字段类型？