大数据Apache Druid（六）：Druid流式数据加载

Druid流式数据加载

一、​​​​​​​​​​​​​​Druid与Kafka整合

1、​​​​​​​使用webui加载Kafka数据

Druid也可以与Kafka整合，直接读取Kafka中某个topic的数据在Druid中进行OLAP分析，步骤如下：

• 启动Kafka,在Kafka中创建topic

#创建Kafka topic
[root@node1 bin]# ./kafka-topics.sh  --zookeeper node3:2181,node4:2181,node5:2181  --create  --topic druid-topic  --partitions 3 --replication-factor 3

#向创建的topic中生产一条数据，这里为了方便后面Druid解析数据
[root@node1 bin]# ./kafka-console-producer.sh  --topic druid-topic --broker-list node1:9092,node2:9092,node3:9092
>{"data_dt":"2021-07-01T08:13:23.000Z","uid":"uid001","loc":"北京","item":"衣服","amount":"100"}

• 进入Druid主页，加载Kafka中数据

进入Druid主页http://node5:8888,点击“Load data”标签：

填写Kafka Server、Topic、点击“Parse data”:

2、​​​​​​​​​​​​​​查询Druid中的数据

点击“Query”编写SQL ，查询DataSource “druid-topic”数据如下：

向Kafka topic druid-topic中继续写入如下数据：

{"data_dt":"2021-07-01T08:20:13.000Z","uid":"uid001","loc":"北京","item":"手机","amount":"200"}
{"data_dt":"2021-07-01T09:24:46.000Z","uid":"uid002","loc":"上海","item":"书籍","amount":"300"}
{"data_dt":"2021-07-01T09:43:42.000Z","uid":"uid002","loc":"上海","item":"书籍","amount":"400"}
{"data_dt":"2021-07-01T09:53:42.000Z","uid":"uid002","loc":"上海","item":"书籍","amount":"500"}
{"data_dt":"2021-07-01T12:19:52.000Z","uid":"uid003","loc":"天津","item":"水果","amount":"600"}
{"data_dt":"2021-07-01T14:53:13.000Z","uid":"uid004","loc":"广州","item":"生鲜","amount":"700"}
{"data_dt":"2021-07-01T15:51:45.000Z","uid":"uid005","loc":"深圳","item":"手机","amount":"800"}
{"data_dt":"2021-07-01T17:21:21.000Z","uid":"uid006","loc":"杭州","item":"电脑","amount":"900"}
{"data_dt":"2021-07-01T20:26:53.000Z","uid":"uid007","loc":"湖南","item":"水果","amount":"1000"}
{"data_dt":"2021-07-01T09:38:11.000Z","uid":"uid008","loc":"山东","item":"书籍","amount":"1100"}

执行聚合查询：select loc,item,sum(amount) as total_amount from "druid-topic" group by loc,item

3、删除Druid数据

删除Druid数据，首先在Ingestion中停止实时接收数据的任务：

然后再DataSource中使所有Segment无效后，再彻底删除对应的数据：

4、​​​​​​​​​​​​​​使用post方式加载Kafka数据

由于前面已经使用Druid加载过当前Kafka“druid-topic”topic的数据，当停止Druid supervisors 中实时读取Kafka topic 任务后，在MySQL 库表“druid.druid_datasource”中会存放当前datasource读取kafka topic的offset信息，如果使用post方式再次提交实时任务生成一样的datasource名称读取相同的Kafka topic时，会获取到该位置的offset信息，所以为了能从头消费Kafka中的数据，我们可以将mysql中“druid.druid_datasource”对应的datasource数据条目删除：

准备json配置，使用postman来提交加载Kafka的任务，配置如下：

{
  "type": "kafka",
  "spec": {
    "ioConfig": {
      "type": "kafka",
      "consumerProperties": {
        "bootstrap.servers": "node1:9092,node2:9092,node3:9092"
      },
      "topic": "druid-topic",
      "inputFormat": {
        "type": "json"
      },
      "useEarliestOffset": true
    },
    "tuningConfig": {
      "type": "kafka"
    },
    "dataSchema": {
      "dataSource": "druid-topic",
      "timestampSpec": {
        "column": "data_dt",
        "format": "iso"
      },
      "dimensionsSpec": {
        "dimensions": [
          {
            "type": "long",
            "name": "amount"
          },
          "item",
          "loc",
          "uid"
        ]
      },
      "granularitySpec": {
        "queryGranularity": "none",
        "rollup": false,
        "segmentGranularity": "day"
      }
    }
  }
}

打开postman，post请求URL:http://node3:8081/druid/indexer/v1/supervisor,在row中写入以上json配置数据提交即可，执行之后可以在Druid页面中看到对应的supervisors和Datasource。

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