ApsaraDB for ClickHouse：從Spark匯入

前提條件

• 已將本地機器的IP地址添加到雲資料庫ClickHouse的白名單中。如何添加，請參見設定白名單。
• 已建立與匯入資料結構類型對應的雲資料庫ClickHouse表。如何建立，請參見建立表。

操作步驟

1. 準備Spark程式目錄結構。

    find .
   .
   ./build.sbt
   ./src
   ./src/main
   ./src/main/scala
   ./src/main/scala/com
   ./src/main/scala/com/spark
   ./src/main/scala/com/spark/test
   ./src/main/scala/com/spark/test/WriteToCk.scala

2. 編輯build.sbt設定檔並添加依賴。

   name := "Simple Project"
   
   version := "1.0"
   
   scalaVersion := "2.12.10"
   
   libraryDependencies += "org.apache.spark" %% "spark-sql" % "3.0.0"
   
   libraryDependencies += "ru.yandex.clickhouse" % "clickhouse-jdbc" % "0.2.4"

3. 建立WriteToCk.scala資料並寫入程式檔案。

   package com.spark.test
   
   import java.util
   import java.util.Properties
   
   import org.apache.spark.sql.execution.datasources.jdbc.JDBCOptions
   import org.apache.spark.SparkConf
   import org.apache.spark.sql.{SaveMode, SparkSession}
   import org.apache.spark.storage.StorageLevel
   
   object WriteToCk {
     val properties = new Properties()
     properties.put("driver", "ru.yandex.clickhouse.ClickHouseDriver")
     properties.put("user", "<yourUserName>")
     properties.put("password", "<yourPassword>")
     properties.put("batchsize","100000")
     properties.put("socket_timeout","300000")
     properties.put("numPartitions","8")
     properties.put("rewriteBatchedStatements","true")
   
     val url = "jdbc:clickhouse://<yourUrl>:8123/default"
     val table = "<yourTableName>"
   
     def main(args: Array[String]): Unit = {
       val sc = new SparkConf()
       sc.set("spark.driver.memory", "1G")
       sc.set("spark.driver.cores", "4")
       sc.set("spark.executor.memory", "1G")
       sc.set("spark.executor.cores", "2")
   
       val session = SparkSession.builder().master("local[*]").config(sc).appName("write-to-ck").getOrCreate()
   
       val df = session.read.format("csv")
         .option("header", "true")
         .option("sep", ",")
         .option("inferSchema", "true")
         .load("<yourFilePath>")
         .selectExpr(
           "colName1",
           "colName2",
           "colName3",
            ...
         )
         .persist(StorageLevel.MEMORY_ONLY_SER_2)
       println(s"read done")
   
       df.write.mode(SaveMode.Append).option(JDBCOptions.JDBC_BATCH_INSERT_SIZE, 100000).jdbc(url, table, properties)
       println(s"write done")
   
       df.unpersist(true)
     }
   }

   參數說明如下。

   參數	說明
   yourUserName	雲資料庫ClickHouse中建立的資料庫帳號。
   yourPassword	資料庫帳號的密碼。
   yourUrl	資料庫連接地址。
   yourTableName	雲資料庫ClickHouse中建立的表名。
   yourFilePath	匯入資料檔案的儲存路徑，包含檔案地址和檔案名稱。
   colName1,colName2,colName3	雲資料庫ClickHouse表的列名。

4. 編譯打包。

   sbt package

5. 運行。

   ${SPARK_HOME}/bin/spark-submit  --class "com.spark.test.WriteToCk"  --master local[4] --conf "spark.driver.extraClassPath=${HOME}/.m2/repository/ru/yandex/clickhouse/clickhouse-jdbc/0.2.4/clickhouse-jdbc-0.2.4.jar" --conf "spark.executor.extraClassPath=${HOME}/.m2/repository/ru/yandex/clickhouse/clickhouse-jdbc/0.2.4/clickhouse-jdbc-0.2.4.jar" target/scala-2.12/simple-project_2.12-1.0.jar