spark 计算结果写入mysql 案例及常见问题解决

package com.jxd

import org.apache.spark.SparkContext
import org.apache.spark.SparkConf
import java.sql.Connection
import java.sql.DriverManager
object hello {
def main(args: Array[String]): Unit = {
var conf = new SparkConf().setAppName("Hello World")
var sc = new SparkContext(conf)
var input = sc.textFile("test/hello", 2)
var count = input.flatMap(name => name.split(" ")).map((_, 1)).reduceByKey(((a, b) => a + b))
count.foreachPartition(insertToMysql)

}
def insertToMysql(iterator: Iterator[(String, Int)]): Unit = {
val driver = "com.mysql.jdbc.Driver"
val url = "jdbc:mysql://192.168.10.58:3306/test"
val username = "root"
val password = "1"
var connectionMqcrm: Connection = null
Class.forName(driver)
connectionMqcrm = DriverManager.getConnection(url, username, password)
val sql = "INSERT INTO t_spark (`name`,`num`) VALUES (?,?)"
iterator.foreach(data => {
val statement = connectionMqcrm.prepareStatement(sql)
statement.setString(1, data._1)
statement.setInt(2, data._2)
var result = statement.executeUpdate()
if (result == 1) {
println("写入mysql成功.............")
}
})
}
}

Caused by: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at com.jxd.hello$.insertToMysql(hello.scala:22)
at com.jxd.hello$$anonfun$main$1.apply(hello.scala:13)
at com.jxd.hello$$anonfun$main$1.apply(hello.scala:13)
at org.apache.spark.rdd.RDD$$anonfun$foreachPartition$1$$anonfun$apply$29.apply(RDD.scala:926)
at org.apache.spark.rdd.RDD$$anonfun$foreachPartition$1$$anonfun$apply$29.apply(RDD.scala:926)
at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:2069)
at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:2069)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:87)
at org.apache.spark.scheduler.Task.run(Task.scala:108)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:338)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

spark1.4以前版本 在/spark/jars 加入mysql驱动 并不起作用需在提交任务指定mysql驱动包

例如：

spark-submit --master spark://192.168.10.160:7077 --driver-class-path /usr/spark/jars/mysql-connector-java-5.1.18-bin.jar --class com.jxd.hello /usr/spark/wc.jar /usr/spark/test/hello

高版本如 spark2.2已经修复此问题

注意：集群中每一个server都得加入mysql驱动包(建议先加一个 然后采用远程复制)

集群所有节点加完mysql驱动包后直接提交即可

park-submit --master spark://192.168.10.160:7077 --class com.jxd.hello /usr/spark/wc.jar /usr/spark/test/hello