我想使用foreachpartition对dataframe进行分区以达到并行往数据库写数据的操作,但是与数据库的连接已经在父类中的这个方法中创建过了,我有什么方法可以使spark程序在运行的时候不会报Task not serializable
override def load(dataFrame: DataFrame, delta: Boolean): DataFrame = {
......
dataFrame.repartition(10).foreachPartition(row => {
loadMainData( dataFrame,false , rbkMainFactTable )
for(rbkUnionTable<-rbkUnionFactTableList) {
loadRbkUnionData( dataFrame,false , rbkUnionTable )
}
for(rbkFactTable <- rbkFactTableLists){
loadRbkData(dataFrame, false ,rbkFactTable)
}
})
dataFrame
//writeToTable(dataFrame: DataFrame, delta: Boolean)
}
这个问题是因为Spark需要序列化。你得将数据库连接对象声明为transient(即不参与序列化),然后在分区中重新创建连接。
override def load(dataFrame: DataFrame, delta: Boolean): DataFrame = {
......
dataFrame.repartition(10).foreachPartition(rows => {
// Create a new instance of the database connection object
val conn = createNewConnection()
try {
loadMainData(rows, false, rbkMainFactTable, conn)
for (rbkUnionTable <- rbkUnionFactTableList) {
loadRbkUnionData(rows, false, rbkUnionTable, conn)
}
for (rbkFactTable <- rbkFactTableLists) {
loadRbkData(rows, false, rbkFactTable, conn)
}
} finally {
// Close the connection after processing the partition
conn.close()
}
})
dataFrame
//writeToTable(dataFrame: DataFrame, delta: Boolean)
}