[SPARK-10625] Spark SQL JDBC read/write is unable to handle JDBC Drivers that adds unserializable objects into connection properties - ASF JIRA

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Details

Type: Bug
Status: Resolved
Priority: Major
Resolution: Incomplete
Affects Version/s: 1.4.1, 1.5.0
Fix Version/s: None
Component/s: SQL
Labels:
- bulk-closed
- jdbc
- spark
- sparksql
Environment:

Ubuntu 14.04

Description

Some JDBC drivers (e.g. SAP HANA) tries to optimize connection pooling by adding new objects into the connection properties, which is then reused by Spark to be deployed to workers. When some of these new objects are unable to be serializable it will trigger an org.apache.spark.SparkException: Task not serializable. The following test code snippet demonstrate this problem by using a modified H2 driver:

test("INSERT to JDBC Datasource with UnserializableH2Driver") {

object UnserializableH2Driver extends org.h2.Driver {

override def connect(url: String, info: Properties): Connection =

{ val result = super.connect(url, info) info.put("unserializableDriver", this) result }

override def getParentLogger: Logger = ???
}

import scala.collection.JavaConversions._

val oldDrivers = DriverManager.getDrivers.filter(_.acceptsURL("jdbc:h2:")).toSeq
oldDrivers.foreach

{ DriverManager.deregisterDriver }

DriverManager.registerDriver(UnserializableH2Driver)

sql("INSERT INTO TABLE PEOPLE1 SELECT * FROM PEOPLE")
assert(2 === sqlContext.read.jdbc(url1, "TEST.PEOPLE1", properties).count)
assert(2 === sqlContext.read.jdbc(url1, "TEST.PEOPLE1", properties).collect()(0).length)

DriverManager.deregisterDriver(UnserializableH2Driver)
oldDrivers.foreach

{ DriverManager.registerDriver }

}