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[SPARK-17350][SQL] Disable default use of KryoSerializer in Thrift Server

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In SPARK-4761 / #3621 (December 2014) we enabled Kryo serialization by default in the Spark Thrift Server. However, I don't think that the original rationale for doing this still holds now that most Spark SQL serialization is now performed via encoders and our UnsafeRow format.

In addition, the use of Kryo as the default serializer can introduce performance problems because the creation of new KryoSerializer instances is expensive and we haven't performed instance-reuse optimizations in several code paths (including DirectTaskResult deserialization).

Given all of this, I propose to revert back to using JavaSerializer as the default serializer in the Thrift Server.

/cc liancheng

Author: Josh Rosen <joshrosen@databricks.com>

Closes #14906 from JoshRosen/disable-kryo-in-thriftserver.
This commit is contained in:
Josh Rosen 2016-11-01 16:23:47 -07:00 committed by Reynold Xin
parent 01dd008301
commit 6e6298154a
2 changed files with 2 additions and 13 deletions
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5
docs/configuration.md
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@ -767,7 +767,7 @@ Apart from these, the following properties are also available, and may be useful
</tr>
<tr>
<td><code>spark.kryo.referenceTracking</code></td>
<td>true (false when using Spark SQL Thrift Server)</td>
<td>true</td>
<td>
Whether to track references to the same object when serializing data with Kryo, which is
necessary if your object graphs have loops and useful for efficiency if they contain multiple
@ -838,8 +838,7 @@ Apart from these, the following properties are also available, and may be useful
<tr>
<td><code>spark.serializer</code></td>
<td>
org.apache.spark.serializer.<br />JavaSerializer (org.apache.spark.serializer.<br />
KryoSerializer when using Spark SQL Thrift Server)
org.apache.spark.serializer.<br />JavaSerializer
</td>
<td>
Class to use for serializing objects that will be sent over the network or need to be cached

10
sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkSQLEnv.scala
View file

@ -19,8 +19,6 @@ package org.apache.spark.sql.hive.thriftserver
import java.io.PrintStream
import scala.collection.JavaConverters._
import org.apache.spark.{SparkConf, SparkContext}
import org.apache.spark.internal.Logging
import org.apache.spark.sql.{SparkSession, SQLContext}
@ -37,8 +35,6 @@ private[hive] object SparkSQLEnv extends Logging {
def init() {
if (sqlContext == null) {
val sparkConf = new SparkConf(loadDefaults = true)
val maybeSerializer = sparkConf.getOption("spark.serializer")
val maybeKryoReferenceTracking = sparkConf.getOption("spark.kryo.referenceTracking")
// If user doesn't specify the appName, we want to get [SparkSQL::localHostName] instead of
// the default appName [SparkSQLCLIDriver] in cli or beeline.
val maybeAppName = sparkConf
@ -47,12 +43,6 @@ private[hive] object SparkSQLEnv extends Logging {
sparkConf
.setAppName(maybeAppName.getOrElse(s"SparkSQL::${Utils.localHostName()}"))
.set(
"spark.serializer",
maybeSerializer.getOrElse("org.apache.spark.serializer.KryoSerializer"))
.set(
"spark.kryo.referenceTracking",
maybeKryoReferenceTracking.getOrElse("false"))
val sparkSession = SparkSession.builder.config(sparkConf).enableHiveSupport().getOrCreate()
sparkContext = sparkSession.sparkContext