From c2a8aaede7b7d59a763f85b5271bbe14d5389be2 Mon Sep 17 00:00:00 2001
From: Dongjoon Hyun <dongjoon@apache.org>
Date: Mon, 13 Oct 2025 19:43:43 -0700
Subject: [PATCH] [SPARK-53896][CORE] Enable
 `spark.io.compression.lzf.parallel.enabled` by default

---
 .../main/scala/org/apache/spark/internal/config/package.scala   | 2 +-
 docs/configuration.md                                           | 2 +-
 docs/core-migration-guide.md                                    | 1 +
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/core/src/main/scala/org/apache/spark/internal/config/package.scala b/core/src/main/scala/org/apache/spark/internal/config/package.scala
index d413d06ffc94f..94fe31e1cd8cb 100644
--- a/core/src/main/scala/org/apache/spark/internal/config/package.scala
+++ b/core/src/main/scala/org/apache/spark/internal/config/package.scala
@@ -2137,7 +2137,7 @@ package object config {
       .doc("When true, LZF compression will use multiple threads to compress data in parallel.")
       .version("4.0.0")
       .booleanConf
-      .createWithDefault(false)
+      .createWithDefault(true)
 
   private[spark] val IO_WARNING_LARGEFILETHRESHOLD =
     ConfigBuilder("spark.io.warning.largeFileThreshold")
diff --git a/docs/configuration.md b/docs/configuration.md
index 573b485f7e2df..b999a6ee25778 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -1918,7 +1918,7 @@ Apart from these, the following properties are also available, and may be useful
 </tr>
 <tr>
   <td><code>spark.io.compression.lzf.parallel.enabled</code></td>
-  <td>false</td>
+  <td>true</td>
   <td>
     When true, LZF compression will use multiple threads to compress data in parallel.
   </td>
diff --git a/docs/core-migration-guide.md b/docs/core-migration-guide.md
index a738363ace1d9..19b77624d6260 100644
--- a/docs/core-migration-guide.md
+++ b/docs/core-migration-guide.md
@@ -29,6 +29,7 @@ license: |
 - Since Spark 4.1, Spark uses Apache Hadoop Magic Committer for all S3 buckets by default. To restore the behavior before Spark 4.0, you can set `spark.hadoop.fs.s3a.committer.magic.enabled=false`.
 - Since Spark 4.1, `java.lang.InternalError` encountered during file reading will no longer fail the task if the configuration `spark.sql.files.ignoreCorruptFiles` or the data source option `ignoreCorruptFiles` is set to `true`. 
 - Since Spark 4.1, Spark ignores `*.blacklist.*` alternative configuration names. To restore the behavior before Spark 4.1, you can use the corresponding configuration names instead which exists since Spark 3.1.0.
+- Since Spark 4.1, Spark will use multiple threads for LZF compression to compress data in parallel. To restore the behavior before Spark 4.1, you can set `spark.io.compression.lzf.parallel.enabled` to `false`.
 
 ## Upgrading from Core 3.5 to 4.0