Address review comments

core/src/main/scala/org/apache/spark/SparkContext.scala

@@ -426,8 +426,7 @@ class SparkContext(config: SparkConf) extends Logging {
     _jars = Utils.getUserJars(_conf)
     _files = _conf.getOption(FILES.key).map(_.split(",")).map(_.filter(_.nonEmpty))
       .toSeq.flatten
-    _archives = _conf.getOption(ARCHIVES.key).map(_.split(",")).map(_.filter(_.nonEmpty))
-      .toSeq.flatten
+    _archives = _conf.getOption(ARCHIVES.key).map(Utils.stringToSeq).toSeq.flatten
 
     _eventLogDir =
       if (isEventLogEnabled) {
@@ -1638,10 +1637,11 @@ class SparkContext(config: SparkConf) extends Logging {
       val uriToDownload = UriBuilder.fromUri(new URI(key)).fragment(null).build()
       val source = Utils.fetchFile(uriToDownload.toString, Utils.createTempDir(), conf,
         env.securityManager, hadoopConfiguration, timestamp, useCache = false, shouldUntar = false)
-      logInfo(s"Unpacking an archive $path")
       val dest = new File(
         SparkFiles.getRootDirectory(),
         if (uri.getFragment != null) uri.getFragment else source.getName)
+      logInfo(
+        s"Unpacking an archive $path from ${source.getAbsolutePath} to ${dest.getAbsolutePath}")
       Utils.deleteRecursively(dest)
       Utils.unpack(source, dest)
       postEnvironmentUpdate()

core/src/main/scala/org/apache/spark/deploy/SparkSubmitArguments.scala

@@ -513,7 +513,7 @@ private[deploy] class SparkSubmitArguments(args: Seq[String], env: Map[String, S
         |  --files FILES               Comma-separated list of files to be placed in the working
         |                              directory of each executor. File paths of these files
         |                              in executors can be accessed via SparkFiles.get(fileName).
-        |  --archives ARCHIVES         Comma separated list of archives to be extracted into the
+        |  --archives ARCHIVES         Comma-separated list of archives to be extracted into the
         |                              working directory of each executor.
         |
         |  --conf, -c PROP=VALUE       Arbitrary Spark configuration property.

core/src/main/scala/org/apache/spark/executor/Executor.scala

@@ -233,7 +233,7 @@ private[spark] class Executor(
 
   // To allow users to distribute plugins and their required files
   // specified by --jars, --files and --archives on application submission, those
-  // jars/files/archives should be downloaded and added to the class loader vi
+  // jars/files/archives should be downloaded and added to the class loader via
   // updateDependencies. This should be done before plugin initialization below
   // because executors search plugins from the class loader and initialize them.
   private val Seq(initialUserJars, initialUserFiles, initialUserArchives) =
@@ -930,11 +930,12 @@ private[spark] class Executor(
         val sourceURI = new URI(name)
         val uriToDownload = UriBuilder.fromUri(sourceURI).fragment(null).build()
         val source = Utils.fetchFile(uriToDownload.toString, Utils.createTempDir(), conf,
-          env.securityManager, hadoopConf, timestamp, useCache = false, shouldUntar = false)
-        logInfo(s"Unpacking an archive $name")
+          env.securityManager, hadoopConf, timestamp, useCache = !isLocal, shouldUntar = false)
         val dest = new File(
           SparkFiles.getRootDirectory(),
           if (sourceURI.getFragment != null) sourceURI.getFragment else source.getName)
+        logInfo(
+          s"Unpacking an archive $name from ${source.getAbsolutePath} to ${dest.getAbsolutePath}")
         Utils.deleteRecursively(dest)
         Utils.unpack(source, dest)
         currentArchives(name) = timestamp

core/src/main/scala/org/apache/spark/internal/config/package.scala

@@ -1805,7 +1805,7 @@ package object config {
 
   private[spark] val ARCHIVES = ConfigBuilder("spark.archives")
     .version("3.1.0")
-    .doc("Comma separated list of archives to be extracted into the working directory of each " +
+    .doc("Comma-separated list of archives to be extracted into the working directory of each " +
       "executor. .jar, .tar.gz, .tgz and .zip are supported. You can specify the directory " +
       "name to unpack via adding '#' after the file name to unpack, for example, " +
       "'file.zip#directory'. This configuration is experimental.")

core/src/main/scala/org/apache/spark/util/Utils.scala

@@ -487,6 +487,10 @@ private[spark] object Utils extends Logging {
    *
    * Throws SparkException if the target file already exists and has different contents than
    * the requested file.
+   *
+   * If `shouldUntar` is true, it untars the given url if it is a tar.gz or tgz into `targetDir`.
+   * This is a legacy behavior, and users should better use `spark.archives` configuration or
+   * `SparkContext.addArchive`
    */
   def fetchFile(
       url: String,

docs/configuration.md

@@ -788,7 +788,7 @@ Apart from these, the following properties are also available, and may be useful
   <td><code>spark.archives</code></td>
   <td></td>
   <td>
-    Comma separated list of archives to be extracted into the working directory of each executor.
+    Comma-separated list of archives to be extracted into the working directory of each executor.
     .jar, .tar.gz, .tgz and .zip are supported. You can specify the directory name to unpack via
     adding <code>#</code> after the file name to unpack, for example, <code>file.zip#directory</code>.
     This configuration is experimental.