diff --git a/core/src/test/scala/org/apache/spark/deploy/history/HistoryServerSuite.scala b/core/src/test/scala/org/apache/spark/deploy/history/HistoryServerSuite.scala
index 02a32a80ddd7..1aa846b3ac43 100644
--- a/core/src/test/scala/org/apache/spark/deploy/history/HistoryServerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/deploy/history/HistoryServerSuite.scala
@@ -74,6 +74,7 @@ abstract class HistoryServerSuite extends SparkFunSuite with BeforeAndAfter with
 
   private var provider: FsHistoryProvider = null
   private var server: HistoryServer = null
+  private val localhost: String = Utils.localCanonicalHostName()
   private var port: Int = -1
 
   protected def diskBackend: HybridStoreDiskBackend.Value
@@ -428,12 +429,12 @@ abstract class HistoryServerSuite extends SparkFunSuite with BeforeAndAfter with
 
     // build a URL for an app or app/attempt plus a page underneath
     def buildURL(appId: String, suffix: String): URL = {
-      new URL(s"http://localhost:$port/history/$appId$suffix")
+      new URL(s"http://$localhost:$port/history/$appId$suffix")
     }
 
     // build a rest URL for the application and suffix.
     def applications(appId: String, suffix: String): URL = {
-      new URL(s"http://localhost:$port/api/v1/applications/$appId$suffix")
+      new URL(s"http://$localhost:$port/api/v1/applications/$appId$suffix")
     }
 
     // start initial job
@@ -586,11 +587,11 @@ abstract class HistoryServerSuite extends SparkFunSuite with BeforeAndAfter with
 
     val port = server.boundPort
     val testUrls = Seq(
-      s"http://localhost:$port/api/v1/applications/$appId/1/jobs",
-      s"http://localhost:$port/history/$appId/1/jobs/",
-      s"http://localhost:$port/api/v1/applications/$appId/logs",
-      s"http://localhost:$port/api/v1/applications/$appId/1/logs",
-      s"http://localhost:$port/api/v1/applications/$appId/2/logs")
+      s"http://$localhost:$port/api/v1/applications/$appId/1/jobs",
+      s"http://$localhost:$port/history/$appId/1/jobs/",
+      s"http://$localhost:$port/api/v1/applications/$appId/logs",
+      s"http://$localhost:$port/api/v1/applications/$appId/1/logs",
+      s"http://$localhost:$port/api/v1/applications/$appId/2/logs")
 
     tests.foreach { case (user, expectedCode) =>
       testUrls.foreach { url =>
@@ -609,9 +610,9 @@ abstract class HistoryServerSuite extends SparkFunSuite with BeforeAndAfter with
 
     val port = server.boundPort
     val testUrls = Seq(
-      s"http://localhost:$port/api/v1/applications/$appId/logs",
-      s"http://localhost:$port/api/v1/applications/$appId/1/logs",
-      s"http://localhost:$port/api/v1/applications/$appId/2/logs")
+      s"http://$localhost:$port/api/v1/applications/$appId/logs",
+      s"http://$localhost:$port/api/v1/applications/$appId/1/logs",
+      s"http://$localhost:$port/api/v1/applications/$appId/2/logs")
 
     testUrls.foreach { url =>
       TestUtils.httpResponseCode(new URL(url))
@@ -636,9 +637,9 @@ abstract class HistoryServerSuite extends SparkFunSuite with BeforeAndAfter with
     def buildPageAttemptUrl(appId: String, attemptId: Option[Int]): URL = {
       attemptId match {
         case Some(id) =>
-          new URL(s"http://localhost:$port/history/$appId/$id")
+          new URL(s"http://$localhost:$port/history/$appId/$id")
         case None =>
-          new URL(s"http://localhost:$port/history/$appId")
+          new URL(s"http://$localhost:$port/history/$appId")
       }
     }
 
@@ -663,7 +664,7 @@ abstract class HistoryServerSuite extends SparkFunSuite with BeforeAndAfter with
   }
 
   def getContentAndCode(path: String, port: Int = port): (Int, Option[String], Option[String]) = {
-    HistoryServerSuite.getContentAndCode(new URL(s"http://localhost:$port/api/v1/$path"))
+    HistoryServerSuite.getContentAndCode(new URL(s"http://$localhost:$port/api/v1/$path"))
   }
 
   def getUrl(path: String): String = {
@@ -671,7 +672,7 @@ abstract class HistoryServerSuite extends SparkFunSuite with BeforeAndAfter with
   }
 
   def generateURL(path: String): URL = {
-    new URL(s"http://localhost:$port/api/v1/$path")
+    new URL(s"http://$localhost:$port/api/v1/$path")
   }
 
   def generateExpectation(name: String, path: String): Unit = {
@@ -686,7 +687,7 @@ abstract class HistoryServerSuite extends SparkFunSuite with BeforeAndAfter with
   test("SPARK-31697: HistoryServer should set Content-Type") {
     val port = server.boundPort
     val nonExistenceAppId = "local-non-existence"
-    val url = new URL(s"http://localhost:$port/history/$nonExistenceAppId")
+    val url = new URL(s"http://$localhost:$port/history/$nonExistenceAppId")
     val conn = url.openConnection().asInstanceOf[HttpURLConnection]
     conn.setRequestMethod("GET")
     conn.connect()
@@ -697,7 +698,7 @@ abstract class HistoryServerSuite extends SparkFunSuite with BeforeAndAfter with
 
   test("Redirect to the root page when accessed to /history/") {
     val port = server.boundPort
-    val url = new URL(s"http://localhost:$port/history/")
+    val url = new URL(s"http://$localhost:$port/history/")
     val conn = url.openConnection().asInstanceOf[HttpURLConnection]
     conn.setRequestMethod("GET")
     conn.setUseCaches(false)
@@ -705,7 +706,7 @@ abstract class HistoryServerSuite extends SparkFunSuite with BeforeAndAfter with
     conn.setInstanceFollowRedirects(false)
     conn.connect()
     assert(conn.getResponseCode === 302)
-    assert(conn.getHeaderField("Location") === s"http://localhost:$port/")
+    assert(conn.getHeaderField("Location") === s"http://$localhost:$port/")
   }
 }
 
diff --git a/core/src/test/scala/org/apache/spark/deploy/master/MasterSuite.scala b/core/src/test/scala/org/apache/spark/deploy/master/MasterSuite.scala
index 3832e382a70f..1fac3522aed5 100644
--- a/core/src/test/scala/org/apache/spark/deploy/master/MasterSuite.scala
+++ b/core/src/test/scala/org/apache/spark/deploy/master/MasterSuite.scala
@@ -325,9 +325,9 @@ class MasterSuite extends SparkFunSuite
     val conf = new SparkConf()
     val localCluster = LocalSparkCluster(2, 2, 512, conf)
     localCluster.start()
-    val masterUrl = s"http://localhost:${localCluster.masterWebUIPort}"
+    val masterUrl = s"http://${Utils.localCanonicalHostName()}:${localCluster.masterWebUIPort}"
     try {
-      eventually(timeout(5.seconds), interval(100.milliseconds)) {
+      eventually(timeout(50.seconds), interval(100.milliseconds)) {
         val json = Utils
           .tryWithResource(Source.fromURL(s"$masterUrl/json"))(_.getLines().mkString("\n"))
         val JArray(workers) = (parse(json) \ "workers")
@@ -362,9 +362,9 @@ class MasterSuite extends SparkFunSuite
     conf.set(UI_REVERSE_PROXY, true)
     val localCluster = LocalSparkCluster(2, 2, 512, conf)
     localCluster.start()
-    val masterUrl = s"http://localhost:${localCluster.masterWebUIPort}"
+    val masterUrl = s"http://${Utils.localCanonicalHostName()}:${localCluster.masterWebUIPort}"
     try {
-      eventually(timeout(5.seconds), interval(100.milliseconds)) {
+      eventually(timeout(50.seconds), interval(100.milliseconds)) {
         val json = Utils
           .tryWithResource(Source.fromURL(s"$masterUrl/json"))(_.getLines().mkString("\n"))
         val JArray(workers) = (parse(json) \ "workers")
@@ -400,9 +400,9 @@ class MasterSuite extends SparkFunSuite
     conf.set(UI_REVERSE_PROXY_URL, reverseProxyUrl)
     val localCluster = LocalSparkCluster(2, 2, 512, conf)
     localCluster.start()
-    val masterUrl = s"http://localhost:${localCluster.masterWebUIPort}"
+    val masterUrl = s"http://${Utils.localCanonicalHostName()}:${localCluster.masterWebUIPort}"
     try {
-      eventually(timeout(5.seconds), interval(100.milliseconds)) {
+      eventually(timeout(50.seconds), interval(100.milliseconds)) {
         val json = Utils
           .tryWithResource(Source.fromURL(s"$masterUrl/json"))(_.getLines().mkString("\n"))
         val JArray(workers) = (parse(json) \ "workers")
diff --git a/core/src/test/scala/org/apache/spark/deploy/master/ui/MasterWebUISuite.scala b/core/src/test/scala/org/apache/spark/deploy/master/ui/MasterWebUISuite.scala
index be83ec12f92f..253517fdcf94 100644
--- a/core/src/test/scala/org/apache/spark/deploy/master/ui/MasterWebUISuite.scala
+++ b/core/src/test/scala/org/apache/spark/deploy/master/ui/MasterWebUISuite.scala
@@ -32,6 +32,7 @@ import org.apache.spark.deploy.DeployMessages.{DecommissionWorkersOnHosts, KillD
 import org.apache.spark.deploy.DeployTestUtils._
 import org.apache.spark.deploy.master._
 import org.apache.spark.rpc.{RpcEndpointRef, RpcEnv}
+import org.apache.spark.util.Utils
 
 
 class MasterWebUISuite extends SparkFunSuite with BeforeAndAfterAll {
@@ -68,7 +69,7 @@ class MasterWebUISuite extends SparkFunSuite with BeforeAndAfterAll {
 
     when(master.idToApp).thenReturn(HashMap[String, ApplicationInfo]((activeApp.id, activeApp)))
 
-    val url = s"http://localhost:${masterWebUI.boundPort}/app/kill/"
+    val url = s"http://${Utils.localCanonicalHostName()}:${masterWebUI.boundPort}/app/kill/"
     val body = convPostDataToString(Map(("id", activeApp.id), ("terminate", "true")))
     val conn = sendHttpRequest(url, "POST", body)
     conn.getResponseCode
@@ -79,7 +80,7 @@ class MasterWebUISuite extends SparkFunSuite with BeforeAndAfterAll {
 
   test("kill driver") {
     val activeDriverId = "driver-0"
-    val url = s"http://localhost:${masterWebUI.boundPort}/driver/kill/"
+    val url = s"http://${Utils.localCanonicalHostName()}:${masterWebUI.boundPort}/driver/kill/"
     val body = convPostDataToString(Map(("id", activeDriverId), ("terminate", "true")))
     val conn = sendHttpRequest(url, "POST", body)
     conn.getResponseCode
@@ -89,7 +90,7 @@ class MasterWebUISuite extends SparkFunSuite with BeforeAndAfterAll {
   }
 
   private def testKillWorkers(hostnames: Seq[String]): Unit = {
-    val url = s"http://localhost:${masterWebUI.boundPort}/workers/kill/"
+    val url = s"http://${Utils.localCanonicalHostName()}:${masterWebUI.boundPort}/workers/kill/"
     val body = convPostDataToString(hostnames.map(("host", _)))
     val conn = sendHttpRequest(url, "POST", body)
     // The master is mocked here, so cannot assert on the response code
@@ -99,7 +100,7 @@ class MasterWebUISuite extends SparkFunSuite with BeforeAndAfterAll {
   }
 
   test("Kill one host") {
-    testKillWorkers(Seq("localhost"))
+    testKillWorkers(Seq("${Utils.localCanonicalHostName()}"))
   }
 
   test("Kill multiple hosts") {