[SPARK-49128][CORE] Support custom History Server UI title

core/src/main/scala/org/apache/spark/deploy/history/HistoryPage.scala

@@ -105,7 +105,7 @@ private[history] class HistoryPage(parent: HistoryServer) extends WebUIPage("")
       <script type="module" src={UIUtils.prependBaseUri(
         request, "/static/utils.js")}></script> ++
       summary ++ appList ++ pageLink
-    UIUtils.basicSparkPage(request, content, "History Server", true)
+    UIUtils.basicSparkPage(request, content, parent.title, true)
   }
 
   def shouldDisplayApplications(requestedIncomplete: Boolean): Boolean = {

core/src/main/scala/org/apache/spark/deploy/history/HistoryServer.scala

@@ -61,6 +61,8 @@ class HistoryServer(
     poolSize = 1000)
   with Logging with UIRoot with ApplicationCacheOperations {
 
+  val title = conf.get(History.HISTORY_SERVER_UI_TITLE)
+
   // How many applications to retain
   private val retainedApplications = conf.get(History.RETAINED_APPLICATIONS)
 

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

@@ -109,6 +109,12 @@ private[spark] object History {
     .bytesConf(ByteUnit.BYTE)
     .createWithDefaultString("10g")
 
+  val HISTORY_SERVER_UI_TITLE = ConfigBuilder("spark.history.ui.title")
+    .version("4.0.0")
+    .doc("Specifies the title of the History Server UI page.")
+    .stringConf
+    .createWithDefault("History Server")
+
   val HISTORY_SERVER_UI_PORT = ConfigBuilder("spark.history.ui.port")
     .doc("Web UI port to bind Spark History Server")
     .version("1.0.0")

core/src/test/scala/org/apache/spark/deploy/history/HistoryServerPageSuite.scala

@@ -43,12 +43,13 @@ class HistoryServerPageSuite extends SparkFunSuite with BeforeAndAfter {
   private val localhost: String = Utils.localHostNameForURI()
   private var port: Int = -1
 
-  private def startHistoryServer(logDir: String): Unit = {
+  private def startHistoryServer(logDir: String, title: Option[String] = None): Unit = {
     assert(server.isEmpty)
     val conf = new SparkConf()
       .set(HISTORY_LOG_DIR, logDir)
       .set(UPDATE_INTERVAL_S.key, "0")
       .set(IS_TESTING, true)
+    title.foreach(conf.set(HISTORY_SERVER_UI_TITLE.key, _))
     val provider = new FsHistoryProvider(conf)
     provider.checkForLogs()
     val securityManager = HistoryServer.createSecurityManager(conf)
@@ -100,4 +101,19 @@ class HistoryServerPageSuite extends SparkFunSuite with BeforeAndAfter {
       stopHistoryServer()
     }
   }
+
+  test("SPARK-49128: Support custom History Server UI title") {
+    Seq(None, Some("Custom History Server Title")).foreach { title =>
+      startHistoryServer(logDirs.head, title)
+      val page = new HistoryPage(server.get)
+      val (code, htmlOpt, errOpt) = HistoryServerSuite.getContentAndCode(
+        new URL(s"http://$localhost:$port/")
+      )
+      assert(code == HttpServletResponse.SC_OK)
+      val expected = title.getOrElse("History Server")
+      assert(htmlOpt.isDefined && htmlOpt.get.contains(s"<title>$expected</title>"))
+      assert(errOpt.isEmpty)
+      stopHistoryServer()
+    }
+  }
 }