[SPARK-17243][WEB UI] Spark 2.0 History Server won't load with very large application history

## What changes were proposed in this pull request?

With the new History Server the summary page loads the application list via the the REST API, this makes it very slow to impossible to load with large (10K+) application history. This pr fixes this by adding the `spark.history.ui.maxApplications` conf to limit the number of applications the History Server displays. This is accomplished using a new optional `limit` param for the `applications` api. (Note this only applies to what the summary page displays, all the Application UI's are still accessible if the user knows the App ID and goes to the Application UI directly.)

I've also added a new test for the `limit` param in `HistoryServerSuite.scala`

## How was this patch tested?

Manual testing and dev/run-tests

Author: Alex Bozarth <ajbozart@us.ibm.com>

Closes #14835 from ajbozarth/spark17243.

core/src/main/resources/org/apache/spark/ui/static/historypage.js

@@ -15,6 +15,12 @@
  * limitations under the License.
  */
 
+var appLimit = -1;
+
+function setAppLimit(val) {
+    appLimit = val;
+}
+
 function makeIdNumeric(id) {
   var strs = id.split("_");
   if (strs.length < 3) {
@@ -89,7 +95,7 @@ $(document).ready(function() {
     requestedIncomplete = getParameterByName("showIncomplete", searchString);
     requestedIncomplete = (requestedIncomplete == "true" ? true : false);
 
-    $.getJSON("api/v1/applications", function(response,status,jqXHR) {
+    $.getJSON("api/v1/applications?limit=" + appLimit, function(response,status,jqXHR) {
       var array = [];
       var hasMultipleAttempts = false;
       for (i in response) {

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

@@ -45,7 +45,8 @@ private[history] class HistoryPage(parent: HistoryServer) extends WebUIPage("")
               <script src={UIUtils.prependBaseUri("/static/dataTables.rowsGroup.js")}></script> ++
                 <div id="history-summary" class="span12 pagination"></div> ++
                 <script src={UIUtils.prependBaseUri("/static/utils.js")}></script> ++
-                <script src={UIUtils.prependBaseUri("/static/historypage.js")}></script>
+                <script src={UIUtils.prependBaseUri("/static/historypage.js")}></script> ++
+                <script>setAppLimit({parent.maxApplications})</script>
             } else if (requestedIncomplete) {
               <h4>No incomplete applications found!</h4>
             } else {

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

@@ -28,6 +28,7 @@ import org.eclipse.jetty.servlet.{ServletContextHandler, ServletHolder}
 import org.apache.spark.{SecurityManager, SparkConf}
 import org.apache.spark.deploy.SparkHadoopUtil
 import org.apache.spark.internal.Logging
+import org.apache.spark.internal.config._
 import org.apache.spark.status.api.v1.{ApiRootResource, ApplicationInfo, ApplicationsListResource, UIRoot}
 import org.apache.spark.ui.{SparkUI, UIUtils, WebUI}
 import org.apache.spark.ui.JettyUtils._
@@ -55,6 +56,9 @@ class HistoryServer(
   // How many applications to retain
   private val retainedApplications = conf.getInt("spark.history.retainedApplications", 50)
 
+  // How many applications the summary ui displays
+  private[history] val maxApplications = conf.get(HISTORY_UI_MAX_APPS);
+
   // application
   private val appCache = new ApplicationCache(this, retainedApplications, new SystemClock())
 

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

@@ -120,6 +120,10 @@ package object config {
     .intConf
     .createWithDefault(100000)
 
+  // To limit how many applications are shown in the History Server summary ui
+  private[spark] val HISTORY_UI_MAX_APPS =
+    ConfigBuilder("spark.history.ui.maxApplications").intConf.createWithDefault(Integer.MAX_VALUE)
+
   private[spark] val IO_ENCRYPTION_ENABLED = ConfigBuilder("spark.io.encryption.enabled")
     .booleanConf
     .createWithDefault(false)

core/src/main/scala/org/apache/spark/status/api/v1/ApplicationListResource.scala

@@ -29,7 +29,8 @@ private[v1] class ApplicationListResource(uiRoot: UIRoot) {
   def appList(
       @QueryParam("status") status: JList[ApplicationStatus],
       @DefaultValue("2010-01-01") @QueryParam("minDate") minDate: SimpleDateParam,
-      @DefaultValue("3000-01-01") @QueryParam("maxDate") maxDate: SimpleDateParam)
+      @DefaultValue("3000-01-01") @QueryParam("maxDate") maxDate: SimpleDateParam,
+      @QueryParam("limit") limit: Integer)
   : Iterator[ApplicationInfo] = {
     val allApps = uiRoot.getApplicationInfoList
     val adjStatus = {
@@ -41,7 +42,7 @@ private[v1] class ApplicationListResource(uiRoot: UIRoot) {
     }
     val includeCompleted = adjStatus.contains(ApplicationStatus.COMPLETED)
     val includeRunning = adjStatus.contains(ApplicationStatus.RUNNING)
-    allApps.filter { app =>
+    val appList = allApps.filter { app =>
       val anyRunning = app.attempts.exists(!_.completed)
       // if any attempt is still running, we consider the app to also still be running
       val statusOk = (!anyRunning && includeCompleted) ||
@@ -53,6 +54,11 @@ private[v1] class ApplicationListResource(uiRoot: UIRoot) {
       }
       statusOk && dateOk
     }
+    if (limit != null) {
+      appList.take(limit)
+    } else {
+      appList
+    }
   }
 }
 

core/src/test/resources/HistoryServerExpectations/limit_app_list_json_expectation.json

+[ {
+  "id" : "local-1430917381534",
+  "name" : "Spark shell",
+  "attempts" : [ {
+    "startTime" : "2015-05-06T13:03:00.893GMT",
+    "endTime" : "2015-05-06T13:03:11.398GMT",
+    "lastUpdated" : "",
+    "duration" : 10505,
+    "sparkUser" : "irashid",
+    "completed" : true,
+    "startTimeEpoch" : 1430917380893,
+    "endTimeEpoch" : 1430917391398,
+    "lastUpdatedEpoch" : 0
+  } ]
+}, {
+  "id" : "local-1430917381535",
+  "name" : "Spark shell",
+  "attempts" : [ {
+    "attemptId" : "2",
+    "startTime" : "2015-05-06T13:03:00.893GMT",
+    "endTime" : "2015-05-06T13:03:00.950GMT",
+    "lastUpdated" : "",
+    "duration" : 57,
+    "sparkUser" : "irashid",
+    "completed" : true,
+    "startTimeEpoch" : 1430917380893,
+    "endTimeEpoch" : 1430917380950,
+    "lastUpdatedEpoch" : 0
+  }, {
+    "attemptId" : "1",
+    "startTime" : "2015-05-06T13:03:00.880GMT",
+    "endTime" : "2015-05-06T13:03:00.890GMT",
+    "lastUpdated" : "",
+    "duration" : 10,
+    "sparkUser" : "irashid",
+    "completed" : true,
+    "startTimeEpoch" : 1430917380880,
+    "endTimeEpoch" : 1430917380890,
+    "lastUpdatedEpoch" : 0
+  } ]
+}, {
+  "id" : "local-1426533911241",
+  "name" : "Spark shell",
+  "attempts" : [ {
+    "attemptId" : "2",
+    "startTime" : "2015-03-17T23:11:50.242GMT",
+    "endTime" : "2015-03-17T23:12:25.177GMT",
+    "lastUpdated" : "",
+    "duration" : 34935,
+    "sparkUser" : "irashid",
+    "completed" : true,
+    "startTimeEpoch" : 1426633910242,
+    "endTimeEpoch" : 1426633945177,
+    "lastUpdatedEpoch" : 0
+  }, {
+    "attemptId" : "1",
+    "startTime" : "2015-03-16T19:25:10.242GMT",
+    "endTime" : "2015-03-16T19:25:45.177GMT",
+    "lastUpdated" : "",
+    "duration" : 34935,
+    "sparkUser" : "irashid",
+    "completed" : true,
+    "startTimeEpoch" : 1426533910242,
+    "endTimeEpoch" : 1426533945177,
+    "lastUpdatedEpoch" : 0
+  } ]
+} ]

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

@@ -100,6 +100,7 @@ class HistoryServerSuite extends SparkFunSuite with BeforeAndAfter with Matchers
     "minDate app list json" -> "applications?minDate=2015-02-10",
     "maxDate app list json" -> "applications?maxDate=2015-02-10",
     "maxDate2 app list json" -> "applications?maxDate=2015-02-03T16:42:40.000GMT",
+    "limit app list json" -> "applications?limit=3",
     "one app json" -> "applications/local-1422981780767",
     "one app multi-attempt json" -> "applications/local-1426533911241",
     "job list json" -> "applications/local-1422981780767/jobs",

docs/monitoring.md

@@ -114,8 +114,17 @@ The history server can be configured as follows:
     <td>spark.history.retainedApplications</td>
     <td>50</td>
     <td>
-      The number of application UIs to retain. If this cap is exceeded, then the oldest
-      applications will be removed.
+      The number of applications to retain UI data for in the cache. If this cap is exceeded, then
+      the oldest applications will be removed from the cache. If an application is not in the cache,
+      it will have to be loaded from disk if its accessed from the UI.
+    </td>
+  </tr>
+  <tr>
+    <td>spark.history.ui.maxApplications</td>
+    <td>Int.MaxValue</td>
+    <td>
+      The number of applications to display on the history summary page. Application UIs are still
+      available by accessing their URLs directly even if they are not displayed on the history summary page.
     </td>
   </tr>
   <tr>
@@ -242,7 +251,8 @@ can be identified by their `[attempt-id]`. In the API listed below, when running
     <br>Examples:
     <br><code>?minDate=2015-02-10</code>
     <br><code>?minDate=2015-02-03T16:42:40.000GMT</code>
-    <br><code>?maxDate=[date]</code> latest date/time to list; uses same format as <code>minDate</code>.</td>
+    <br><code>?maxDate=[date]</code> latest date/time to list; uses same format as <code>minDate</code>.
+    <br><code>?limit=[limit]</code> limits the number of applications listed.</td>
   </tr>
   <tr>
     <td><code>/applications/[app-id]/jobs</code></td>