YARN-9221. Added flag to disable dynamic auxiliary service feature.

            Contributed by Billie Rinaldi

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/site/markdown/PluggableShuffleAndPluggableSort.md

@@ -65,7 +65,7 @@ The collector class configuration may specify a comma-separated list of collecto
 
 There are two ways to configure auxiliary services, through a manifest file or through the Configuration (the old way). If a manifest file is used, auxiliary service configurations are not read from the Configuration.
 
-If using a manifest file, the file name can be set in *yarn-site.xml* under the property `yarn.nodemanager.aux-services.manifest`, or the file may be sent to the NM via a PUT call to the endpoint `http://nm-http-address:port/ws/v1/node/auxiliaryservices`. If the file name is set in the Configuration, NMs will check this file for new modifications at an interval specified by `yarn.nodemanager.aux-services.manifest.reload-ms` (defaults to 2 minutes; setting interval <= 0 means it will not be reloaded automatically).
+If using a manifest, the feature must be enabled by setting the property `yarn.nodemanager.aux-services.manifest.enabled` to true in *yarn-site.xml*. The file path can be set in *yarn-site.xml* under the property `yarn.nodemanager.aux-services.manifest`, or the file may be sent to each NM via a PUT call to the endpoint `http://nm-http-address:port/ws/v1/node/auxiliaryservices`. If the file path is set in the Configuration, NMs will check this file for new modifications at an interval specified by `yarn.nodemanager.aux-services.manifest.reload-ms` (defaults to 0; setting interval <= 0 means it will not be reloaded automatically).
 
 Otherwise, set the following properties to configure aux services through the Configuration.
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java

@@ -2227,13 +2227,34 @@ public class YarnConfiguration extends Configuration {
   public static final String NM_AUX_SERVICES = 
       NM_PREFIX + "aux-services";
 
+  /**
+   * Boolean indicating whether loading aux services from a manifest is
+   * enabled. If enabled, aux services may be dynamically modified through
+   * reloading the manifest via filesystem changes or a REST API. When
+   * enabled, aux services configuration properties unrelated to the manifest
+   * will be ignored.
+   */
+  public static final String NM_AUX_SERVICES_MANIFEST_ENABLED =
+      NM_AUX_SERVICES + ".manifest.enabled";
+
+  public static final boolean DEFAULT_NM_AUX_SERVICES_MANIFEST_ENABLED =
+      false;
+
+  /**
+   * File containing auxiliary service specifications.
+   */
   public static final String NM_AUX_SERVICES_MANIFEST =
       NM_AUX_SERVICES + ".manifest";
 
+  /**
+   * Interval at which manifest file will be reloaded when modifications are
+   * found (0 or less means that the file will not be checked for modifications
+   * and reloaded).
+   */
   public static final String NM_AUX_SERVICES_MANIFEST_RELOAD_MS =
       NM_AUX_SERVICES + ".manifest.reload-ms";
 
-  public static final long DEFAULT_NM_AUX_SERVICES_MANIFEST_RELOAD_MS = 120000;
+  public static final long DEFAULT_NM_AUX_SERVICES_MANIFEST_RELOAD_MS = 0;
 
   public static final String NM_AUX_SERVICE_FMT =
       NM_PREFIX + "aux-services.%s.class";

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml

@@ -1922,9 +1922,17 @@
   </property>
 
   <property>
-    <description>A file containing auxiliary service specifications. If
-      manifest file is specified, yarn.nodemanager.aux-services and other
-      aux services configuration properties will be ignored.</description>
+    <description>Boolean indicating whether loading aux services from a manifest
+      is enabled. If enabled, aux services may be dynamically modified through
+      reloading the manifest via filesystem changes or a REST API. When
+      enabled, aux services configuration properties unrelated to the manifest
+      will be ignored.</description>
+    <name>yarn.nodemanager.aux-services.manifest.enabled</name>
+    <value>false</value>
+  </property>
+
+  <property>
+    <description>A file containing auxiliary service specifications.</description>
     <name>yarn.nodemanager.aux-services.manifest</name>
     <value></value>
   </property>
@@ -1933,7 +1941,7 @@
     <description>Length of time in ms to wait between reloading aux services
       manifest. If 0 or less, manifest will not be reloaded.</description>
     <name>yarn.nodemanager.aux-services.manifest.reload-ms</name>
-    <value></value>
+    <value>0</value>
   </property>
 
   <property>

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/AuxServices.java

@@ -110,8 +110,9 @@ public class AuxServices extends AbstractService
   private Path stateStoreRoot = null;
   private FileSystem stateStoreFs = null;
 
-  private Path manifest;
-  private FileSystem manifestFS;
+  private volatile boolean manifestEnabled = false;
+  private volatile Path manifest;
+  private volatile FileSystem manifestFS;
   private Timer manifestReloadTimer;
   private TimerTask manifestReloadTask;
   private long manifestReloadInterval;
@@ -139,6 +140,13 @@ public class AuxServices extends AbstractService
     // Obtain services from configuration in init()
   }
 
+  /**
+   * Returns whether aux services manifest / dynamic loading is enabled.
+   */
+  public boolean isManifestEnabled() {
+    return manifestEnabled;
+  }
+
   /**
    * Adds a service to the service map.
    *
@@ -480,7 +488,8 @@ public class AuxServices extends AbstractService
    *
    * @throws IOException if manifest can't be loaded
    */
-  private void reloadManifest() throws IOException {
+  @VisibleForTesting
+  protected void reloadManifest() throws IOException {
     loadManifest(getConfig(), true);
   }
 
@@ -488,9 +497,15 @@ public class AuxServices extends AbstractService
    * Reloads auxiliary services. Must be called after service init.
    *
    * @param services a list of auxiliary services
-   * @throws IOException if aux services have not been started yet
+   * @throws IOException if aux services have not been started yet or dynamic
+   * reloading is not enabled
    */
-  public void reload(AuxServiceRecords services) throws IOException {
+  public synchronized void reload(AuxServiceRecords services) throws
+      IOException {
+    if (!manifestEnabled) {
+      throw new IOException("Dynamic reloading is not enabled via " +
+          YarnConfiguration.NM_AUX_SERVICES_MANIFEST_ENABLED);
+    }
     if (getServiceState() != Service.STATE.STARTED) {
       throw new IOException("Auxiliary services have not been started yet, " +
           "please retry later");
@@ -578,6 +593,10 @@ public class AuxServices extends AbstractService
   @VisibleForTesting
   protected synchronized void loadManifest(Configuration conf, boolean
       startServices) throws IOException {
+    if (!manifestEnabled) {
+      throw new IOException("Dynamic reloading is not enabled via " +
+          YarnConfiguration.NM_AUX_SERVICES_MANIFEST_ENABLED);
+    }
     if (manifest == null) {
       return;
     }
@@ -730,8 +749,10 @@ public class AuxServices extends AbstractService
           STATE_STORE_ROOT_NAME);
       stateStoreFs = FileSystem.getLocal(conf);
     }
-    String manifestStr = conf.get(YarnConfiguration.NM_AUX_SERVICES_MANIFEST);
-    if (manifestStr == null) {
+    manifestEnabled = conf.getBoolean(
+        YarnConfiguration.NM_AUX_SERVICES_MANIFEST_ENABLED,
+        YarnConfiguration.DEFAULT_NM_AUX_SERVICES_MANIFEST_ENABLED);
+    if (!manifestEnabled) {
       Collection<String> auxNames = conf.getStringCollection(
           YarnConfiguration.NM_AUX_SERVICES);
       for (final String sName : auxNames) {
@@ -742,14 +763,20 @@ public class AuxServices extends AbstractService
         addService(sName, s, service);
       }
     } else {
-      manifest = new Path(manifestStr);
-      manifestFS = FileSystem.get(new URI(manifestStr), conf);
-      loadManifest(conf, false);
+      String manifestStr = conf.get(YarnConfiguration.NM_AUX_SERVICES_MANIFEST);
+      if (manifestStr != null) {
+        manifest = new Path(manifestStr);
+        manifestFS = FileSystem.get(new URI(manifestStr), conf);
+        loadManifest(conf, false);
+        manifestReloadInterval = conf.getLong(
+            YarnConfiguration.NM_AUX_SERVICES_MANIFEST_RELOAD_MS,
+            YarnConfiguration.DEFAULT_NM_AUX_SERVICES_MANIFEST_RELOAD_MS);
+        manifestReloadTask = new ManifestReloadTask();
+      } else {
+        LOG.info("Auxiliary services manifest is enabled, but no manifest " +
+            "file is specified in the configuration.");
+      }
     }
-    manifestReloadInterval = conf.getLong(
-        YarnConfiguration.NM_AUX_SERVICES_MANIFEST_RELOAD_MS,
-        YarnConfiguration.DEFAULT_NM_AUX_SERVICES_MANIFEST_RELOAD_MS);
-    manifestReloadTask = new ManifestReloadTask();
 
     super.serviceInit(conf);
   }
@@ -781,8 +808,10 @@ public class AuxServices extends AbstractService
       String name = entry.getKey();
       startAuxService(name, service, serviceRecordMap.get(name));
     }
-    if (manifest != null && manifestReloadInterval > 0) {
-      manifestReloadTimer = new Timer("AuxServicesManifestRelaod-Timer",
+    if (manifestEnabled && manifest != null && manifestReloadInterval > 0) {
+      LOG.info("Scheduling reloading auxiliary services manifest file at " +
+          "interval " + manifestReloadInterval + " ms");
+      manifestReloadTimer = new Timer("AuxServicesManifestReload-Timer",
           true);
       manifestReloadTimer.schedule(manifestReloadTask,
           manifestReloadInterval, manifestReloadInterval);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/webapp/NMWebServices.java

@@ -567,6 +567,10 @@ public class NMWebServices {
   public AuxiliaryServicesInfo getAuxiliaryServices(@javax.ws.rs.core.Context
       HttpServletRequest hsr) {
     init();
+    if (!this.nmContext.getAuxServices().isManifestEnabled()) {
+      throw new BadRequestException("Auxiliary services manifest is not " +
+          "enabled");
+    }
     AuxiliaryServicesInfo auxiliaryServices = new AuxiliaryServicesInfo();
     Collection<AuxServiceRecord> loadedServices = nmContext.getAuxServices()
         .getServiceRecords();
@@ -582,6 +586,11 @@ public class NMWebServices {
       MediaType.APPLICATION_XML + "; " + JettyUtils.UTF_8 })
   public Response putAuxiliaryServices(@javax.ws.rs.core.Context
       HttpServletRequest req, AuxServiceRecords services) {
+    init();
+    if (!this.nmContext.getAuxServices().isManifestEnabled()) {
+      throw new BadRequestException("Auxiliary services manifest is not " +
+          "enabled");
+    }
     if (!hasAdminAccess(req)) {
       return Response.status(Status.FORBIDDEN).build();
     }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/TestAuxServices.java

@@ -252,6 +252,7 @@ public class TestAuxServices {
 
   private void writeManifestFile(AuxServiceRecords services, Configuration
       conf) throws IOException {
+    conf.setBoolean(YarnConfiguration.NM_AUX_SERVICES_MANIFEST_ENABLED, true);
     conf.set(YarnConfiguration.NM_AUX_SERVICES_MANIFEST, manifest
         .getAbsolutePath());
     mapper.writeValue(manifest, services);
@@ -901,6 +902,7 @@ public class TestAuxServices {
 
   @Test
   public void testManualReload() throws IOException {
+    Assume.assumeTrue(useManifest);
     Configuration conf = getABConf();
     final AuxServices aux = new AuxServices(MOCK_AUX_PATH_HANDLER,
         MOCK_CONTEXT, MOCK_DEL_SERVICE);
@@ -921,4 +923,28 @@ public class TestAuxServices {
     assertEquals(0, aux.getServices().size());
     aux.stop();
   }
+
+  @Test
+  public void testReloadWhenDisabled() throws IOException {
+    Configuration conf = new Configuration();
+    final AuxServices aux = new AuxServices(MOCK_AUX_PATH_HANDLER,
+        MOCK_CONTEXT, MOCK_DEL_SERVICE);
+    aux.init(conf);
+    try {
+      aux.reload(null);
+      Assert.fail("Should receive the exception.");
+    } catch (IOException e) {
+      assertTrue("Wrong message: " + e.getMessage(),
+          e.getMessage().equals("Dynamic reloading is not enabled via " +
+              YarnConfiguration.NM_AUX_SERVICES_MANIFEST_ENABLED));
+    }
+    try {
+      aux.reloadManifest();
+      Assert.fail("Should receive the exception.");
+    } catch (IOException e) {
+      assertTrue("Wrong message: " + e.getMessage(),
+          e.getMessage().equals("Dynamic reloading is not enabled via " +
+              YarnConfiguration.NM_AUX_SERVICES_MANIFEST_ENABLED));
+    }
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/webapp/TestNMWebServicesAuxServices.java

@@ -18,7 +18,9 @@
 
 package org.apache.hadoop.yarn.server.nodemanager.webapp;
 
+import static org.apache.hadoop.yarn.webapp.WebServicesTestUtils.assertResponseStatusCode;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -33,6 +35,7 @@ import javax.ws.rs.core.MediaType;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 
+import com.sun.jersey.api.client.UniformInterfaceException;
 import com.sun.jersey.api.client.filter.LoggingFilter;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileUtil;
@@ -54,6 +57,7 @@ import org.apache.hadoop.yarn.webapp.JerseyTestBase;
 import org.apache.hadoop.yarn.webapp.WebApp;
 import org.apache.hadoop.yarn.webapp.WebServicesTestUtils;
 import org.codehaus.jettison.json.JSONArray;
+import org.codehaus.jettison.json.JSONException;
 import org.codehaus.jettison.json.JSONObject;
 import org.junit.AfterClass;
 import org.junit.Before;
@@ -195,6 +199,7 @@ public class TestNMWebServicesAuxServices extends JerseyTestBase {
   private void addAuxServices(AuxServiceRecord... records) {
     AuxServices auxServices = mock(AuxServices.class);
     when(auxServices.getServiceRecords()).thenReturn(Arrays.asList(records));
+    when(auxServices.isManifestEnabled()).thenReturn(true);
     nmContext.setAuxServices(auxServices);
   }
 
@@ -238,7 +243,7 @@ public class TestNMWebServicesAuxServices extends JerseyTestBase {
   }
 
   @Test
-  public void testNodeContainerXML() throws Exception {
+  public void testNodeAuxServicesXML() throws Exception {
     AuxServiceRecord r1 = new AuxServiceRecord().name("name1").launchTime(new
         Date(123L)).version("1");
     AuxServiceRecord r2 = new AuxServiceRecord().name("name2").launchTime(new
@@ -259,10 +264,43 @@ public class TestNMWebServicesAuxServices extends JerseyTestBase {
     Document dom = db.parse(is);
     NodeList nodes = dom.getElementsByTagName("service");
     assertEquals("incorrect number of elements", 2, nodes.getLength());
-    verifyContainersInfoXML(nodes, r1, r2);
+    verifyAuxServicesInfoXML(nodes, r1, r2);
   }
 
-  public void verifyContainersInfoXML(NodeList nodes, AuxServiceRecord...
+  @Test
+  public void testAuxServicesDisabled() throws JSONException, Exception {
+    AuxServices auxServices = mock(AuxServices.class);
+    when(auxServices.isManifestEnabled()).thenReturn(false);
+    nmContext.setAuxServices(auxServices);
+    WebResource r = resource();
+    try {
+      r.path("ws").path("v1").path("node").path(AUX_SERVICES_PATH)
+          .accept(MediaType.APPLICATION_JSON).get(JSONObject.class);
+      fail("should have thrown exception on invalid user query");
+    } catch (UniformInterfaceException ue) {
+      ClientResponse response = ue.getResponse();
+      assertResponseStatusCode(ClientResponse.Status.BAD_REQUEST,
+          response.getStatusInfo());
+      assertEquals(MediaType.APPLICATION_JSON_TYPE + "; " + JettyUtils.UTF_8,
+          response.getType().toString());
+      JSONObject msg = response.getEntity(JSONObject.class);
+      JSONObject exception = msg.getJSONObject("RemoteException");
+      assertEquals("incorrect number of elements", 3, exception.length());
+      String message = exception.getString("message");
+      String type = exception.getString("exception");
+      String classname = exception.getString("javaClassName");
+      WebServicesTestUtils.checkStringMatch(
+          "exception message",
+          "java.lang.Exception: Auxiliary services manifest is not enabled",
+          message);
+      WebServicesTestUtils.checkStringMatch("exception type",
+          "BadRequestException", type);
+      WebServicesTestUtils.checkStringMatch("exception classname",
+          "org.apache.hadoop.yarn.webapp.BadRequestException", classname);
+    }
+  }
+
+  public void verifyAuxServicesInfoXML(NodeList nodes, AuxServiceRecord...
       records) {
     for (int i = 0; i < nodes.getLength(); i++) {
       Element element = (Element) nodes.item(i);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/NodeManager.md

@@ -95,7 +95,7 @@ Step 5.  Auxiliary services.
 
   * A simple example for the above is the auxiliary service 'ShuffleHandler' for MapReduce (MR). ShuffleHandler respects the above two requirements already, so users/admins don't have to do anything for it to support NM restart: (1) The configuration property **mapreduce.shuffle.port** controls which port the ShuffleHandler on a NodeManager host binds to, and it defaults to a non-ephemeral port. (2) The ShuffleHandler service also already supports recovery of previous state after NM restarts.
 
-  * There are two ways to configure auxiliary services, through a manifest file or through the Configuration. If a manifest file is used, auxiliary service configurations are not read from the Configuration. If no manifest file is specified, auxiliary services will be loaded via the prior method of using Configuration properties. One advantage of using the manifest file is that the NMs will detect changes in auxiliary services specified in the manifest file (as determined by the service name and version) and will remove or reload running auxiliary services as needed. To support reloading, AuxiliaryService implementations must perform any cleanup that is needed during the service stop phase for the NM to be able to create a new instance of the auxiliary service.
+  * There are two ways to configure auxiliary services, through a manifest or through the Configuration. Auxiliary services will only be loaded via the prior method of using Configuration properties when an auxiliary services manifest is not enabled. One advantage of using a manifest is that NMs can dynamically reload auxiliary services based on changes to the manifest. To support reloading, AuxiliaryService implementations must perform any cleanup that is needed during the service stop phase for the NM to be able to create a new instance of the auxiliary service.
 
 Auxiliary Service Classpath Isolation
 -------------------------------------
@@ -105,9 +105,11 @@ To launch auxiliary services on a NodeManager, users have to add their jar to No
 
 ### Manifest
 This section describes the auxiliary service manifest for aux-service classpath isolation.
+To use a manifest, the property `yarn.nodemanager.aux-services.manifest.enabled` must be set to true in *yarn-site.xml*.
 
-The manifest file can be set in *yarn-site.xml* under the property `yarn.nodemanager.aux-services.manifest`. The NMs will check this file for new modifications at an interval specified by `yarn.nodemanager.aux-services.manifest.reload-ms` (defaults to 2 minutes; setting interval <= 0 means it will not be reloaded automatically).
-Alternatively, the manifest file may be sent to the NM via REST API by making a PUT call to the endpoint `http://nm-http-address:port/ws/v1/node/auxiliaryservices`.
+To load the manifest file from a filesystem, set the file path in *yarn-site.xml* under the property `yarn.nodemanager.aux-services.manifest`. The NMs will check this file for new modifications at an interval specified by `yarn.nodemanager.aux-services.manifest.reload-ms` (defaults to 0; setting interval <= 0 means it will not be reloaded automatically).
+Alternatively, the manifest file may be sent to an NM via REST API by making a PUT call to the endpoint `http://nm-http-address:port/ws/v1/node/auxiliaryservices`. Note this only updates the manifest on one NM.
+When it reads a new manifest, the NM will add, remove, or reload auxiliary services as needed based on the service names and versions found in the manifest.
 
 An example manifest that configures classpath isolation for a CustomAuxService follows. One or more files may be specified to make up the classpath of a service, with jar or archive formats being supported.
 ```