YARN-9864. Format CS Configuration present in Configuration Store. Contributeed by Prabhu Joseph

(cherry picked from commit 137546a78a45adbfb5ef338c1c2984a97b3cecc2)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/pom.xml

@@ -65,6 +65,16 @@
       <artifactId>mockito-all</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.sun.jersey.jersey-test-framework</groupId>
+      <artifactId>jersey-test-framework-core</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>com.sun.jersey.jersey-test-framework</groupId>
+      <artifactId>jersey-test-framework-grizzly2</artifactId>
+      <scope>test</scope>
+    </dependency>
     <!-- 'mvn dependency:analyze' fails to detect use of this dependency -->
     <dependency>
       <groupId>org.apache.hadoop</groupId>

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/cli/SchedConfCLI.java

@@ -21,6 +21,7 @@ package org.apache.hadoop.yarn.client.cli;
 import com.google.common.annotations.VisibleForTesting;
 import com.sun.jersey.api.client.Client;
 import com.sun.jersey.api.client.ClientResponse;
+import com.sun.jersey.api.client.WebResource;
 import com.sun.jersey.api.client.WebResource.Builder;
 import org.apache.commons.cli.CommandLine;
 import org.apache.commons.cli.GnuParser;
@@ -30,6 +31,7 @@ import org.apache.hadoop.classification.InterfaceAudience.Public;
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.conf.Configured;
+import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.util.Tool;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.webapp.dao.QueueConfigInfo;
@@ -56,6 +58,7 @@ public class SchedConfCLI extends Configured implements Tool {
   private static final String REMOVE_QUEUES_OPTION = "removeQueues";
   private static final String UPDATE_QUEUES_OPTION = "updateQueues";
   private static final String GLOBAL_OPTIONS = "globalUpdates";
+  private static final String FORMAT_CONF = "formatConfig";
   private static final String HELP_CMD = "help";
 
   private static final String CONF_ERR_MSG = "Specify configuration key " +
@@ -83,6 +86,9 @@ public class SchedConfCLI extends Configured implements Tool {
         "Update queue configurations");
     opts.addOption("global", GLOBAL_OPTIONS, true,
         "Update global scheduler configurations");
+    opts.addOption("format", FORMAT_CONF, false,
+        "Format Scheduler Configuration and reload from" +
+        " capacity-scheduler.xml");
     opts.addOption("h", HELP_CMD, false, "Displays help for all commands.");
 
     int exitCode = -1;
@@ -101,6 +107,7 @@ public class SchedConfCLI extends Configured implements Tool {
     }
 
     boolean hasOption = false;
+    boolean format = false;
     SchedConfUpdateInfo updateInfo = new SchedConfUpdateInfo();
     try {
       if (parsedCli.hasOption(ADD_QUEUES_OPTION)) {
@@ -121,6 +128,11 @@ public class SchedConfCLI extends Configured implements Tool {
         hasOption = true;
         globalUpdates(parsedCli.getOptionValue(GLOBAL_OPTIONS), updateInfo);
       }
+      if (parsedCli.hasOption((FORMAT_CONF))) {
+        hasOption = true;
+        format = true;
+      }
+
     } catch (IllegalArgumentException e) {
       System.err.println(e.getMessage());
       return -1;
@@ -133,18 +145,78 @@ public class SchedConfCLI extends Configured implements Tool {
     }
 
     Configuration conf = getConf();
-    return WebAppUtils.execOnActiveRM(conf,
-        this::updateSchedulerConfOnRMNode, updateInfo);
+    if (format) {
+      return WebAppUtils.execOnActiveRM(conf, this::formatSchedulerConf, null);
+    } else {
+      return WebAppUtils.execOnActiveRM(conf,
+          this::updateSchedulerConfOnRMNode, updateInfo);
+    }
+  }
+
+  @VisibleForTesting
+  int formatSchedulerConf(String webAppAddress, WebResource resource)
+      throws Exception {
+    Client webServiceClient = Client.create();
+    ClientResponse response = null;
+    resource = (resource != null) ? resource :
+        webServiceClient.resource(webAppAddress);
+
+    try {
+      Builder builder = null;
+      if (UserGroupInformation.isSecurityEnabled()) {
+        builder = resource
+            .path("ws").path("v1").path("cluster")
+            .path("/scheduler-conf/format")
+            .accept(MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON);
+      } else {
+        builder = resource
+            .path("ws").path("v1").path("cluster")
+            .path("/scheduler-conf/format").queryParam("user.name",
+            UserGroupInformation.getCurrentUser().getShortUserName())
+            .accept(MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON);
+      }
+
+      response = builder.get(ClientResponse.class);
+      if (response != null) {
+        if (response.getStatus() == Status.OK.getStatusCode()) {
+          System.out.println(response.getEntity(String.class));
+          return 0;
+        } else {
+          System.err.println("Failed to format scheduler configuration: " +
+              response.getEntity(String.class));
+        }
+      } else {
+        System.err.println("Failed to format scheduler configuration: " +
+            "null response");
+      }
+      return -1;
+    } finally {
+      if (response != null) {
+        response.close();
+      }
+      webServiceClient.destroy();
+    }
   }
 
-  private int updateSchedulerConfOnRMNode(String webAppAddress,
+  @VisibleForTesting
+  int updateSchedulerConfOnRMNode(String webAppAddress,
       SchedConfUpdateInfo updateInfo) throws Exception {
     Client webServiceClient = Client.create();
     ClientResponse response = null;
+    WebResource resource = webServiceClient.resource(webAppAddress);
+
     try {
-      Builder builder = webServiceClient.resource(webAppAddress)
-          .path("ws").path("v1").path("cluster")
-          .path("scheduler-conf").accept(MediaType.APPLICATION_JSON);
+      Builder builder = null;
+      if (UserGroupInformation.isSecurityEnabled()) {
+        builder = resource.path("ws").path("v1").path("cluster")
+            .path("scheduler-conf").accept(MediaType.APPLICATION_JSON);
+      } else {
+        builder = resource.path("ws").path("v1").path("cluster")
+            .queryParam("user.name",
+            UserGroupInformation.getCurrentUser().getShortUserName())
+            .path("scheduler-conf").accept(MediaType.APPLICATION_JSON);
+      }
+
       builder.entity(YarnWebServiceUtils.toJson(updateInfo,
           SchedConfUpdateInfo.class), MediaType.APPLICATION_JSON);
       response = builder.put(ClientResponse.class);
@@ -253,7 +325,8 @@ public class SchedConfCLI extends Configured implements Tool {
         + "[-remove \"queueRemovePath1;queueRemovePath2\"] "
         + "[-update \"queueUpdatePath1:confKey1=confVal1\"] "
         + "[-global globalConfKey1=globalConfVal1,"
-        + "globalConfKey2=globalConfVal2]\n"
+        + "globalConfKey2=globalConfVal2] "
+        + "[-format]\n"
         + "Example (adding queues): yarn schedulerconf -add "
         + "\"root.a.a1:capacity=100,maximum-capacity=100;root.a.a2:capacity=0,"
         + "maximum-capacity=0\"\n"
@@ -264,6 +337,8 @@ public class SchedConfCLI extends Configured implements Tool {
         + "maximum-capacity=75\"\n"
         + "Example (global scheduler update): yarn schedulerconf "
         + "-global yarn.scheduler.capacity.maximum-applications=10000\n"
+        + "Example (format scheduler configuration): yarn schedulerconf "
+        + "-format\n"
         + "Note: This is an alpha feature, the syntax/options are subject to "
         + "change, please run at your own risk.");
   }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/cli/TestSchedConfCLI.java

@@ -22,12 +22,48 @@ import org.junit.Before;
 import org.junit.Test;
 
 import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
 import java.io.PrintStream;
+import java.security.Principal;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+
+import com.google.inject.Guice;
+import com.google.inject.Singleton;
+import com.google.inject.servlet.ServletModule;
+import com.sun.jersey.guice.spi.container.servlet.GuiceContainer;
+import com.sun.jersey.test.framework.WebAppDescriptor;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.authentication.server.AuthenticationFilter;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
+import org.apache.hadoop.yarn.server.resourcemanager.MockRM;
+import org.apache.hadoop.yarn.server.resourcemanager.ResourceManager;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacitySchedulerConfiguration;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.MutableConfScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.MutableConfigurationProvider;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.JAXBContextResolver;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.RMWebServices;
+import org.apache.hadoop.yarn.webapp.GenericExceptionHandler;
+import org.apache.hadoop.yarn.webapp.GuiceServletConfig;
+import org.apache.hadoop.yarn.webapp.JerseyTestBase;
 import org.apache.hadoop.yarn.webapp.dao.QueueConfigInfo;
 import org.apache.hadoop.yarn.webapp.dao.SchedConfUpdateInfo;
 
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletResponse;
+import javax.servlet.ServletRequest;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletRequestWrapper;
+import javax.servlet.http.HttpServletResponse;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
@@ -35,7 +71,7 @@ import static org.junit.Assert.assertTrue;
 /**
  * Class for testing {@link SchedConfCLI}.
  */
-public class TestSchedConfCLI {
+public class TestSchedConfCLI extends JerseyTestBase {
 
   private ByteArrayOutputStream sysOutStream;
   private PrintStream sysOut;
@@ -45,6 +81,23 @@ public class TestSchedConfCLI {
 
   private SchedConfCLI cli;
 
+  private static MockRM rm;
+  private static String userName;
+  private static CapacitySchedulerConfiguration csConf;
+
+  private static final File CONF_FILE = new File(new File("target",
+      "test-classes"), YarnConfiguration.CS_CONFIGURATION_FILE);
+  private static final File OLD_CONF_FILE = new File(new File("target",
+      "test-classes"), YarnConfiguration.CS_CONFIGURATION_FILE + ".tmp");
+
+  public TestSchedConfCLI() {
+    super(new WebAppDescriptor.Builder(
+        "org.apache.hadoop.yarn.server.resourcemanager.webapp")
+        .contextListenerClass(GuiceServletConfig.class)
+        .filterClass(com.google.inject.servlet.GuiceFilter.class)
+        .contextPath("jersey-guice-filter").servletPath("/").build());
+  }
+
   @Before
   public void setUp() {
     sysOutStream = new ByteArrayOutputStream();
@@ -58,6 +111,138 @@ public class TestSchedConfCLI {
     cli = new SchedConfCLI();
   }
 
+  private static class WebServletModule extends ServletModule {
+    @Override
+    protected void configureServlets() {
+      bind(JAXBContextResolver.class);
+      bind(RMWebServices.class);
+      bind(GenericExceptionHandler.class);
+      Configuration conf = new YarnConfiguration();
+      conf.setClass(YarnConfiguration.RM_SCHEDULER, CapacityScheduler.class,
+          ResourceScheduler.class);
+      conf.set(YarnConfiguration.SCHEDULER_CONFIGURATION_STORE_CLASS,
+          YarnConfiguration.MEMORY_CONFIGURATION_STORE);
+
+      try {
+        userName = UserGroupInformation.getCurrentUser().getShortUserName();
+      } catch (IOException ioe) {
+        throw new RuntimeException("Unable to get current user name "
+            + ioe.getMessage(), ioe);
+      }
+
+      csConf = new CapacitySchedulerConfiguration(new Configuration(false),
+          false);
+      setupQueueConfiguration(csConf);
+
+      try {
+        if (CONF_FILE.exists()) {
+          if (!CONF_FILE.renameTo(OLD_CONF_FILE)) {
+            throw new RuntimeException("Failed to rename conf file");
+          }
+        }
+        FileOutputStream out = new FileOutputStream(CONF_FILE);
+        csConf.writeXml(out);
+        out.close();
+      } catch (IOException e) {
+        throw new RuntimeException("Failed to write XML file", e);
+      }
+
+      rm = new MockRM(conf);
+      bind(ResourceManager.class).toInstance(rm);
+      serve("/*").with(GuiceContainer.class);
+      filter("/*").through(TestRMCustomAuthFilter.class);
+    }
+  }
+
+  /**
+   * Custom filter which sets the Remote User for testing purpose.
+   */
+  @Singleton
+  public static class TestRMCustomAuthFilter extends AuthenticationFilter {
+    @Override
+    public void init(FilterConfig filterConfig) {
+
+    }
+
+    @Override
+    public void doFilter(ServletRequest request, ServletResponse response,
+        FilterChain filterChain) throws IOException, ServletException {
+      HttpServletRequest httpRequest = (HttpServletRequest)request;
+      HttpServletResponse httpResponse = (HttpServletResponse) response;
+      httpRequest = new HttpServletRequestWrapper(httpRequest) {
+        public String getAuthType() {
+          return null;
+        }
+
+        public String getRemoteUser() {
+          return userName;
+        }
+
+        public Principal getUserPrincipal() {
+          return new Principal() {
+            @Override
+            public String getName() {
+              return userName;
+            }
+          };
+        }
+      };
+      doFilter(filterChain, httpRequest, httpResponse);
+    }
+  }
+
+  private static void setupQueueConfiguration(
+      CapacitySchedulerConfiguration config) {
+    config.setQueues(CapacitySchedulerConfiguration.ROOT,
+        new String[]{"testqueue"});
+    String a = CapacitySchedulerConfiguration.ROOT + ".testqueue";
+    config.setCapacity(a, 100f);
+    config.setMaximumCapacity(a, 100f);
+  }
+
+  @Test(timeout = 10000)
+  public void testFormatSchedulerConf() throws Exception {
+    try {
+      super.setUp();
+      GuiceServletConfig.setInjector(
+          Guice.createInjector(new WebServletModule()));
+      ResourceScheduler scheduler = rm.getResourceScheduler();
+      MutableConfigurationProvider provider =
+          ((MutableConfScheduler) scheduler).getMutableConfProvider();
+
+      SchedConfUpdateInfo schedUpdateInfo = new SchedConfUpdateInfo();
+      HashMap<String, String> globalUpdates = new HashMap<>();
+      globalUpdates.put("schedKey1", "schedVal1");
+      schedUpdateInfo.setGlobalParams(globalUpdates);
+
+      provider.logAndApplyMutation(UserGroupInformation.getCurrentUser(),
+          schedUpdateInfo);
+      rm.getRMContext().getRMAdminService().refreshQueues();
+      provider.confirmPendingMutation(true);
+
+      Configuration schedulerConf = provider.getConfiguration();
+      assertEquals("schedVal1", schedulerConf.get("schedKey1"));
+
+      int exitCode = cli.formatSchedulerConf("", resource());
+      assertEquals(0, exitCode);
+
+      schedulerConf = provider.getConfiguration();
+      assertNull(schedulerConf.get("schedKey1"));
+    } finally {
+      if (rm != null) {
+        rm.stop();
+      }
+      CONF_FILE.delete();
+      if (OLD_CONF_FILE.exists()) {
+        if (!OLD_CONF_FILE.renameTo(CONF_FILE)) {
+          throw new RuntimeException("Failed to re-copy old" +
+              " configuration file");
+        }
+      }
+      super.tearDown();
+    }
+  }
+
   @Test(timeout = 10000)
   public void testInvalidConf() throws Exception {
     // conf pair with no key should be invalid

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/MutableConfigurationProvider.java

@@ -65,6 +65,8 @@ public interface MutableConfigurationProvider {
    */
   Configuration getConfiguration();
 
+  void formatConfigurationInStore(Configuration conf) throws Exception;
+
   /**
    * Closes the configuration provider, releasing any required resources.
    * @throws IOException on failure to close

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/FSSchedulerConfigurationStore.java

@@ -156,6 +156,11 @@ public class FSSchedulerConfigurationStore extends YarnConfigurationStore {
         + finalConfigPath);
   }
 
+  @Override
+  public void format() throws Exception {
+    fileSystem.delete(schedulerConfDir, true);
+  }
+
   private Path getFinalConfigPath(Path tempPath) {
     String tempConfigPathStr = tempPath.getName();
     if (!tempConfigPathStr.endsWith(TMP)) {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/InMemoryConfigurationStore.java

@@ -60,6 +60,11 @@ public class InMemoryConfigurationStore extends YarnConfigurationStore {
     pendingMutation = null;
   }
 
+  @Override
+  public void format() {
+    this.schedConf = null;
+  }
+
   @Override
   public synchronized Configuration retrieve() {
     return schedConf;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/LeveldbConfigurationStore.java

@@ -98,6 +98,13 @@ public class LeveldbConfigurationStore extends YarnConfigurationStore {
     }
   }
 
+  @Override
+  public void format() throws Exception {
+    close();
+    FileSystem fs = FileSystem.getLocal(conf);
+    fs.delete(getStorageDir(), true);
+  }
+
   private void initDatabase(Configuration config) throws Exception {
     Path storeRoot = createStorageDir();
     Options options = new Options();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/MutableCSConfigurationProvider.java

@@ -40,6 +40,7 @@ import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
  * CS configuration provider which implements
@@ -58,6 +59,9 @@ public class MutableCSConfigurationProvider implements CSConfigurationProvider,
   private ConfigurationMutationACLPolicy aclMutationPolicy;
   private RMContext rmContext;
 
+  private final ReentrantReadWriteLock formatLock =
+      new ReentrantReadWriteLock();
+
   public MutableCSConfigurationProvider(RMContext rmContext) {
     this.rmContext = rmContext;
   }
@@ -151,17 +155,51 @@ public class MutableCSConfigurationProvider implements CSConfigurationProvider,
     }
   }
 
+  @Override
+  public void formatConfigurationInStore(Configuration config)
+      throws Exception {
+    formatLock.writeLock().lock();
+    try {
+      confStore.format();
+      Configuration initialSchedConf = new Configuration(false);
+      initialSchedConf.addResource(YarnConfiguration.CS_CONFIGURATION_FILE);
+      this.schedConf = new Configuration(false);
+      // We need to explicitly set the key-values in schedConf, otherwise
+      // these configuration keys cannot be deleted when
+      // configuration is reloaded.
+      for (Map.Entry<String, String> kv : initialSchedConf) {
+        schedConf.set(kv.getKey(), kv.getValue());
+      }
+      confStore.initialize(config, schedConf, rmContext);
+      confStore.checkVersion();
+    } catch (Exception e) {
+      throw new IOException(e);
+    } finally {
+      formatLock.writeLock().unlock();
+    }
+  }
+
   @Override
   public void confirmPendingMutation(boolean isValid) throws Exception {
-    confStore.confirmMutation(isValid);
-    if (!isValid) {
-      schedConf = oldConf;
+    formatLock.readLock().lock();
+    try {
+      confStore.confirmMutation(isValid);
+      if (!isValid) {
+        schedConf = oldConf;
+      }
+    } finally {
+      formatLock.readLock().unlock();
     }
   }
 
   @Override
   public void reloadConfigurationFromStore() throws Exception {
-    schedConf = confStore.retrieve();
+    formatLock.readLock().lock();
+    try {
+      schedConf = confStore.retrieve();
+    } finally {
+      formatLock.readLock().unlock();
+    }
   }
 
   private List<String> getSiblingQueues(String queuePath, Configuration conf) {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/YarnConfigurationStore.java

@@ -125,6 +125,13 @@ public abstract class YarnConfigurationStore {
    */
   public abstract Configuration retrieve() throws IOException;
 
+
+  /**
+   * Format the persisted configuration.
+   * @throws IOException on failure to format
+   */
+  public abstract void format() throws Exception;
+
   /**
    * Get a list of confirmed configuration mutations starting from a given id.
    * @param fromId id from which to start getting mutations, inclusive

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/ZKConfigurationStore.java

@@ -132,6 +132,11 @@ public class ZKConfigurationStore extends YarnConfigurationStore {
     return null;
   }
 
+  @Override
+  public void format() throws Exception {
+    zkManager.delete(confStorePath);
+  }
+
   @Override
   public synchronized void storeVersion() throws Exception {
     byte[] data =

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWSConsts.java

@@ -48,6 +48,9 @@ public final class RMWSConsts {
   /** Path for {@code RMWebServices#updateSchedulerConfiguration}. */
   public static final String SCHEDULER_CONF = "/scheduler-conf";
 
+  /** Path for {@code RMWebServices#formatSchedulerConfiguration}. */
+  public static final String FORMAT_SCHEDULER_CONF = "/scheduler-conf/format";
+
   /** Path for {@code RMWebServiceProtocol#dumpSchedulerLogs}. */
   public static final String SCHEDULER_LOGS = "/scheduler/logs";
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java

@@ -2319,6 +2319,37 @@ public class RMWebServices extends WebServices implements RMWebServiceProtocol {
     return rm.getClientRMService().getContainers(request).getContainerList();
   }
 
+  @GET
+  @Path(RMWSConsts.FORMAT_SCHEDULER_CONF)
+  @Produces({ MediaType.APPLICATION_JSON + "; " + JettyUtils.UTF_8,
+       MediaType.APPLICATION_XML + "; " + JettyUtils.UTF_8 })
+  public Response formatSchedulerConfiguration(@Context HttpServletRequest hsr)
+      throws AuthorizationException {
+    // Only admin user allowed to format scheduler conf in configuration store
+    UserGroupInformation callerUGI = getCallerUserGroupInformation(hsr, true);
+    initForWritableEndpoints(callerUGI, true);
+
+    ResourceScheduler scheduler = rm.getResourceScheduler();
+    if (scheduler instanceof MutableConfScheduler
+        && ((MutableConfScheduler) scheduler).isConfigurationMutable()) {
+      try {
+        MutableConfigurationProvider mutableConfigurationProvider =
+            ((MutableConfScheduler) scheduler).getMutableConfProvider();
+        mutableConfigurationProvider.formatConfigurationInStore(conf);
+        return Response.status(Status.OK).entity("Configuration under " +
+            "store successfully formatted.").build();
+      } catch (Exception e) {
+        LOG.error("Exception thrown when formating configuration", e);
+        return Response.status(Status.BAD_REQUEST).entity(e.getMessage())
+            .build();
+      }
+    } else {
+      return Response.status(Status.BAD_REQUEST)
+          .entity("Configuration change only supported by " +
+          "MutableConfScheduler.").build();
+    }
+  }
+
   @PUT
   @Path(RMWSConsts.SCHEDULER_CONF)
   @Produces({ MediaType.APPLICATION_JSON + "; " + JettyUtils.UTF_8,

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/TestFSSchedulerConfigurationStore.java

@@ -36,6 +36,9 @@ import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
+
 
 /**
  * Tests {@link FSSchedulerConfigurationStore}.
@@ -135,6 +138,19 @@ public class TestFSSchedulerConfigurationStore {
     compareConfig(conf, storeConf);
   }
 
+  @Test
+  public void testFormatConfiguration() throws Exception {
+    assertTrue(testSchedulerConfigurationDir.exists());
+    Configuration schedulerConf = new Configuration();
+    schedulerConf.set("a", "a");
+    writeConf(schedulerConf);
+    configurationStore.initialize(conf, conf, null);
+    Configuration storedConfig = configurationStore.retrieve();
+    assertEquals("a", storedConfig.get("a"));
+    configurationStore.format();
+    assertFalse(testSchedulerConfigurationDir.exists());
+  }
+
   @Test
   public void retrieve() throws Exception {
     Configuration schedulerConf = new Configuration();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/TestMutableCSConfigurationProvider.java

@@ -104,6 +104,10 @@ public class TestMutableCSConfigurationProvider {
     confProvider.confirmPendingMutation(false);
     assertNull(confProvider.loadConfiguration(conf).get(
         "yarn.scheduler.capacity.root.a.badKey"));
+
+    confProvider.formatConfigurationInStore(conf);
+    assertNull(confProvider.loadConfiguration(conf)
+        .get("yarn.scheduler.capacity.root.a.goodKey"));
   }
 
   @Test
@@ -137,6 +141,10 @@ public class TestMutableCSConfigurationProvider {
     assertNull(confProvider.loadConfiguration(conf).get(
         "yarn.scheduler.capacity.root.a.badKey"));
 
+    confProvider.formatConfigurationInStore(conf);
+    assertNull(confProvider.loadConfiguration(conf)
+        .get("yarn.scheduler.capacity.root.a.goodKey"));
+
   }
 
   private void writeConf(Configuration conf, String storePath)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/TestZKConfigurationStore.java

@@ -128,6 +128,15 @@ public class TestZKConfigurationStore extends ConfigurationStoreBaseTest {
   }
 
 
+  @Test
+  public void testFormatConfiguration() throws Exception {
+    schedConf.set("key", "val");
+    confStore.initialize(conf, schedConf, rmContext);
+    assertEquals("val", confStore.retrieve().get("key"));
+    confStore.format();
+    assertNull(confStore.retrieve());
+  }
+
   @Test
   public void testPersistUpdatedConfiguration() throws Exception {
     confStore.initialize(conf, schedConf, rmContext);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesConfigurationMutation.java

@@ -189,6 +189,19 @@ public class TestRMWebServicesConfigurationMutation extends JerseyTestBase {
     assertEquals(3, orgConf.getQueues("root").length);
   }
 
+  @Test
+  public void testFormatSchedulerConf() throws Exception {
+    testAddNestedQueue();
+    WebResource r = resource();
+    ClientResponse response = r.path("ws").path("v1").path("cluster")
+        .queryParam("user.name", userName)
+        .path(RMWSConsts.FORMAT_SCHEDULER_CONF)
+        .accept(MediaType.APPLICATION_JSON).get(ClientResponse.class);
+    assertEquals(Status.OK.getStatusCode(), response.getStatus());
+    CapacitySchedulerConfiguration orgConf = getSchedulerConf();
+    assertEquals(3, orgConf.getQueues("root").length);
+  }
+
   @Test
   public void testAddNestedQueue() throws Exception {
     CapacitySchedulerConfiguration orgConf = getSchedulerConf();