YARN-6497. Method length of ResourceManager#serviceInit() is too long (Gergely Novák via jeagles)

(cherry picked from commit cbfed0e82f57e96b8d5309e0613057963840554f)

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

@@ -57,6 +57,7 @@ import org.apache.hadoop.yarn.event.AsyncDispatcher;
 import org.apache.hadoop.yarn.event.Dispatcher;
 import org.apache.hadoop.yarn.event.EventDispatcher;
 import org.apache.hadoop.yarn.event.EventHandler;
+import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.exceptions.YarnRuntimeException;
 import org.apache.hadoop.yarn.server.resourcemanager.ahs.RMApplicationHistoryWriter;
 import org.apache.hadoop.yarn.server.resourcemanager.amlauncher.AMLauncherEventType;
@@ -220,13 +221,7 @@ public class ResourceManager extends CompositeService implements Recoverable {
     rmContext.setConfigurationProvider(configurationProvider);
 
     // load core-site.xml
-    InputStream coreSiteXMLInputStream =
-        this.configurationProvider.getConfigurationInputStream(this.conf,
-            YarnConfiguration.CORE_SITE_CONFIGURATION_FILE);
-    if (coreSiteXMLInputStream != null) {
-      this.conf.addResource(coreSiteXMLInputStream,
-          YarnConfiguration.CORE_SITE_CONFIGURATION_FILE);
-    }
+    loadConfigurationXml(YarnConfiguration.CORE_SITE_CONFIGURATION_FILE);
 
     // Do refreshUserToGroupsMappings with loaded core-site.xml
     Groups.getUserToGroupsMappingServiceWithLoadedConfiguration(this.conf)
@@ -239,13 +234,7 @@ public class ResourceManager extends CompositeService implements Recoverable {
     ProxyUsers.refreshSuperUserGroupsConfiguration(this.conf);
 
     // load yarn-site.xml
-    InputStream yarnSiteXMLInputStream =
-        this.configurationProvider.getConfigurationInputStream(this.conf,
-            YarnConfiguration.YARN_SITE_CONFIGURATION_FILE);
-    if (yarnSiteXMLInputStream != null) {
-      this.conf.addResource(yarnSiteXMLInputStream,
-          YarnConfiguration.YARN_SITE_CONFIGURATION_FILE);
-    }
+    loadConfigurationXml(YarnConfiguration.YARN_SITE_CONFIGURATION_FILE);
 
     validateConfigs(this.conf);
     
@@ -311,6 +300,16 @@ public class ResourceManager extends CompositeService implements Recoverable {
     super.serviceInit(this.conf);
   }
 
+  private void loadConfigurationXml(String configurationFile)
+      throws YarnException, IOException {
+    InputStream configurationInputStream =
+        this.configurationProvider.getConfigurationInputStream(this.conf,
+            configurationFile);
+    if (configurationInputStream != null) {
+      this.conf.addResource(configurationInputStream, configurationFile);
+    }
+  }
+
   protected EmbeddedElector createEmbeddedElector() throws IOException {
     EmbeddedElector elector;
     curatorEnabled =