YARN-6372. Add default value for NM disk validator (Contributed by Yufei Gu via Daniel Templeton)

(cherry picked from commit e486569197e10bf48731d9e7ef5c031987c26acc)

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

@@ -32,6 +32,7 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.ha.ActiveStandbyElector;
 import org.apache.hadoop.http.HttpConfig;
 import org.apache.hadoop.net.NetUtils;
+import org.apache.hadoop.util.BasicDiskValidator;
 import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.yarn.api.ApplicationConstants;
 
@@ -918,7 +919,7 @@ public class YarnConfiguration extends Configuration {
 
   /** Disk Validator. */
   public static final String DISK_VALIDATOR = NM_PREFIX + "disk-validator";
-  public static final String DEFAULT_DISK_VALIDATOR = "basic";
+  public static final String DEFAULT_DISK_VALIDATOR = BasicDiskValidator.NAME;
 
   /**
    * Maximum size of contain's diagnostics to keep for relaunching container

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

@@ -181,7 +181,8 @@ public class DirectoryCollection {
     conf = new YarnConfiguration();
     try {
       diskValidator = DiskValidatorFactory.getInstance(
-          conf.get(YarnConfiguration.DISK_VALIDATOR));
+          conf.get(YarnConfiguration.DISK_VALIDATOR,
+              YarnConfiguration.DEFAULT_DISK_VALIDATOR));
       LOG.info("Disk Validator: " + YarnConfiguration.DISK_VALIDATOR +
           " is loaded.");
     } catch (Exception e) {

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

@@ -127,7 +127,8 @@ public class ContainerLocalizer {
     this.recordFactory = recordFactory;
     this.conf = new YarnConfiguration();
     this.diskValidator = DiskValidatorFactory.getInstance(
-        conf.get(YarnConfiguration.DISK_VALIDATOR));
+        conf.get(YarnConfiguration.DISK_VALIDATOR,
+            YarnConfiguration.DEFAULT_DISK_VALIDATOR));
     LOG.info("Disk Validator: " + YarnConfiguration.DISK_VALIDATOR +
         " is loaded.");
     this.appCacheDirContextName = String.format(APPCACHE_CTXT_FMT, appId);

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

@@ -261,7 +261,8 @@ public class ResourceLocalizationService extends CompositeService
     }
 
     diskValidator = DiskValidatorFactory.getInstance(
-        conf.get(YarnConfiguration.DISK_VALIDATOR));
+        conf.get(YarnConfiguration.DISK_VALIDATOR,
+            YarnConfiguration.DEFAULT_DISK_VALIDATOR));
     LOG.info("Disk Validator: " + YarnConfiguration.DISK_VALIDATOR +
         " is loaded.");
     cacheTargetSize =