YARN-8204. Added a flag to disable YARN service upgrade.

            Contributed by Chandni Singh

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/main/java/org/apache/hadoop/yarn/service/client/ServiceClient.java

@@ -74,6 +74,7 @@ import org.apache.hadoop.yarn.service.containerlaunch.ClasspathConstructor;
 import org.apache.hadoop.yarn.service.containerlaunch.JavaCommandLineBuilder;
 import org.apache.hadoop.yarn.service.exceptions.BadClusterStateException;
 import org.apache.hadoop.yarn.service.exceptions.BadConfigException;
+import org.apache.hadoop.yarn.service.exceptions.ErrorStrings;
 import org.apache.hadoop.yarn.service.exceptions.SliderException;
 import org.apache.hadoop.yarn.service.provider.AbstractClientProvider;
 import org.apache.hadoop.yarn.service.provider.ProviderUtils;
@@ -224,6 +225,12 @@ public class ServiceClient extends AppAdminClient implements SliderExitCodes,
 
   public int initiateUpgrade(Service service) throws YarnException,
       IOException {
+    boolean upgradeEnabled = getConfig().getBoolean(
+        YARN_SERVICE_UPGRADE_ENABLED,
+        YARN_SERVICE_UPGRADE_ENABLED_DEFAULT);
+    if (!upgradeEnabled) {
+      throw new YarnException(ErrorStrings.SERVICE_UPGRADE_DISABLED);
+    }
     Service persistedService =
         ServiceApiUtil.loadService(fs, service.getName());
     if (!StringUtils.isEmpty(persistedService.getId())) {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/main/java/org/apache/hadoop/yarn/service/conf/YarnServiceConf.java

@@ -127,6 +127,13 @@ public class YarnServiceConf {
   public static final String YARN_SERVICE_CONTAINER_HEALTH_THRESHOLD_PREFIX =
       YARN_SERVICE_PREFIX + "container-health-threshold.";
 
+  /**
+   * Upgrade feature enabled for services.
+   */
+  public static final String YARN_SERVICE_UPGRADE_ENABLED =
+      "yarn.service.upgrade.enabled";
+  public static final boolean YARN_SERVICE_UPGRADE_ENABLED_DEFAULT = false;
+
   /**
    * The container health threshold percent when explicitly set for a specific
    * component or globally for all components, will schedule a health check

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/main/java/org/apache/hadoop/yarn/service/exceptions/ErrorStrings.java

@@ -39,4 +39,6 @@ public interface ErrorStrings {
     "Too many arguments";
   String ERROR_DUPLICATE_ENTRY = "Duplicate entry for ";
 
+  String SERVICE_UPGRADE_DISABLED = "Service upgrade is disabled.";
+
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/test/java/org/apache/hadoop/yarn/service/TestYarnNativeServices.java

@@ -375,6 +375,7 @@ public class TestYarnNativeServices extends ServiceTestUtils {
   @Test(timeout = 200000)
   public void testUpgrade() throws Exception {
     setupInternal(NUM_NMS);
+    getConf().setBoolean(YARN_SERVICE_UPGRADE_ENABLED, true);
     ServiceClient client = createClient(getConf());
 
     Service service = createExampleApplication();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/test/java/org/apache/hadoop/yarn/service/client/TestServiceClient.java

@@ -39,6 +39,8 @@ import org.apache.hadoop.yarn.service.api.records.Component;
 import org.apache.hadoop.yarn.service.api.records.Container;
 import org.apache.hadoop.yarn.service.api.records.Service;
 import org.apache.hadoop.yarn.service.api.records.ServiceState;
+import org.apache.hadoop.yarn.service.conf.YarnServiceConf;
+import org.apache.hadoop.yarn.service.exceptions.ErrorStrings;
 import org.apache.hadoop.yarn.service.utils.ServiceApiUtil;
 import org.junit.Assert;
 import org.junit.Rule;
@@ -66,10 +68,27 @@ public class TestServiceClient {
   public ServiceTestUtils.ServiceFSWatcher rule =
       new ServiceTestUtils.ServiceFSWatcher();
 
+  @Test
+  public void testUpgradeDisabledByDefault() throws Exception {
+    Service service = createService();
+    ServiceClient client = MockServiceClient.create(rule, service, false);
+
+    //upgrade the service
+    service.setVersion("v2");
+    try {
+      client.initiateUpgrade(service);
+    } catch (YarnException ex) {
+      Assert.assertEquals(ErrorStrings.SERVICE_UPGRADE_DISABLED,
+          ex.getMessage());
+      return;
+    }
+    Assert.fail();
+  }
+
   @Test
   public void testActionServiceUpgrade() throws Exception {
     Service service = createService();
-    ServiceClient client = MockServiceClient.create(rule, service);
+    ServiceClient client = MockServiceClient.create(rule, service, true);
 
     //upgrade the service
     service.setVersion("v2");
@@ -85,7 +104,7 @@ public class TestServiceClient {
   @Test
   public void testActionCompInstanceUpgrade() throws Exception {
     Service service = createService();
-    MockServiceClient client = MockServiceClient.create(rule, service);
+    MockServiceClient client = MockServiceClient.create(rule, service, true);
 
     //upgrade the service
     service.setVersion("v2");
@@ -127,7 +146,7 @@ public class TestServiceClient {
     }
 
     static MockServiceClient create(ServiceTestUtils.ServiceFSWatcher rule,
-        Service service)
+        Service service, boolean enableUpgrade)
         throws IOException, YarnException {
       MockServiceClient client = new MockServiceClient();
 
@@ -163,7 +182,8 @@ public class TestServiceClient {
       client.setFileSystem(rule.getFs());
       client.setYarnClient(yarnClient);
       client.service = service;
-
+      rule.getConf().setBoolean(YarnServiceConf.YARN_SERVICE_UPGRADE_ENABLED,
+          enableUpgrade);
       client.init(rule.getConf());
       client.start();
       client.actionCreate(service);