AMBARI-6500. Upgrade creates new configs version even if there is nothing to update (aonishuk)

ambari-server/src/main/java/org/apache/ambari/server/upgrade/AbstractUpgradeCatalog.java

@@ -17,6 +17,7 @@
  */
 package org.apache.ambari.server.upgrade;
 
+import com.google.common.collect.Maps;
 import com.google.inject.Inject;
 import com.google.inject.Injector;
 import com.google.inject.Provider;
@@ -202,30 +203,36 @@ public abstract class AbstractUpgradeCatalog implements UpgradeCatalog {
           Map<String, Config> all = cluster.getConfigsByType(configType);
           if (all == null || !all.containsKey(newTag) || properties.size() > 0) {
 
+            Map<String, String> oldConfigProperties = oldConfig.getProperties();
+
             Map<String, String> mergedProperties =
-              mergeProperties(oldConfig.getProperties(), properties, updateIfExists);
-
-            LOG.info("Applying configuration with tag '%s' to " +
-              "cluster '%s'", newTag, cluster.getClusterName());
-
-            ConfigurationRequest cr = new ConfigurationRequest();
-            cr.setClusterName(cluster.getClusterName());
-            cr.setVersionTag(newTag);
-            cr.setType(configType);
-            cr.setProperties(mergedProperties);
-            controller.createConfiguration(cr);
-
-            Config baseConfig = cluster.getConfig(cr.getType(), cr.getVersionTag());
-            if (baseConfig != null) {
-              String authName = "ambari-upgrade";
-
-              if (cluster.addDesiredConfig(authName, baseConfig)) {
-                LOG.info("cluster '" + cluster.getClusterName() + "' "
-                  + "changed by: '" + authName + "'; "
-                  + "type='" + baseConfig.getType() + "' "
-                  + "tag='" + baseConfig.getVersionTag() + "'"
-                  + " from='"+ oldConfig.getVersionTag() + "'");
+              mergeProperties(oldConfigProperties, properties, updateIfExists);
+
+            if (!Maps.difference(oldConfigProperties, mergedProperties).areEqual()) {
+              LOG.info("Applying configuration with tag '%s' to " +
+                "cluster '%s'", newTag, cluster.getClusterName());
+
+              ConfigurationRequest cr = new ConfigurationRequest();
+              cr.setClusterName(cluster.getClusterName());
+              cr.setVersionTag(newTag);
+              cr.setType(configType);
+              cr.setProperties(mergedProperties);
+              controller.createConfiguration(cr);
+
+              Config baseConfig = cluster.getConfig(cr.getType(), cr.getVersionTag());
+              if (baseConfig != null) {
+                String authName = "ambari-upgrade";
+
+                if (cluster.addDesiredConfig(authName, baseConfig)) {
+                  LOG.info("cluster '" + cluster.getClusterName() + "' "
+                    + "changed by: '" + authName + "'; "
+                    + "type='" + baseConfig.getType() + "' "
+                    + "tag='" + baseConfig.getVersionTag() + "'"
+                    + " from='" + oldConfig.getVersionTag() + "'");
+                }
               }
+            } else {
+              LOG.info("No changes detected to config " + configType + ". Skipping configuration properties update");
             }
           }
         }

ambari-server/src/test/java/org/apache/ambari/server/upgrade/UpgradeCatalogTest.java

@@ -182,7 +182,7 @@ public class UpgradeCatalogTest {
       Collections.singletonMap("x", "y"), false);
     config = cluster.getDesiredConfigByType("global");
     Assert.assertNotNull(config);
-    Assert.assertNotSame(version, config.getVersionTag());
+    Assert.assertSame(version, config.getVersionTag());
     Assert.assertTrue(config.getProperties().containsKey("x"));
     Assert.assertEquals("z", config.getProperties().get("x"));
   }