protected void processConfigurationChanges(String dataDirectory,
                                             Map<String, Map<String, String>> kerberosConfigurations,
                                             Map<String, Set<String>> propertiesToBeRemoved,
                                             KerberosDescriptor kerberosDescriptor,
                                             UpdateConfigurationPolicy updateConfigurationPolicy)
      throws AmbariException {
    actionLog.writeStdOut("Determining configuration changes");

    // If there are configurations to set, create a (temporary) data file to store the configuration
    // updates and fill it will the relevant configurations.
    if (!kerberosConfigurations.isEmpty()) {
      if (dataDirectory == null) {
        String message = "The data directory has not been set.  Generated data can not be stored.";
        LOG.error(message);
        throw new AmbariException(message);
      }

      // Determine what the relevant Kerberos identity-related properties are...
      Map<String, Set<String>> kerberosIdentityProperties = getIdentityProperties(kerberosDescriptor, null);

      // Determine what the existing properties are...
      Map<String, Map<String, String>> existingProperties = configHelper.getEffectiveConfigProperties(getClusterName(), null);

      File configFile = new File(dataDirectory, KerberosConfigDataFileWriter.DATA_FILE_NAME);
      KerberosConfigDataFileWriter kerberosConfDataFileWriter = null;

      actionLog.writeStdOut(String.format("Writing configuration changes metadata file to %s", configFile.getAbsolutePath()));
      try {
        kerberosConfDataFileWriter = kerberosConfigDataFileWriterFactory.createKerberosConfigDataFileWriter(configFile);
        // add properties to be set
        for (Map.Entry<String, Map<String, String>> entry : kerberosConfigurations.entrySet()) {
          String type = entry.getKey();
          Map<String, String> properties = entry.getValue();

          if (properties != null) {
            for (Map.Entry<String, String> configTypeEntry : properties.entrySet()) {

              // Determine if this configuration should be written or not...
              String propertyName = configTypeEntry.getKey();
              if (includeConfiguration(type, propertyName, updateConfigurationPolicy, existingProperties, kerberosIdentityProperties)) {
                kerberosConfDataFileWriter.addRecord(type,
                    propertyName,
                    configTypeEntry.getValue(),
                    KerberosConfigDataFileWriter.OPERATION_TYPE_SET);
              }
            }
          }
        }
        // add properties to be removed
        if (propertiesToBeRemoved != null) {
          for (Map.Entry<String, Set<String>> entry : propertiesToBeRemoved.entrySet()) {
            String type = entry.getKey();
            Set<String> properties = entry.getValue();

            if (properties != null) {
              for (String property : properties) {
                kerberosConfDataFileWriter.addRecord(type,
                    property,
                    "",
                    KerberosConfigDataFileWriter.OPERATION_TYPE_REMOVE);
              }
            }
          }
        }
      } catch (IOException e) {
        String message = String.format("Failed to write kerberos configurations file - %s", configFile.getAbsolutePath());
        LOG.error(message, e);
        actionLog.writeStdOut(message);
        actionLog.writeStdErr(message + "\n" + e.getLocalizedMessage());
        throw new AmbariException(message, e);
      } finally {
        if (kerberosConfDataFileWriter != null) {
          try {
            kerberosConfDataFileWriter.close();
          } catch (IOException e) {
            String message = "Failed to close the kerberos configurations file writer";
            LOG.warn(message, e);
            actionLog.writeStdOut(message);
            actionLog.writeStdErr(message + "\n" + e.getLocalizedMessage());
          }
        }
      }
    }
  }
Processes configuration changes to determine if any work needs to be done.
<p/>
If work is to be done, a data file containing the details is created so it they changes may be
processed in the appropriate stage.

@param dataDirectory             the directory in which to write the configuration changes data file
@param kerberosConfigurations    the Kerberos-specific configuration map
@param propertiesToBeRemoved     a map of properties to be removed from the current configuration,
                                 grouped by configuration type.
@param kerberosDescriptor        the Kerberos descriptor
@param updateConfigurationPolicy the policy used to determine which configurations to update
@throws AmbariException
ambari-server/src/main/java/org/apache/ambari/server/serveraction/kerberos/AbstractPrepareKerberosServerAction.java