public String getHostName() {
    return hostEntity != null ? hostEntity.getHostName() : null;
  }
Service mappings must be fetched {@link FetchType#EAGER} since they are
required when processing {@link KerberosKeytabPrincipalEntity} instances
and turning them into {@link ResolvedKerberosPrincipal}.
ambari-server/src/main/java/org/apache/ambari/server/orm/entities/KerberosKeytabPrincipalEntity.java