:original_name: mrs_01_0201.html .. _mrs_01_0201: Object Management ================= MRS contains different types of basic objects. :ref:`Table 1 ` describes these objects. .. _mrs_01_0201__table23400575171145: .. table:: **Table 1** MRS basic object overview +------------------+-------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------+ | Object | Description | Example | +==================+===============================================================================+==================================================================================================================+ | Service | Function set that can complete specific business. | KrbServer service and LdapServer service | +------------------+-------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------+ | Service instance | Specific instance of a service, usually called service. | KrbServer service | +------------------+-------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------+ | Service role | Function entity that forms a complete service, usually called role. | KrbServer is composed of the KerberosAdmin role and KerberosServer role. | +------------------+-------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------+ | Role instance | Specific instance of a service role running on a host. | KerberosAdmin that is running on Host2 and KerberosServer that is running on Host3 | +------------------+-------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------+ | Host | An ECS running Linux OS. | Host1 to Host5 | +------------------+-------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------+ | Rack | Physical entity that contains multiple hosts connecting to the same switch. | Rack1 contains Host1 to Host5. | +------------------+-------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------+ | Cluster | Logical entity that consists of multiple hosts and provides various services. | Cluster1 cluster consists of five hosts (Host1 to Host5) and provides services such as KrbServer and LdapServer. | +------------------+-------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------+