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Diffstat (limited to 'TAO/examples/Load_Balancing_persistent/Load_Balancer.idl')
| -rw-r--r-- | TAO/examples/Load_Balancing_persistent/Load_Balancer.idl | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/TAO/examples/Load_Balancing_persistent/Load_Balancer.idl b/TAO/examples/Load_Balancing_persistent/Load_Balancer.idl new file mode 100644 index 00000000000..5b7cfa3b61a --- /dev/null +++ b/TAO/examples/Load_Balancing_persistent/Load_Balancer.idl @@ -0,0 +1,172 @@ +// $Id$ + +// ============================================================================ +// +// = FILENAME +// Load_Balancer.idl +// +// = DESCRIPTION +// Interfaces for a simple CORBA Load Balancing service, which can +// be used in conjunction with the Naming Service or alone to +// improve distributed load balancing. See README file for a short +// discussion of other solution approaches for load balancing as +// well as use cases for this approach. +// +// = AUTHOR +// Interfaces in this file came from OrbixNames Load Balancing +// features with modifications by: +// Doug Schmidt (schmidt@cs.wustl.edu) +// Marina Spivak (marina@cs.wustl.edu) +// +// ============================================================================ + +module Load_Balancer +{ + // = TITLE + // Define a module that allows clients to treat a group + // of <Object>s, i.e., an <Object_Group>, as an equivalence class + // to improve distributed load balancing. + // + // = DESCRIPTION + // <Object_Group_Factory> is used to create <Object_Group>s. + // There are two logical types of <Object_Group>s : + // + // 1. Round Robin <Object_Group> -- This <Object_Group> resolves + // requests for arbitrary members in round robin order. + // + // 2. Random <Object_Group> -- This <Object_Group> resolves + // requests for arbitrary members in random order. + // + // Both types of <Object_Group>s have the same interface (i.e., + // <Object_Group>) but different behaviour should be provided + // in interface implementations appropriately. + + // = Module-defined exceptions. + exception no_such_member {}; + exception duplicate_member {}; + exception duplicate_group {}; + exception no_such_group {}; + + // = Module-defined types. + + typedef string Member_ID; + typedef sequence<Member_ID> Member_ID_List; + typedef string Objref; + + struct Member + { + Objref obj; + // IOR of an <Object_Group> member. + + Member_ID id; + // Each member in an <Object_Group> is identified by a unique ID. + }; + + typedef string Group_ID; + typedef sequence<Group_ID> Group_List; + + // = Forward interface decls. + interface Object_Group; + + interface Object_Group_Factory + { + // = TITLE + // A factory that creates different types of + // <Object_Group>s and keeps track of them. + // + // = DESCRIPTION + // Currently, operations for two types of <Object_Group>s are + // defined: random and round robin. + + Object_Group make_round_robin (in Group_ID id) + raises (duplicate_group); + // Creates an <Object_Group> that resolves requests for arbitrary + // members in round robin order. If an <Object_Group>, of any + // type, with Group_ID <id> has already been created by this + // factory, and hasn't been destroyed, a <duplicate_group> + // exception is thrown. + + void unbind_round_robin (in Group_ID id) + raises (no_such_group); + // Unbinds a previous incarnation of the Round Robin if any + + Object_Group make_random (in Group_ID id) + raises (duplicate_group); + // Creates an <Object_Group> that resolves requests for arbitrary + // members in random order. If an <Object_Group>, of any + // type, with Group_ID <id> has already been created by this + // factory, and hasn't been destroyed, a <duplicate_group> + // exception is thrown. + + void unbind_random (in Group_ID id) + raises (no_such_group); + // Unbinds a previous incarnation of the Random groups. + + Object_Group resolve (in Group_ID id) raises (no_such_group); + // Locates and returns an <Object_Group> by its <Group_ID>. If + // no <Object_Group> has <Group_ID> of <id>, throw a + // <no_such_group> exception. + + Group_List round_robin_groups (); + // Lists all the round robin <Object_Group>s which were created + // by this factory, and haven't been destroyed yet, i.e., return + // a sequence of <Group_ID>s of all existing round robin + // <Object_Group>s created by this factory. + + Group_List random_groups (); + // Lists all the random <Object_Group>s which were created + // by this factory, and haven't been destroyed yet, i.e., return + // a sequence of <Group_ID>s of all existing random + // <Object_Group>s created by this factory. + }; + + interface Object_Group + { + // = TITLE + // Holds references for 0 or more objects that form an + // equivalence class, and provides load balancing for those + // objects. + // + // = DESCRIPTION + // Whenever a client needs to find an object of a certain type + // or functionality, it makes a request to the appropriate + // <Object_Group>. The <Object_Group> selects one of its + // members in accordance with the implemented policy (i.e., + // random or round robin), and returnd it to the client, thus + // providing a form of load balancing for its members. + // + readonly attribute string id; + // Each Object Group has its own distinct ID. + + void bind (in Member mem) raises (duplicate_member); + // Adds a new <member> to the <Object_Group>. Note that each + // <Member_ID> in an <Object_Group> must be unique. If the + // group already contains a member with the same <Member_ID>, a + // <duplicate_member> exceptions is thrown. + + void unbind (in Member_ID id) raises (no_such_member); + // Removes a member with the specified <Member_ID> from the + // <Object_Group>. If none of the group's members have a + // Member_ID of <id>, <no_such_member> exception is thrown. + + Objref resolve () raises (no_such_member); + // Returns a member object from this <Object_Group> in accordance with + // load balancing policy it implements, i.e., ``random'' or + // ``round robin.'' If the group contains no members, <no_such_member> + // exception is thrown. + + Objref resolve_with_id (in Member_ID id) raises (no_such_member); + // Returns an object with the specified <Member_ID>. If this + // <Object_Group> contains no members with the specified + // <Member_ID>, <no_such_member> exception is thrown. + + Member_ID_List members (); + // Return a sequence of <Member_ID>s of all of its members. + + void destroy (); + // Cleanup the resources associated with this <Object_Group>. + // Subsequent calls to this <Object_Group> should fail, and its + // <id> should become available. <Object_Group_Factory> + // should no longer list this <Object_Group>. + }; +}; |