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// -*- C++ -*-
// $Id$
// ============================================================================
//
// = LIBRARY
// orbsvcs
//
// = FILENAME
// LoadBalancer_i.h
//
// = AUTHOR
// Ossama Othman <ossama@uci.edu>
//
// ============================================================================
#ifndef TAO_LOADBALANCER_I_H
#define TAO_LOADBALANCER_I_H
#include "orbsvcs/LoadBalancingS.h"
#include "ReplicaProxy.h"
#include "DSI_ForwardingProxy.h"
#include "LoadBalancing_Strategy.h"
#include "LoadBalancing_export.h"
# if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
# endif /* ACE_LACKS_PRAGMA_ONCE */
// @@ Ossama: the name of the file and the class are inconsistent.
// @@ Ossama: now is when your idea of keeping the strategy separate
// pays off: we could add strategies to detect misbehaving replicas,
// for example, if they don't send any updates in X seconds then they
// are removed, or maybe we poll them (using _non_existent) before
// removing. I'm sure there are other aspects of the system that
// could be strategized.
class TAO_LoadBalancing_Export TAO_LB_LoadBalancer : public virtual POA_LoadBalancing::LoadBalancer
{
public:
TAO_LB_LoadBalancer (const char *interface_id,
TAO_LB_LoadBalancing_Strategy *strategy,
PortableServer::POA_ptr poa);
// Constructor that initializes this Load Balancer for use with a
// Replica that has the specified interface repository ID.
~TAO_LB_LoadBalancer (void);
// Destructor.
// Local methods
// @@ Ossama: this method is something of my own invention, but i
// think we need to change the interface, to something like:
// load_changed (float old_load, float new_load, proxy)
// that should let us keep the average load (and other similar
// things) pre-computed.
//
void load_changed (TAO_LB_ReplicaProxy *proxy,
CORBA::Environment &ACE_TRY_ENV);
// The load for <proxy> has changed, the LoadBalancer can use this
// opportunity to determine if the load on one of the services is
// too high.
void disconnect (TAO_LB_ReplicaProxy *proxy,
CORBA::Environment &ACE_TRY_ENV)
ACE_THROW_SPEC ((CORBA::SystemException));
// Disconnect proxy from the Load Balancer.
CORBA::Object_ptr replica (CORBA::Environment &ACE_TRY_ENV)
ACE_THROW_SPEC ((CORBA::SystemException));
// Return a reference to the Replica to which client requests should
// be redirected next.
// = See the descriptions in LoadBalancing.idl
virtual LoadBalancing::ReplicaProxy_ptr connect (
LoadBalancing::ReplicaControl_ptr control,
CORBA::Object_ptr replica,
CORBA::Environment &ACE_TRY_ENV)
ACE_THROW_SPEC ((LoadBalancing::ReplicaProxy::NilControl,
LoadBalancing::ReplicaProxy::NilReplica,
CORBA::SystemException));
virtual CORBA::Object_ptr group_identity (CORBA::Environment &ACE_TRY_ENV)
ACE_THROW_SPEC ((CORBA::SystemException));
private:
int init (void);
// Initialize the <redirector_> DSI forwarding proxy.
private:
TAO_LB_DSI_ForwardingProxy redirector_;
// The object that tells the invoking client to forward its requests
// from the LoadBalancer to an actual replica.
TAO_LB_LoadBalancing_Strategy *strategy_;
// The underlying load balancing strategy.
PortableServer::POA_var poa_;
// The POA where the forwarding proxy is activated.
CORBA::Object_var group_identity_;
// The group identity
};
#if defined (__ACE_INLINE__)
#include "LoadBalancer_i.i"
#endif /* __ACE_INLINE__ */
#endif /* TAO_LOADBALANCER_I_H */
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