Package com.tangosol.net

Interface ServiceLoadBalancer<S extends Service,T extends ServiceLoad>

All Superinterfaces:

Comparator<T>

All Known Subinterfaces:

ProxyServiceLoadBalancer

All Known Implementing Classes:

AbstractServiceLoadBalancer, DefaultProxyServiceLoadBalancer, SimpleServiceLoadBalancer

public interface ServiceLoadBalancer<S extends Service,T extends ServiceLoad>
extends Comparator<T>

A ServiceLoadBalancer is a pluggable strategy for controlling the client load across individual members of a clustered Service.

Since:

Coherence 3.7

Author:

jh 2010.12.07

Method Summary

Modifier and Type	Method	Description
default int	compare(T load1, T load2)	Compare to ServerLoad objects.
List<Member>	getMemberList(Member client)	Called by the Service when a new client connects to obtain an ordered list of Members to which the new client should be redirected.
void	init(S service)	Called by the Service exactly once on this object as part of its initialization.
void	update(Member member, T load)	Update the load balancing strategy in response to a change in a Service utilization.

Methods inherited from interface java.util.Comparator

equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Method Detail

init

void init(S service)

Called by the Service exactly once on this object as part of its initialization.

Parameters:

service - the containing Service

update

void update(Member member,
            T load)

Update the load balancing strategy in response to a change in a Service utilization.

Parameters:

member - the Member for which the utilization changed

load - the updated ServiceLoad; if null, the utilization for the specified Member is unknown (e.g. when the Service on the specified Member leaves the cluster)

getMemberList

List<Member> getMemberList(Member client)

Called by the Service when a new client connects to obtain an ordered list of Members to which the new client should be redirected. If the returned list is null, empty, or contains a single Member that is the "local" Member, the client will remain connected to the calling Service.

Parameters:

client - the Member object that represents the remote client

Returns:

the ordered list of Member objects to which the client should be redirected

compare

default int compare(T load1,
                    T load2)

Compare to ServerLoad objects.

Specified by:

compare in interface Comparator<S extends Service>

Parameters:

load1 - the first ServiceLoad

load2 - the second ServiceLoad

Returns:

a negative integer, zero, or a positive integer indicating if load1 is less then, equal, or greater then load2