ServiceLoadBalancer (Java API Reference for Oracle Coherence)

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 Details
- 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