com.baidu.brpc.client.loadbalance

类 FairStrategy

java.lang.Object

com.baidu.brpc.client.loadbalance.FairStrategy

所有已实现的接口:

LoadBalanceStrategy

public class FairStrategy
extends Object
implements LoadBalanceStrategy

Fair load balance strategy aims to more reasonable distribution of traffic. The principle of traffic distribution is not the same as pv, but the distribution of traffic according to performance, the performance of the machine with multi-point traffic, the poor performance of the machine with less point traffic, the same machine traffic with the same performance, and finally the service performance of all nodes tends to balance, there will be no slow nodes to improve the overall performance of the service.

Algorithm overview: The fair load balancing policy dynamically adjusts the weight of each server and divides it by weight. Rpc client maintains a latency window record rpc time for each server, after processing a traffic, the server updates its own window. If the mean value of the service in the window > the overall mean of the service, reduce its own weight. On the contrary, increase its own weight. When the window is not full, the polling does not adjust the weight.

从以下版本开始:

2018-09-03

作者:

wangjiayin

字段概要

从接口继承的字段 com.baidu.brpc.client.loadbalance.LoadBalanceStrategy

LOAD_BALANCE_FAIR, LOAD_BALANCE_RANDOM, LOAD_BALANCE_ROUND_ROBIN, LOAD_BALANCE_WEIGHT

构造器概要

构造器

构造器和说明
FairStrategy()

方法概要

限定符和类型	方法和说明
protected int	calculateWeight(BrpcChannel group, int timeOut) Calculate the weight of a rpc server
void	destroy()
protected BrpcChannel	fairSelect(com.baidu.brpc.client.loadbalance.FairStrategy.Node root)
protected com.baidu.brpc.client.loadbalance.FairStrategy.Node	generateWeightTreeByLeafNodes(Queue<com.baidu.brpc.client.loadbalance.FairStrategy.Node> leafNodes) generate the tree by leaf nodes the leaf nodes are the real rpc servers the parent nodes used to calculate the sum of it's children's weight
protected long	getRandomLong()
void	init(RpcClient rpcClient)
void	markInvalidInstance(List<BrpcChannel> instances) Since the weight tree will update by a period of time, so if there's any invalid instance, the business should notify the fair strategy.
protected BrpcChannel	randomSelect(List<BrpcChannel> instances)
protected com.baidu.brpc.client.loadbalance.FairStrategy.Node	searchNode(com.baidu.brpc.client.loadbalance.FairStrategy.Node parent, int weight)
BrpcChannel	selectInstance(Request request, List<BrpcChannel> instances, Set<BrpcChannel> selectedInstances) select instance channel from total instances
protected void	updateWeightTree() Update weight of each node of the tree.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

FairStrategy

public FairStrategy()

方法详细资料

init

public void init(RpcClient rpcClient)

指定者:

init 在接口中 LoadBalanceStrategy

selectInstance

public BrpcChannel selectInstance(Request request,
                                  List<BrpcChannel> instances,
                                  Set<BrpcChannel> selectedInstances)

从接口复制的说明: LoadBalanceStrategy

select instance channel from total instances

指定者:

selectInstance 在接口中 LoadBalanceStrategy

参数:

request - request info

instances - total instances, often are all healthy instances

selectedInstances - instances which have been selected.

返回:

the best instance channel

destroy

public void destroy()

指定者:

destroy 在接口中 LoadBalanceStrategy

markInvalidInstance

public void markInvalidInstance(List<BrpcChannel> instances)

Since the weight tree will update by a period of time, so if there's any invalid instance, the business should notify the fair strategy.

randomSelect

protected BrpcChannel randomSelect(List<BrpcChannel> instances)

getRandomLong

protected long getRandomLong()

fairSelect

protected BrpcChannel fairSelect(com.baidu.brpc.client.loadbalance.FairStrategy.Node root)

searchNode

protected com.baidu.brpc.client.loadbalance.FairStrategy.Node searchNode(com.baidu.brpc.client.loadbalance.FairStrategy.Node parent,
                                                                         int weight)

updateWeightTree

protected void updateWeightTree()

Update weight of each node of the tree. By create a new tree and insert into the head of the treeContainer

calculateWeight

protected int calculateWeight(BrpcChannel group,
                              int timeOut)

Calculate the weight of a rpc server

参数:

group - The BrpcChannel instance of a rpc server

timeOut - Read timeout in millis

返回:

Weight num

generateWeightTreeByLeafNodes

protected com.baidu.brpc.client.loadbalance.FairStrategy.Node generateWeightTreeByLeafNodes(Queue<com.baidu.brpc.client.loadbalance.FairStrategy.Node> leafNodes)

generate the tree by leaf nodes the leaf nodes are the real rpc servers the parent nodes used to calculate the sum of it's children's weight

参数:

leafNodes - leaf nodes list

返回:

the root node of the tree