标签权重评分Java_权重轮询调度算法 java版本

权重轮询调度算法(Weighted Round-Robin Scheduling)--java版本

由于每台服务器的配置、安装的业务应用等不同，其处理能力会不一样。所以，我们根据服务器的不同处理能力，给每个服务器分配不同的权值，使其能够接受相应权值数的服务请求。

2个java源文件,如下所示：

public interface IProduceStrategy {

public int getPartitionIdForTopic();

}

public class WeightFactorProduceStrategy implements IProduceStrategy {

private int i = -1; //表示上一次选择的服务器

private int cw = 0; //表示当前调度的权值

private int gcd = 0; //当前所有权重的最大公约数 比如 2，4，8 的最大公约数为：2

private int maxWeight;

private List weights = null; //作用计算最大公约数

private PartitionWeightRRParameter weightRRParametersDns[] = null;

/**

* 按照轮询调研权重配置，格式如下:partition1:weight,partition2:weight

* @param partConfig

*/

public WeightFactorProduceStrategy(String partConfig) {

validate(partConfig);

this.initWeigthParam(Tools.parseCsvMap(partConfig));

}

private Pattern pattern = Pattern.compile("([\\d+\\:\\d+],?){1,}");

private void validate(String partConfig) {

if (partConfig.length() <= 0)

throw new InvalidPartitonConfigException("partition config is incorrect :" + partConfig);

else if (partConfig.equals(".") || partConfig.equals(".."))

throw new InvalidPartitonConfigException("partition config is incorrect :" + partConfig);

Matcher matcher = pattern.matcher(partConfig);

if(matcher.find()) {

String rexStr = matcher.group();

if (!rexStr.equals(partConfig))

throw new InvalidPartitonConfigException("partition config is incorrect :" + partConfig);

} else {

throw new InvalidPartitonConfigException("partition config is incorrect :" + partConfig);

}

}

/**

* 格式如下:partition1:weight,partition2:weight

* @param csvMap

*/

private void initWeigthParam(Map csvMap) {

weightRRParametersDns = new PartitionWeightRRParameter[csvMap.size()];

int numPart = 0;

weights = new ArrayList(csvMap.size());

Set> entrySet = csvMap.entrySet();

for(Iterator> its = entrySet.iterator(); its.hasNext(); ) {

Map.Entry entry = its.next();

weights.add(Integer.valueOf(entry.getValue()));

weightRRParametersDns[numPart++] = new PartitionWeightRRParameter(Integer.valueOf(entry.getKey()), Integer.valueOf(entry.getValue()));

}

gcd = getGcdByList(weights);

maxWeight = getMaxWeight();

}

/**

* 计算最大公约数

* @param weight_m 权重数

* @param weight_n 权重数

* @return

*/

private int GCD(int weight_m,int weight_n)

{

int temp;

while(weight_n != 0){

if(weight_m < weight_n){

temp = weight_m;

weight_m = weight_n;

weight_n = temp;

}

temp = weight_m - weight_n;

weight_m = weight_n;

weight_n = temp;

}

return weight_m;

}

/**

*

* @param weights 权重列表

* @param startIndex list索引值,起始位置。

* @param nextGcd 传入最大公约数

* @return

*/

private int getGcdByList(List weights, int startIndex, int nextGcd) {

if ( weights.size() < 2) {

throw new IllegalArgumentException("At least a number of parameters for 2");

}

if (weights.size() == 2 && startIndex == 0) {

return this.GCD(weights.get(startIndex), weights.get(startIndex + 1));

}

if (startIndex + 1 > weights.size() -1 )

return nextGcd;

int curGcd = nextGcd > 0 ? nextGcd : weights.get(startIndex);

int nextIndex = startIndex + 1;

nextGcd = GCD(curGcd, weights.get(startIndex + 1)); //0,1

return getGcdByList(weights, nextIndex, nextGcd);

}

private int getGcdByList(List weights) {

return this.getGcdByList(weights, 0, 0);

}

private int getWeightDns() {

for ( ; ; ) {

i = (i + 1) % weightRRParametersDns.length;

if (i == 0) {

cw = cw - gcd; //表示当前调度的权值

if (cw <= 0) {

cw = maxWeight;

if (cw == 0) {

return 0;

}

}

}

if (weightRRParametersDns[i].getWeight() >= cw ) {

return weightRRParametersDns[i].getPartition();

}

}

}

private int getMaxWeight() {

int max = 0;

for (int i = 0; i< weightRRParametersDns.length;i++) {

if (weightRRParametersDns[i].getWeight() >= max) {

max = weightRRParametersDns[i].getWeight();

}

}

return max;

}

public int getPartitionIdForTopic() {

return this.getWeightDns();

}

/**

* 分区权重参数类

*/

static class PartitionWeightRRParameter {

private int partition;

private int weight;

public PartitionWeightRRParameter(int partition, int weight) {

this.partition = partition;

this.weight = weight;

}

public int getPartition() {

return partition;

}

public int getWeight() {

return weight;

}

}

}

单元测试类：

public class WeightFactorProduceStrategyTest {

@Test

public void testGetPartitionIdForTopic() throws Exception {

IProduceStrategy weightFcProStrategy = new WeightFactorProduceStrategy("0:5,1:15,2:20");

for (int i = 0; i < 40; i++) {

// weightFcProStrategy.getPartitionIdForTopic();

System.out.println(weightFcProStrategy.getPartitionIdForTopic());

}

}

}

测试结果如下:2

2

1

2

1

2

1

0

2

2

1

2

1

2

1

0

2

2

1

2

1

2

1

0

2

2

1

2

1

2

1

0

2

2

1

2

1

2

1

0