架构师训练营 1 期 - 第五周作业 (vaik)

import java.util.*;
//基于虚拟节点的一致性哈希算法public class DistributedConsistentHashingByVirtualNode {    //缓存服务器虚拟节点映射列表    private SortedMap<Integer,String> virtualCacheServerKeyList =new TreeMap<>();
    //每台缓存服务器映射的虚拟节点数量，默认200    private int cacheServerMappingNumber = 200;
    //构建类时提供可设置每台缓存服务器映射的虚拟节点数量    public DistributedConsistentHashingByVirtualNode(int cacheServerMappingNumber) {        this.cacheServerMappingNumber = cacheServerMappingNumber;    }
    //添加缓存服务器    public void AddCacheServer(String serverIp){        for(int i=0;i<cacheServerMappingNumber;i++){            String nodeKey = i*10000+"_"+serverIp+"_"+i*10000;            int hashCode = nodeKey.hashCode();            virtualCacheServerKeyList.put(hashCode,serverIp);        }    }
    //删除缓存服务器    public void RemoveCacheServer(String serverIp){        for(int i=0;i<cacheServerMappingNumber;i++){            String nodeKey = i*10000+"_"+serverIp+"_"+i*10000;            int hashCode = nodeKey.hashCode();            virtualCacheServerKeyList.remove(hashCode);        }    }
    //根据缓存Key查找缓存所在的缓存服务器IP    public String getCacheServerIpByKey(String key){        int hashCode = key.hashCode();        String ip = "";        Iterator<Map.Entry<Integer,String>> entries = virtualCacheServerKeyList.entrySet().iterator();        while(entries.hasNext()){            Map.Entry<Integer, String> entry = entries.next();            int virtualCacheServerKey = entry.getKey();            ip = entry.getValue();            //判断顺时针与hashCode最接近的缓存服务器节点            if(hashCode<=virtualCacheServerKey){                break;            }        }        return ip;    }
    //打印虚拟结点分布情况    public void printAllVirtualCacheServerKey(){        Iterator<Map.Entry<Integer,String>> entries = virtualCacheServerKeyList.entrySet().iterator();        while(entries.hasNext()){            Map.Entry<Integer, String> entry = entries.next();            int virtualCacheServerKey = entry.getKey();            String ip = entry.getValue();            System.out.println("virtualCacheServerKey:"+virtualCacheServerKey+" ip:"+ip);        }    }}

import java.util.HashMap;import java.util.Random;
public class TestDistributedConsistentHashingByVirtualNode {    public static void main(String[] args){        DistributedConsistentHashingByVirtualNode nodeServer = new DistributedConsistentHashingByVirtualNode(100);
        String nodeServerIp1 = "192.168.1.1";        String nodeServerIp2 = "192.168.1.2";        String nodeServerIp3 = "192.168.1.3";        String nodeServerIp4 = "192.168.1.4";        String nodeServerIp5 = "192.168.1.5";        String nodeServerIp6 = "192.168.1.6";        String nodeServerIp7 = "192.168.1.7";        String nodeServerIp8 = "192.168.1.8";        String nodeServerIp9 = "192.168.1.9";        String nodeServerIp10 = "192.168.1.10";
        nodeServer.AddCacheServer(nodeServerIp1);        nodeServer.AddCacheServer(nodeServerIp2);        nodeServer.AddCacheServer(nodeServerIp3);        nodeServer.AddCacheServer(nodeServerIp4);        nodeServer.AddCacheServer(nodeServerIp5);        nodeServer.AddCacheServer(nodeServerIp6);        nodeServer.AddCacheServer(nodeServerIp7);        nodeServer.AddCacheServer(nodeServerIp8);        nodeServer.AddCacheServer(nodeServerIp9);        nodeServer.AddCacheServer(nodeServerIp10);
        //nodeServer.printAllVirtualCacheServerKey();        HashMap<String,Integer> result = new HashMap<>();
        //测试100万随机Key(3到100位长度的Key）在 10个服务器上的分布比例        for (int i=0 ; i<1000000; i++){            Random random=new Random();            int number=random.nextInt(98)+3;            String key = getRandomString(number);            String nodeServerIp = nodeServer.getCacheServerIpByKey(key);            if(result.containsKey(nodeServerIp)){                result.put(nodeServerIp,result.get(nodeServerIp)+1);            }else{                result.put(nodeServerIp,1);            }        }
        for (String key: result.keySet()) {            int num = result.get(key);            double rate = (double) num/1000000;            String rateStr = String.format("%.4f",rate*100);            System.out.println("ServerIP:"+key+" Key数量："+num + " 占比："+rateStr+"% ");        }    }
    //取固定位数的随机字符串    public static String getRandomString(int length){        String str="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";        Random random=new Random();        StringBuffer sb=new StringBuffer();        for(int i=0;i<length;i++){            int number=random.nextInt(62);            sb.append(str.charAt(number));        }        return sb.toString();    }}