| | |
| | | |
| | | /** |
| | | * 分组下机器地址相同,不同JOB均匀散列在不同机器上,保证分组下机器分配JOB平均;且每个JOB固定调度其中一台机器; |
| | | * a、virtual node:解决不均衡问题 |
| | | * b、hash method replace hashCode:String的hashCode可能重复,需要进一步扩大hashCode的取值范围 |
| | | * a、virtual node:解决不均衡问题 |
| | | * b、hash method replace hashCode:String的hashCode可能重复,需要进一步扩大hashCode的取值范围 |
| | | * Created by xuxueli on 17/3/10. |
| | | */ |
| | | public class ExecutorRouteConsistentHash extends ExecutorRouter { |
| | |
| | | |
| | | /** |
| | | * get hash code on 2^32 ring (md5散列的方式计算hash值) |
| | | * |
| | | * @param key |
| | | * @return |
| | | */ |
| | |
| | | |
| | | // hash code, Truncate to 32-bits |
| | | long hashCode = ((long) (digest[3] & 0xFF) << 24) |
| | | | ((long) (digest[2] & 0xFF) << 16) |
| | | | ((long) (digest[1] & 0xFF) << 8) |
| | | | (digest[0] & 0xFF); |
| | | | ((long) (digest[2] & 0xFF) << 16) |
| | | | ((long) (digest[1] & 0xFF) << 8) |
| | | | (digest[0] & 0xFF); |
| | | |
| | | long truncateHashCode = hashCode & 0xffffffffL; |
| | | return truncateHashCode; |
| | |
| | | // ------A1------A2-------A3------ |
| | | // -----------J1------------------ |
| | | TreeMap<Long, String> addressRing = new TreeMap<Long, String>(); |
| | | for (String address: addressList) { |
| | | for (String address : addressList) { |
| | | for (int i = 0; i < VIRTUAL_NODE_NUM; i++) { |
| | | long addressHash = hash("SHARD-" + address + "-NODE-" + i); |
| | | addressRing.put(addressHash, address); |