提交 c55b3c0f 编写于 作者: zlt2000's avatar zlt2000

增加分布式id生成器

上级 d5de392d
......@@ -31,7 +31,7 @@
## 2. 项目总体架构图
![](https://gitee.com/zlt2000/images/raw/master/spring cloud 微服务架构图.jpg)
![](https://gitee.com/zlt2000/images/raw/master/springcloud微服务架构图.jpg)
 
......@@ -54,12 +54,12 @@
* 分布式锁
* 分布式任务调度器
* 支持CI/CD持续集成(包括前端和后端)
* 分布式高性能Id生成器
* **系统监控功能**
* 服务调用链监控
* 应用拓扑图
* 慢服务检测
* 服务Metric监控
* 应用监控(应用健康、JVM、内存、线程)
* 错误日志查询
* 慢查询SQL监控
......
package com.central.common.utils;
/**
* 高效分布式ID生成算法(sequence),基于Snowflake算法优化实现64位自增ID算法。
* 其中解决时间回拨问题的优化方案如下:
* 1. 如果发现当前时间少于上次生成id的时间(时间回拨),着计算回拨的时间差
* 2. 如果时间差(offset)小于等于5ms,着等待 offset * 2 的时间再生成
* 3. 如果offset大于5,则直接抛出异常
*
* @author zlt
* @date 2019/3/5
*/
public class IdGenerator {
private static Sequence WORKER = new Sequence();
public static long getId() {
return WORKER.nextId();
}
public static String getIdStr() {
return String.valueOf(WORKER.nextId());
}
}
package com.central.common.utils;
import cn.hutool.core.date.SystemClock;
import cn.hutool.core.lang.Assert;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.core.toolkit.StringPool;
import lombok.extern.slf4j.Slf4j;
import java.lang.management.ManagementFactory;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.util.concurrent.ThreadLocalRandom;
/**
* 分布式高效有序ID生成器
* 优化开源项目:http://git.oschina.net/yu120/sequence
*
* Twitter_Snowflake<br>
* SnowFlake的结构如下(每部分用-分开):<br>
* 0 - 0000000000 0000000000 0000000000 0000000000 0 - 00000 - 00000 -
* 000000000000 <br>
* 1位标识,由于long基本类型在Java中是带符号的,最高位是符号位,正数是0,负数是1,所以id一般是正数,最高位是0<br>
* 41位时间截(毫秒级),注意,41位时间截不是存储当前时间的时间截,而是存储时间截的差值(当前时间截 - 开始时间截)
* 得到的值),这里的的开始时间截,一般是我们的id生成器开始使用的时间,由我们程序来指定的(如下下面程序IdWorker类的startTime属性)。41位的时间截,可以使用69年,年T
* = (1L << 41) / (1000L * 60 * 60 * 24 * 365) = 69<br>
* 10位的数据机器位,可以部署在1024个节点,包括5位datacenterId和5位workerId<br>
* 12位序列,毫秒内的计数,12位的计数顺序号支持每个节点每毫秒(同一机器,同一时间截)产生4096个ID序号<br>
* 加起来刚好64位,为一个Long型。<br>
* SnowFlake的优点是,整体上按照时间自增排序,并且整个分布式系统内不会产生ID碰撞(由数据中心ID和机器ID作区分),并且效率较高,经测试,SnowFlake每秒能够产生26万ID左右。
*
* @author zlt
* @date 2019/3/5
*/
@Slf4j
public class Sequence {
/**
* 时间起始标记点,作为基准,一般取系统的最近时间(一旦确定不能变动)
*/
private final long twepoch = 1288834974657L;
/**
* 机器标识位数
*/
private final long workerIdBits = 5L;
private final long datacenterIdBits = 5L;
private final long maxWorkerId = -1L ^ (-1L << workerIdBits);
private final long maxDatacenterId = -1L ^ (-1L << datacenterIdBits);
/**
* 毫秒内自增位
*/
private final long sequenceBits = 12L;
private final long workerIdShift = sequenceBits;
private final long datacenterIdShift = sequenceBits + workerIdBits;
/**
* 时间戳左移动位
*/
private final long timestampLeftShift = sequenceBits + workerIdBits + datacenterIdBits;
private final long sequenceMask = -1L ^ (-1L << sequenceBits);
private final long workerId;
/**
* 数据标识 ID 部分
*/
private final long datacenterId;
/**
* 并发控制
*/
private long sequence = 0L;
/**
* 上次生产 ID 时间戳
*/
private long lastTimestamp = -1L;
/**
* 时间回拨最长时间(ms),超过这个时间就抛出异常
*/
private long timestampOffset = 5L;
public Sequence() {
this.datacenterId = getDatacenterId(maxDatacenterId);
this.workerId = getMaxWorkerId(datacenterId, maxWorkerId);
}
/**
* <p>
* 有参构造器
* </p>
*
* @param workerId 工作机器 ID
* @param datacenterId 序列号
*/
public Sequence(long workerId, long datacenterId) {
Assert.isFalse(workerId > maxWorkerId || workerId < 0,
String.format("worker Id can't be greater than %d or less than 0", maxWorkerId));
Assert.isFalse(datacenterId > maxDatacenterId || datacenterId < 0,
String.format("datacenter Id can't be greater than %d or less than 0", maxDatacenterId));
this.workerId = workerId;
this.datacenterId = datacenterId;
}
/**
* <p>
* 获取 maxWorkerId
* </p>
*/
protected static long getMaxWorkerId(long datacenterId, long maxWorkerId) {
StringBuilder mpid = new StringBuilder();
mpid.append(datacenterId);
String name = ManagementFactory.getRuntimeMXBean().getName();
if (StrUtil.isNotEmpty(name)) {
/*
* GET jvmPid
*/
mpid.append(name.split(StringPool.AT)[0]);
}
/*
* MAC + PID 的 hashcode 获取16个低位
*/
return (mpid.toString().hashCode() & 0xffff) % (maxWorkerId + 1);
}
/**
* <p>
* 数据标识id部分
* </p>
*/
protected static long getDatacenterId(long maxDatacenterId) {
long id = 0L;
try {
InetAddress ip = InetAddress.getLocalHost();
NetworkInterface network = NetworkInterface.getByInetAddress(ip);
if (network == null) {
id = 1L;
} else {
byte[] mac = network.getHardwareAddress();
if (null != mac) {
id = ((0x000000FF & (long) mac[mac.length - 1]) | (0x0000FF00 & (((long) mac[mac.length - 2]) << 8))) >> 6;
id = id % (maxDatacenterId + 1);
}
}
} catch (Exception e) {
log.warn(" getDatacenterId: " + e.getMessage());
}
return id;
}
/**
* 获取下一个ID
*
* @return
*/
public synchronized long nextId() {
long timestamp = timeGen();
//闰秒
if (timestamp < lastTimestamp) {
long offset = lastTimestamp - timestamp;
if (offset <= timestampOffset) {
try {
wait(offset << 1);
timestamp = timeGen();
if (timestamp < lastTimestamp) {
throw new RuntimeException(String.format("Clock moved backwards. Refusing to generate id for %d milliseconds", offset));
}
} catch (Exception e) {
throw new RuntimeException(e);
}
} else {
throw new RuntimeException(String.format("Clock moved backwards. Refusing to generate id for %d milliseconds", offset));
}
}
if (lastTimestamp == timestamp) {
// 相同毫秒内,序列号自增
sequence = (sequence + 1) & sequenceMask;
if (sequence == 0) {
// 同一毫秒的序列数已经达到最大
timestamp = tilNextMillis(lastTimestamp);
}
} else {
// 不同毫秒内,序列号置为 1 - 3 随机数
sequence = ThreadLocalRandom.current().nextLong(1, 3);
}
lastTimestamp = timestamp;
// 时间戳部分 | 数据中心部分 | 机器标识部分 | 序列号部分
return ((timestamp - twepoch) << timestampLeftShift)
| (datacenterId << datacenterIdShift)
| (workerId << workerIdShift)
| sequence;
}
protected long tilNextMillis(long lastTimestamp) {
long timestamp = timeGen();
while (timestamp <= lastTimestamp) {
timestamp = timeGen();
}
return timestamp;
}
protected long timeGen() {
return SystemClock.now();
}
}
package com.central.common.utils;
import java.util.UUID;
/**
* 短8位UUID思想其实借鉴微博短域名的生成方式,但是其重复概率过高,而且每次生成4个,需要随即选取一个。
*
* 本算法利用62个可打印字符,通过随机生成32位UUID,由于UUID都为十六进制,所以将UUID分成8组,每4个为一组,然后通过模62操作,
* 结果作为索引取出字符, 这样重复率大大降低。
*
* 经测试,在生成一千万个数据也没有出现重复,完全满足大部分需求。
*
* @author wangfan
* @date 2017-3-28 下午1:11:31
*/
public class UUIDUtil {
private UUIDUtil() {
throw new IllegalStateException("Utility class");
}
private static String[] chars = new String[] { "a", "b", "c", "d", "e", "f",
"g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s",
"t", "u", "v", "w", "x", "y", "z", "0", "1", "2", "3", "4", "5",
"6", "7", "8", "9", "A", "B", "C", "D", "E", "F", "G", "H", "I",
"J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",
"W", "X", "Y", "Z" };
/**
* 生成8位uuid
* @return
* @author wangfan
*/
public static String randomUUID8() {
StringBuilder shortBuffer = new StringBuilder();
String uuid = UUID.randomUUID().toString().replace("-", "");
for (int i = 0; i < 8; i++) {
String str = uuid.substring(i * 4, i * 4 + 4);
int x = Integer.parseInt(str, 16);
shortBuffer.append(chars[x % 0x3E]);
}
return shortBuffer.toString();
}
/**
* 生成32位uuid
* @return
* @author wangfan
*/
public static String randomUUID32(){
return UUID.randomUUID().toString().replace("-", "");
}
}
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