灰度发布
灰度发布分几种:蓝绿、ABTest以及金丝雀
灰度作用:为了减少灰度版本对生产环境的影响
灰度策略 | 内容 | 缺点 |
---|---|---|
蓝绿 | 会有两套环境,灰度发布之后,流量从绿切到蓝,然后进行验证 | 环境比较浪费,而且生产直接路由到灰度版本 |
ABTest | 在网关层对不同用户进行路由,只有特定用户切流量到灰度版本,这样的话不会影响生产用户 | 相对流量权重比较复杂,需要对用户进行区分对待 |
金丝雀 | 将部分流量切换过去,然后进行验证灰度的准确性,如果没有问题则流量全部切换 | 还是那个生产用户直接测试灰度版本 |
AB Test实践
逻辑架构图
这是第一版本,我们实现一个自定义loadBalance,filter拿到对应header头,或者说被动打标,通过不同的域名,来进行路由
流量路由的时候,基于nacos注册服务里面metaData标识,来决定路由到哪台服务
灰度测试完之后滚动更新生产pod
这个是外部访问内部,内部怎么访问外部?
fegin或者http请求,灰度版本服务通过域名来访问
dubbo请求,本身也有负载均衡器,需要拿到对应的标识,比如说版本号来负载
进阶第二版
在第一版我们自定义了loadBalance,以及路由标识,比如说网关配置lb:xxx,为啥是lb开头,大家可以看下ReactiveLoadBalancerClientFilter源码,我们其实是需要定义另一种标识
那么问题来了,当灰度测试完之后,负载怎么换成正常的lb?
这个涉及到网关route动态配置,publushEvent即可(这个不在本章介绍)
实现demo
参照另一篇文章
GrayGatewayReactiveLoadBalancerClientAutoConfiguration
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.cloud.client.loadbalancer.LoadBalancerProperties;
import org.springframework.cloud.loadbalancer.support.LoadBalancerClientFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
/**
* @author javachen
* @description GrayGatewayReactiveLoadBalancerClientAutoConfiguration
*/
@Configuration
public class GrayGatewayReactiveLoadBalancerClientAutoConfiguration {
public GrayGatewayReactiveLoadBalancerClientAutoConfiguration() {
}
@Bean
@ConditionalOnMissingBean({GrayReactiveLoadBalancerClientFilter.class})
public GrayReactiveLoadBalancerClientFilter grayReactiveLoadBalancerClientFilter(LoadBalancerClientFactory clientFactory, LoadBalancerProperties properties) {
return new GrayReactiveLoadBalancerClientFilter(clientFactory, properties);
}
}
GrayLoadBalancer
import org.apache.commons.lang3.ObjectUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.DefaultResponse;
import org.springframework.cloud.client.loadbalancer.EmptyResponse;
import org.springframework.cloud.client.loadbalancer.Request;
import org.springframework.cloud.client.loadbalancer.Response;
import org.springframework.cloud.loadbalancer.core.NoopServiceInstanceListSupplier;
import org.springframework.cloud.loadbalancer.core.ReactorServiceInstanceLoadBalancer;
import org.springframework.cloud.loadbalancer.core.ServiceInstanceListSupplier;
import org.springframework.http.HttpHeaders;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import java.util.*;
/**
* @author javachen
* @description GrayReactiveLoadBalancerClientFilter
*/
public class GrayLoadBalancer implements ReactorServiceInstanceLoadBalancer {
private static final Log log = LogFactory.getLog(GrayLoadBalancer.class);
private ObjectProvider<ServiceInstanceListSupplier> serviceInstanceListSupplierProvider;
private String serviceId;
public GrayLoadBalancer(ObjectProvider<ServiceInstanceListSupplier> serviceInstanceListSupplierProvider, String serviceId) {
this.serviceId = serviceId;
this.serviceInstanceListSupplierProvider = serviceInstanceListSupplierProvider;
}
@Override
public Mono<Response<ServiceInstance>> choose(Request request) {
HttpHeaders headers = (HttpHeaders) request.getContext();
if (this.serviceInstanceListSupplierProvider != null) {
ServiceInstanceListSupplier supplier = (ServiceInstanceListSupplier)this.serviceInstanceListSupplierProvider.getIfAvailable(NoopServiceInstanceListSupplier::new);
return ((Flux)supplier.get()).next().map(list->getInstanceResponse((List<ServiceInstance>)list,headers));
}
return null;
}
private Response<ServiceInstance> getInstanceResponse(List<ServiceInstance> instances, HttpHeaders headers) {
if (instances.isEmpty()) {
return getServiceInstanceEmptyResponse();
} else {
return getServiceInstanceResponseWithWeight(instances);
}
}
/**
* 根据版本进行分发
* @param instances
* @param headers
* @return
*/
private Response<ServiceInstance> getServiceInstanceResponseByVersion(List<ServiceInstance> instances, HttpHeaders headers) {
String versionNo = headers.getFirst("version");
//System.out.println(versionNo);
Map<String,String> versionMap = new HashMap<>();
versionMap.put("version",versionNo);
final Set<Map.Entry<String,String>> attributes =
Collections.unmodifiableSet(versionMap.entrySet());
ServiceInstance serviceInstance = null;
for (ServiceInstance instance : instances) {
Map<String,String> metadata = instance.getMetadata();
if(metadata.entrySet().containsAll(attributes)){
serviceInstance = instance;
break;
}
}
if(ObjectUtils.isEmpty(serviceInstance)){
return getServiceInstanceEmptyResponse();
}
return new DefaultResponse(serviceInstance);
}
/**
*
* 根据在nacos中配置的权重值,进行分发
* @param instances
*
* @return
*/
private Response<ServiceInstance> getServiceInstanceResponseWithWeight(List<ServiceInstance> instances) {
Map<ServiceInstance,Integer> weightMap = new HashMap<>();
for (ServiceInstance instance : instances) {
Map<String,String> metadata = instance.getMetadata();
//System.out.println(metadata.get("version")+"-->weight:"+metadata.get("weight"));
if(metadata.containsKey("gray")){
weightMap.put(instance,1000);
}else {
weightMap.put(instance,1);
}
}
WeightMeta<ServiceInstance> weightMeta = WeightRandomUtils.buildWeightMeta(weightMap);
if(ObjectUtils.isEmpty(weightMeta)){
return getServiceInstanceEmptyResponse();
}
ServiceInstance serviceInstance = weightMeta.random();
if(ObjectUtils.isEmpty(serviceInstance)){
return getServiceInstanceEmptyResponse();
}
return new DefaultResponse(serviceInstance);
}
private Response<ServiceInstance> getServiceInstanceEmptyResponse() {
log.warn("No servers available for service: " + this.serviceId);
return new EmptyResponse();
}
}
GrayReactiveLoadBalancerClientFilter
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.*;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.cloud.gateway.filter.ReactiveLoadBalancerClientFilter;
import org.springframework.cloud.gateway.support.DelegatingServiceInstance;
import org.springframework.cloud.gateway.support.NotFoundException;
import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;
import org.springframework.cloud.loadbalancer.core.ServiceInstanceListSupplier;
import org.springframework.cloud.loadbalancer.support.LoadBalancerClientFactory;
import org.springframework.core.Ordered;
import org.springframework.http.HttpHeaders;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;
import javax.servlet.http.HttpServletRequest;
import java.net.URI;
/**
* @author javachen
* @description GrayReactiveLoadBalancerClientFilter
*/
public class GrayReactiveLoadBalancerClientFilter implements GlobalFilter, Ordered {
private static final Log log = LogFactory.getLog(ReactiveLoadBalancerClientFilter.class);
private static final int LOAD_BALANCER_CLIENT_FILTER_ORDER = 10150;
private final LoadBalancerClientFactory clientFactory;
private LoadBalancerProperties properties;
public GrayReactiveLoadBalancerClientFilter(LoadBalancerClientFactory clientFactory, LoadBalancerProperties properties) {
this.clientFactory = clientFactory;
this.properties = properties;
}
@Override
public int getOrder() {
return LOAD_BALANCER_CLIENT_FILTER_ORDER;
}
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
URI url = (URI)exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR);
String schemePrefix = (String)exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_SCHEME_PREFIX_ATTR);
if (url != null && ("grayLb".equals(url.getScheme()) || "grayLb".equals(schemePrefix))) {
ServerWebExchangeUtils.addOriginalRequestUrl(exchange, url);
if (log.isTraceEnabled()) {
log.trace(ReactiveLoadBalancerClientFilter.class.getSimpleName() + " url before: " + url);
}
return this.choose(exchange).doOnNext((response) -> {
if (!response.hasServer()) {
throw NotFoundException.create(true, "Unable to find instance for " + url.getHost());
} else {
URI uri = exchange.getRequest().getURI();
String overrideScheme = null;
if (schemePrefix != null) {
overrideScheme = url.getScheme();
}
DelegatingServiceInstance serviceInstance = new DelegatingServiceInstance((ServiceInstance)response.getServer(), overrideScheme);
URI requestUrl = this.reconstructURI(serviceInstance, uri);
if (log.isTraceEnabled()) {
log.trace("LoadBalancerClientFilter url chosen: " + requestUrl);
}
exchange.getAttributes().put(ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR, requestUrl);
}
}).then(chain.filter(exchange));
} else {
return chain.filter(exchange);
}
}
protected URI reconstructURI(ServiceInstance serviceInstance, URI original) {
return LoadBalancerUriTools.reconstructURI(serviceInstance, original);
}
private Mono<Response<ServiceInstance>> choose(ServerWebExchange exchange) {
URI uri = (URI)exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR);
GrayLoadBalancer loadBalancer = new GrayLoadBalancer(clientFactory.getLazyProvider(uri.getHost(), ServiceInstanceListSupplier.class), uri.getHost());
if (loadBalancer == null) {
throw new NotFoundException("No loadbalancer available for " + uri.getHost());
} else {
return loadBalancer.choose(this.createRequest(exchange));
}
}
private Request createRequest(ServerWebExchange exchange) {
HttpHeaders headers = exchange.getRequest().getHeaders();
Request<HttpHeaders> request = new DefaultRequest<>(headers);
return request;
}
}
WeightMeta
import java.util.Arrays;
import java.util.Random;
/**
* @author javachen
* @description 权重元数据对象
*/
public class WeightMeta<T> {
private final Random ran = new Random();
private final T[] nodes;
private final int[] weights;
private final int maxW;
public WeightMeta(T[] nodes, int[] weights) {
this.nodes = nodes;
this.weights = weights;
this.maxW = weights[weights.length - 1];
}
/**
* 该方法返回权重随机对象
* @return
*/
public T random() {
int index = Arrays.binarySearch(weights, ran.nextInt(maxW) + 1);
if (index < 0) {
index = -1 - index;
}
return nodes[index];
}
public T random(int ranInt) {
if (ranInt > maxW) {
ranInt = maxW;
} else if(ranInt < 0){
ranInt = 1;
} else {
ranInt ++;
}
int index = Arrays.binarySearch(weights, ranInt);
if (index < 0) {
index = -1 - index;
}
return nodes[index];
}
@Override
public String toString() {
StringBuilder l1 = new StringBuilder();
StringBuilder l2 = new StringBuilder("[random]\t");
StringBuilder l3 = new StringBuilder("[node]\t\t");
l1.append(this.getClass().getName()).append(":").append(this.hashCode()).append(":\n").append("[index]\t\t");
for (int i = 0; i < weights.length; i++) {
l1.append(i).append("\t");
l2.append(weights[i]).append("\t");
l3.append(nodes[i]).append("\t");
}
l1.append("\n");
l2.append("\n");
l3.append("\n");
return l1.append(l2).append(l3).toString();
}
}
WeightRandomUtils
import java.util.HashMap;
import java.util.Map;
/**
* 权重算法取自:@see https://www.ctolib.com/topics-61571.html
*
* 随机工具类
*
* 使用权重的集合Map构建随机元数据对象
*
* 比如:
* 我们有3个url地址,他们的权重分别为1,2,3现在我们利用RandomUtil来根据权重随机获取url:
*
* <p><blockquote><pre>
*
* map.put(url1, 1);
* map.put(url2, 2);
* map.put(url3, 3);
* RandomMeta<String, Integer> md = WeightRandomUtils.buildWeightMeta(map);
* String weightRandomUrl = md.random();
*
* </pre></blockquote><p>
*
*
*/
public class WeightRandomUtils {
public static <T> WeightMeta<T> buildWeightMeta(final Map<T, Integer> weightMap) {
if(weightMap.isEmpty()){
return null;
}
final int size = weightMap.size();
Object[] nodes = new Object[size];
int[] weights = new int[size];
int index = 0;
int weightAdder = 0;
for (Map.Entry<T, Integer> each : weightMap.entrySet()) {
nodes[index] = each.getKey();
weights[index++] = (weightAdder = weightAdder + each.getValue());
}
return new WeightMeta<T>((T[]) nodes, weights);
}
public static void main(String[] args) {
Map<String,Integer> map = new HashMap<>();
map.put("v1",1);
map.put("v2",2);
WeightMeta<String> nodes = WeightRandomUtils.buildWeightMeta(map);
for(int i = 0; i < 10; i++){
new Thread(()->{
System.out.println(nodes.random());
}).start();
}
}
}
解析
可以参照ReactiveLoadBalancerClientFilter,RoundRobinLoadBalancer
就是里面会调用choose方法来进行负载
关键修改点
GrayLoadBalancer
启动这个,根据用户header以及访问host域名来触发
实践
nacos 两个实例,不同版本,元数据
postman带上特定标识,调接口的时候会发现进入了灰度版本
优化点
灰度测试后,不改负载也可以,最好是可以改回正常的负载
所以进行网关路由的动态配置,有很多实现方法
ReactiveLoadBalancerClientFilter源码
- GlobalFilter, Ordered ReactiveLoadBalancerClientFilter实现这两个类,搞过网关(网关是谁)的都知道,这两就是过滤器+排序
- 为啥网关配置是按lb开头?
- 关键点,是在choose方法,ReactorLoadBalancer负载算法,决定要路由到哪台机器
- ReactorLoadBalancer源码 (RoundRobinLoadBalancer实现类)
- 路由算法(这就是为啥前面我们会实现GrayLoadBalancer,WeightRandomUtils,就是仿造之前的RoundRobinLoadBalancer)