【云原生 | Envoy 系列】--Envoy负载均衡调度机制

企业开发 2022-10-25 01:01:48 阅读次数: 0

1. 节点优先级

属于某个特定位置的一组端点被称为LLE或LLBE(LocalityLBEndpoints),它们具有相同的位置(locality),权重(load_balancing_weight)和优先级(priority)

  • locality: 从大到小分别是region(地域),zone(区域)sub_zone(子区域)进行逐级标识
  • load_balancing_weight可以对每个priority/region/zone/sub_zone配置权重,取值范围[1,n),通常一个locality权重除以具有相同的优先级的所有locality的权重之和即为当前locality的流量比例
  • priority此LocalityLbEndpoints组的优先级,默认为最高优先级0

通常Envoy调度时仅挑选最高优先级的一组Endpoint,且仅此优先级的所有端点均不可用时才进行故障转移至下一个优先级的相关端点.

也可以在同个位置配置多个LbEndpoints,但这通常仅在不同组需要具有不同的负载均衡权重或不同的优先级时才需要

2. 优先级调度

调度时,Envoy仅将流量调度至最高优先级的一组端点(LocalityLbEndpoints)

- 最高优先级不健康时,流量发生转移.
- 可以在一组端点中设置超配因子,实现部分端点故障时仍将更大比例的流量导向本组端点.

优先级调度支持同一优先级内部的端点降级(DEGRADED)机制,其工作方式类同于在两个不同优先级之间的端点分配流量的机制

3. Panic恐慌阈值

调度期间Envoy仅考虑上游主机列表中的可用(健康)端点,但可用端点的百分比过低时,Envoy将忽略所有端点的健康状态并将流量调度给所有端点;此百分比即为Panic阈值,也称恐慌阈值.

	- 默认Panic阈值是50%
	- Panic阈值用于避免在流量增长时导致主机故障进入级联状态

例如: Endpoints一共10个节点,当其中的6个节点异常时,就触发了恐慌阈值(50%),此时进来700个请求,就会被调度到所有的Endpoints 10个节点,即正常的4个节点负责响应40%的流量,6个异常节点负责60%的流量,这样就会造成60%的访问是异常的,但保证了有40%的访问是正常的.避免了全部流量压在4台ep上造成雪崩的发生.

恐慌阈值可以与优先级一同使用

给定优先级中的可用端点数量下降时,Envoy会将一些流量转移给较低优先级的端点.

	- 若第一级的端点能承载所有流量时,忽略恐慌阈值
	- 否则,Envoy会在所有优先级之间分配流量,并在给定的优先级的可用性低于恐慌阈值时将该优先级的流量分配至该优先级所有主机

# Cluster.CommonLbConfig
{
    
    
"healthy_panic_threshold": "{...}",     # 百分比数值,定义恐慌阈值,默认为50%
"zone_aware_lb_config": "{...}",
"locality_weighted_lb_config": "{...}",
"update_merge_window": "{...}",
"ignore_new_hosts_until_first_hc": "..."
}

4. Priority levels测试

4.1 docker-compose

一共11个container:

  1. envoy：Front Proxy,地址为172.31.29.2
  • webserver01：第一个后端服务
  • webserver01-sidecar：第一个后端服务的Sidecar Proxy,地址为172.31.29.11, 别名为red和webservice1
  • webserver02：第二个后端服务
  • webserver02-sidecar：第一个后端服务的Sidecar Proxy,地址为172.31.29.12, 别名为blue和webservice1
  • webserver03：第三个后端服务
  • webserver03-sidecar：第一个后端服务的Sidecar Proxy,地址为172.31.29.13, 别名为green和webservice1
  • webserver04：第四个后端服务
  • webserver04-sidecar：第四个后端服务的Sidecar Proxy,地址为172.31.29.14, 别名为gray和webservice2
  • webserver05：第五个后端服务
  • webserver05-sidecar：第五个后端服务的Sidecar Proxy,地址为172.31.29.15, 别名为black和webservice2
version: '3'

services:
  front-envoy:
    image: envoyproxy/envoy-alpine:v1.13-latest
    volumes:
      - ./front-envoy-v2.yaml:/etc/envoy/envoy.yaml
    networks:
      - envoymesh
    expose:
      # Expose ports 80 (for general traffic) and 9901 (for the admin server)
      - "80"
      - "9901"
  webserver01-sidecar:
    image: envoyproxy/envoy-alpine:v1.21.5
    volumes:
    - ./envoy-sidecar-proxy.yaml:/etc/envoy/envoy.yaml
    hostname: red
    networks:
      envoymesh:
        ipv4_address: 172.31.29.11
        aliases:
        - webservice1
        - red

  webserver01:
    image: ikubernetes/demoapp:v1.0
    environment:
      - PORT=8080
      - HOST=127.0.0.1
    network_mode: "service:webserver01-sidecar"
    depends_on:
    - webserver01-sidecar

  webserver02-sidecar:
    image: envoyproxy/envoy-alpine:v1.21.5
    volumes:
    - ./envoy-sidecar-proxy.yaml:/etc/envoy/envoy.yaml
    hostname: blue
    networks:
      envoymesh:
        ipv4_address: 172.31.29.12
        aliases:
        - webservice1
        - blue

  webserver02:
    image: ikubernetes/demoapp:v1.0
    environment:
      - PORT=8080
      - HOST=127.0.0.1
    network_mode: "service:webserver02-sidecar"
    depends_on:
    - webserver02-sidecar

  webserver03-sidecar:
    image: envoyproxy/envoy-alpine:v1.21.5
    volumes:
    - ./envoy-sidecar-proxy.yaml:/etc/envoy/envoy.yaml
    hostname: green
    networks:
      envoymesh:
        ipv4_address: 172.31.29.13
        aliases:
        - webservice1
        - green

  webserver03:
    image: ikubernetes/demoapp:v1.0
    environment:
      - PORT=8080
      - HOST=127.0.0.1
    network_mode: "service:webserver03-sidecar"
    depends_on:
    - webserver03-sidecar

  webserver04-sidecar:
    image: envoyproxy/envoy-alpine:v1.21.5
    volumes:
    - ./envoy-sidecar-proxy.yaml:/etc/envoy/envoy.yaml
    hostname: gray
    networks:
      envoymesh:
        ipv4_address: 172.31.29.14
        aliases:
        - webservice2
        - gray

  webserver04:
    image: ikubernetes/demoapp:v1.0
    environment:
      - PORT=8080
      - HOST=127.0.0.1
    network_mode: "service:webserver04-sidecar"
    depends_on:
    - webserver04-sidecar

  webserver05-sidecar:
    image: envoyproxy/envoy-alpine:v1.21.5
    volumes:
    - ./envoy-sidecar-proxy.yaml:/etc/envoy/envoy.yaml
    hostname: black
    networks:
      envoymesh:
        ipv4_address: 172.31.29.15
        aliases:
        - webservice2
        - black

  webserver05:
    image: ikubernetes/demoapp:v1.0
    environment:
      - PORT=8080
      - HOST=127.0.0.1
    network_mode: "service:webserver05-sidecar"
    depends_on:
    - webserver05-sidecar

networks:
  envoymesh:
    driver: bridge
    ipam:
      config:
        - subnet: 172.31.29.0/24

4.2 envoy.yaml

  1. 对每个service的/livez进行健康检查,返回如果不是OK就认为失败.
  2. 两个集群cn-north-1和cn-north-2,cn-north-1优先级是0,cn-north-2优先级是1.所以当cn-north-1全部正常的情况下cn-north-2不分担流量
admin:
  access_log_path: "/dev/null"
  address:
    socket_address:
      address: 0.0.0.0
      port_value: 9901

static_resources:
  listeners:
  - address:
      socket_address:
        address: 0.0.0.0
        port_value: 80
    name: listener_http
    filter_chains:
    - filters:
      - name: envoy.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.config.filter.network.http_connection_manager.v2.HttpConnectionManager
          codec_type: auto
          stat_prefix: ingress_http
          route_config:
            name: local_route
            virtual_hosts:
            - name: backend
              domains:
              - "*"
              routes:
              - match:
                  prefix: "/"
                route:
                  cluster: webcluster1
          http_filters:
          - name: envoy.router

  clusters:
  - name: webcluster1
    connect_timeout: 0.5s
    type: STRICT_DNS
    lb_policy: ROUND_ROBIN
    http2_protocol_options: {
    
    }
    load_assignment:
      cluster_name: webcluster1
      policy:
        overprovisioning_factor: 140
      endpoints:
      - locality:
          region: cn-north-1
        priority: 0
        lb_endpoints:
        - endpoint:
            address:
              socket_address:
                address: webservice1
                port_value: 80
      - locality:
          region: cn-north-2
        priority: 1
        lb_endpoints:
        - endpoint:
            address:
              socket_address:
                address: webservice2
                port_value: 80
    health_checks:
    - timeout: 5s
      interval: 10s
      unhealthy_threshold: 2
      healthy_threshold: 1
      http_health_check:
        path: /livez

4.3 部署测试

此时由于cn-north-1的3台服务器都正常,所以由cn-north-1的服务器响应所有请求

扫描二维码关注公众号，回复： 14542698 查看本文章 
# docker-compose
root@k8s-node-1:~# while true; do curl 172.31.29.2;sleep 0.5 ;done
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: blue, ServerIP: 172.31.29.12!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: blue, ServerIP: 172.31.29.12!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: red, ServerIP: 172.31.29.11!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: blue, ServerIP: 172.31.29.12!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: red, ServerIP: 172.31.29.11!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: red, ServerIP: 172.31.29.11!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: blue, ServerIP: 172.31.29.12!

4.4 触发异常

  1. 当将cn-north-1中的服务器172.31.29.12/livez设置为非OK状态,此时触发健康检查失败,返回值506
  2. 当连续3次506后,故障节点172.31.29.12被标记为不可用,不再将流量转发至172.31.29.12
  3. 此时cn-north-1可用率是66.66%,乘以1.4的超配因子(overprovisioning_factor),此时93.324%的流量由cn-north-1负载,其余6.676%的流量由cn-north-2负担.所以此时会看到172.31.29.14,172.31.29.15进行响应
root@k8s-node-1:~# curl -XPOST -d "livez=FAIL" 172.31.29.12/livez

webserver01_1          | 127.0.0.1 - - [29/Sep/2022 03:59:13] "GET / HTTP/1.1" 200 -
webserver05_1          | 127.0.0.1 - - [29/Sep/2022 03:59:13] "GET /livez HTTP/1.1" 200 -
webserver04_1          | 127.0.0.1 - - [29/Sep/2022 03:59:13] "GET /livez HTTP/1.1" 200 -
webserver02_1          | 127.0.0.1 - - [29/Sep/2022 03:59:13] "GET /livez HTTP/1.1" 506 -
webserver01_1          | 127.0.0.1 - - [29/Sep/2022 03:59:13] "GET /livez HTTP/1.1" 200 -
webserver01_1          | 127.0.0.1 - - [29/Sep/2022 03:59:13] "GET / HTTP/1.1" 200 -
# 经过3次506之后就会有一定几率往14和15进行流量的调度
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: red, ServerIP: 172.31.29.11!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: red, ServerIP: 172.31.29.11!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: gray, ServerIP: 172.31.29.14!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
...
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: red, ServerIP: 172.31.29.11!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: red, ServerIP: 172.31.29.11!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: black, ServerIP: 172.31.29.15!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!

4.5 恢复

此时cn-north-1恢复到100%状态,由cn-north-1的服务器响应所有请求,cn-north-2不再参与响应.

root@k8s-node-1:~# curl -XPOST -d "livez=OK" 172.31.29.12/livez
webserver02_1          | 127.0.0.1 - - [29/Sep/2022 04:01:46] "GET / HTTP/1.1" 200 -
webserver01_1          | 127.0.0.1 - - [29/Sep/2022 04:01:47] "GET / HTTP/1.1" 200 -
webserver03_1          | 127.0.0.1 - - [29/Sep/2022 04:01:47] "GET / HTTP/1.1" 200 -
webserver01_1          | 127.0.0.1 - - [29/Sep/2022 04:01:48] "GET / HTTP/1.1" 200 -
webserver02_1          | 127.0.0.1 - - [29/Sep/2022 04:01:48] "GET / HTTP/1.1" 200 -
webserver01_1          | 127.0.0.1 - - [29/Sep/2022 04:01:49] "GET / HTTP/1.1" 200 -
## 此时流量又恢复到原先11.12.13上
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: red, ServerIP: 172.31.29.11!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: red, ServerIP: 172.31.29.11!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: blue, ServerIP: 172.31.29.12!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: red, ServerIP: 172.31.29.11!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: green, ServerIP: 172.31.29.13!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: blue, ServerIP: 172.31.29.12!
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.1, ServerName: blue, ServerIP: 172.31.29.12!

5. 位置加权负载均衡

位置加权负载均衡(Locality weighted load balancing)即为特定Locality及相关LbEndpoints组显示赋予权重,并根据此权重比在各Locality之间分配流量.

  • 所有locality均可用时,则根据位置权重在各locality之间进行加权轮询
  • 位置权重负载均衡同区域感知负载均衡互斥,因此,用户仅可在Cluster级别设置locality_weighted_lb_config或zone_aware_lb_config其中之一,以明确启用的负载均衡策略
cluster:
- name:
  ...
  common_lb_config:
  locality_weighted_lb_config: {
    
    } # 启用位置加权负载均衡机制,它没有可用的子参数
  ...
load_assignment:
  endpoints:
    locality: "{...}"
    lb_endpoints: "[]"
    load_balancing_weight: "{}" #整数值,定义当前位置或优先级的权重,最小值为1
    priority: "..."
  • 当某个Locality的某些Endpoints不可用时,Envoy按比例动态调整该Locality的权重
  • 若同时配置了优先级和权重,负载均衡器会先选择priority,再从priority中选择locality;最后再locality中选择endpoint

6. 负载均衡子集(subset)

6.1 子集和元数据

Envoy还支持一个集群中基于子集实现更细粒度的流量分发

  • 首先,在集群的上游主机上添加元数据(键值标签),并使用子集选择器(分类元数据)将上游主机划分为子集
  • 在路由配置中指定负载均衡器可以选择的且必须具有匹配的元数据的上游主机,从而实现向特定子集的路由.
  • 各子集内的主机间的负载均衡采用集群定义的策略(lb_policy)

配置了子集,但路由并未指定元数据或不存在与指定元数据匹配的子集时,则子集均衡器为其应用"回退策略"

  • NO_FALLBACK: 请求失败,类似集群中不存在任何主机;默认
  • ANY_ENDPOINT: 所有主机间进行调度,不再考虑主机元数据
  • DEFAULT_SUBSET:调度至默认的子集,该子集需要事先定义.

子集必须预定义才能由子集负载均衡器在调度时使用.
子集元数据是键值数据,且必须定义在envoy.lb过滤器之下.

元数据示例:

load_assignment:
  cluster_name: webcluster1
  endpoints:
  - lb_endpoints:
    - endpoint:
      address:
        socket_address:
        protocol: TCP
        address: ep1
        port_value: 80
      metadata:
        filter_metadata:
          envoy.lb:
            version: '1.0'
            stage: 'prod'

6.2 子集

子集示例:

clusters:
- name: ...
...
  lb_subset_config:
    fallback_policy: "..."  # 回退策略,默认为NO_FALLBACK
    default_subset: "{...}" # 回退策略DEFAULT_SUBSET使用的默认子集
    subset_selectors: [] # 子集选择器
    - keys: [] # 定义一个选择器,指定用于归类主机元数据的键列表,可以是值或是表达式
      fallback_policy: ... # 当前选择器专用的回退策略.
    locality_weight_aware: "..." # 是否在将请求路由到子集时考虑端点的位置和位置权重,存在一些潜在的缺陷
    scale_locality_weight: "..." # 是否将子集与主机中的主机比率来缩放每个位置权重
    panic_mode_any: "..." # 是否在配置回退策略且其相应的子集无法找到主机时尝试从整个集群中选择主机
    list_as_any: "..." # 列出主机
  • 对于每个选择器,Envoy会遍历主机并检查其"envoy.lb"过滤器元数据,并为每个唯一的键值组合创建一个子集
  • 若某主机元数据可以匹配该选择器中指定每个键,则会将该主机添加至此选择器中.这同时意味着,一个主机可能同时满足多个子集选择器的适配条件,此时该主机将同时隶属于多个子集
  • 若所有主机均未定义元数据,则不会生成任何子集.

6.3 路由元数据匹配(metadata_match)

使用负载均衡器子集还要求在路由条目上配置元数据匹配(metadata_match)条件,它用于在路由期间查找特定子集

  • 仅在上游集群中与metadata_match中设置的元数据匹配的子集时才能完成流量路由
  • 使用weighted_cluster定义路由目标时,其内部的各目标集群也可以定义专用metadata_match
routes:
- name: ...
  metach: {
    
    ...}
  route: {
    
    ...}
    cluster:
    metadata_match: {
    
    ...} # 子集负载均衡器使用的端点元数据匹配条件,若使用了weighted_clusters且内部定义了metadata_match,
    				# 则元数据将被合并,且weighted_cluster中定义的值优先,过滤器名称指定为envoy.lb
      filter_metadata: {
    
    ...}
        envoy.lb: {
    
    ...}
          key1: value1
          key2: value2
          ...
    weighted_clusters: {
    
    ...}
      clusters: []
      - name: ...
        weight: ...
        metadata_match: {
    
    ...}

不存在与路由元数据匹配的子集时,将启用回退策略,就是发给默认的集群

6.4 docker-compose

一共 8 个container:

  • Front Proxy: 地址为172.31.33.2
  • webserver01：第一个后端服务地址为172.31.33.11,stage: “prod”,version: “1.0”,type: “std”,xlarge: true
  • webserver02：第一个后端服务地址为172.31.33.12,stage: “prod”,version: “1.0”,type: “std”
  • webserver03：第一个后端服务地址为172.31.33.13,stage: “prod”,version: “1.1”,type: “std”
  • webserver04：第一个后端服务地址为172.31.33.14,stage: “prod”,version: “1.1”,type: “std”
  • webserver05：第一个后端服务地址为172.31.33.15,stage: “prod”,version: “1.0”,type: “bigmem”
  • webserver06：第一个后端服务地址为172.31.33.16,stage: “prod”,version: “1.1”,type: “bigmem”
  • webserver07：第一个后端服务地址为172.31.33.17,stage: “dev”,version: “1.2-pre”,type: “std”

请添加图片描述

version: '3'

services:
  front-envoy:
    image: envoyproxy/envoy-alpine:v1.21.5
    volumes:
      - ./front-envoy.yaml:/etc/envoy/envoy.yaml
    networks:
      envoymesh:
        ipv4_address: 172.31.33.2
    expose:
      # Expose ports 80 (for general traffic) and 9901 (for the admin server)
      - "80"
      - "9901"

  e1:
    image: ikubernetes/demoapp:v1.0
    hostname: e1
    networks:
      envoymesh:
        ipv4_address: 172.31.33.11
        aliases:
          - e1
    expose:
      - "80"

  e2:
    image: ikubernetes/demoapp:v1.0
    hostname: e2
    networks:
      envoymesh:
        ipv4_address: 172.31.33.12
        aliases:
          - e2
    expose:
      - "80"

  e3:
    image: ikubernetes/demoapp:v1.0
    hostname: e3
    networks:
      envoymesh:
        ipv4_address: 172.31.33.13
        aliases:
          - e3
    expose:
      - "80"

  e4:
    image: ikubernetes/demoapp:v1.0
    hostname: e4
    networks:
      envoymesh:
        ipv4_address: 172.31.33.14
        aliases:
          - e4
    expose:
      - "80"

  e5:
    image: ikubernetes/demoapp:v1.0
    hostname: e5
    networks:
      envoymesh:
        ipv4_address: 172.31.33.15
        aliases:
          - e5
    expose:
      - "80"

  e6:
    image: ikubernetes/demoapp:v1.0
    hostname: e6
    networks:
      envoymesh:
        ipv4_address: 172.31.33.16
        aliases:
          - e6
    expose:
      - "80"

  e7:
    image: ikubernetes/demoapp:v1.0
    hostname: e7
    networks:
      envoymesh:
        ipv4_address: 172.31.33.17
        aliases:
          - e7
    expose:
      - "80"

networks:
  envoymesh:
    driver: bridge
    ipam:
      config:
        - subnet: 172.31.33.0/24

6.5 envoy.yaml

admin:
  access_log_path: "/dev/null"
  address:
    socket_address: {
    
     address: 0.0.0.0, port_value: 9901 }

static_resources:
  listeners:
  - address:
      socket_address: {
    
     address: 0.0.0.0, port_value: 80 }
    name: listener_http
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          codec_type: auto
          stat_prefix: ingress_http
          route_config:
            name: local_route
            virtual_hosts:
            - name: backend
              domains:
              - "*"
              routes:
              - match:
                  prefix: "/"
                  headers:
                  - name: x-custom-version
                    exact_match: pre-release
                route:
                  cluster: webcluster1
                  metadata_match:
                    filter_metadata:
                      envoy.lb:
                        version: "1.2-pre"
                        stage: "dev"
              - match:
                  prefix: "/"
                  headers:
                  - name: x-hardware-test
                    exact_match: memory
                route:
                  cluster: webcluster1
                  metadata_match:
                    filter_metadata:
                      envoy.lb:
                        type: "bigmem"
                        stage: "prod"
              - match:
                  prefix: "/"
                route:
                  weighted_clusters:
                    clusters:
                    - name: webcluster1
                      weight: 90
                      metadata_match:
                        filter_metadata:
                          envoy.lb:
                            version: "1.0"
                    - name: webcluster1
                      weight: 10
                      metadata_match:
                        filter_metadata:
                          envoy.lb:
                            version: "1.1"
                  metadata_match:
                    filter_metadata:
                      envoy.lb:
                        stage: "prod"
          http_filters:
          - name: envoy.filters.http.router

  clusters:
  - name: webcluster1
    connect_timeout: 0.5s
    type: STRICT_DNS
    lb_policy: ROUND_ROBIN
    load_assignment:
      cluster_name: webcluster1
      endpoints:
      - lb_endpoints:
        - endpoint:
            address:
              socket_address:
                address: e1
                port_value: 80
          metadata:
            filter_metadata:
              envoy.lb:
                stage: "prod"
                version: "1.0"
                type: "std"
                xlarge: true
        - endpoint:
            address:
              socket_address:
                address: e2
                port_value: 80
          metadata:
            filter_metadata:
              envoy.lb:
                stage: "prod"
                version: "1.0"
                type: "std"
        - endpoint:
            address:
              socket_address:
                address: e3
                port_value: 80
          metadata:
            filter_metadata:
              envoy.lb:
                stage: "prod"
                version: "1.1"
                type: "std"
        - endpoint:
            address:
              socket_address:
                address: e4
                port_value: 80
          metadata:
            filter_metadata:
              envoy.lb:
                stage: "prod"
                version: "1.1"
                type: "std"
        - endpoint:
            address:
              socket_address:
                address: e5
                port_value: 80
          metadata:
            filter_metadata:
              envoy.lb:
                stage: "prod"
                version: "1.0"
                type: "bigmem"
        - endpoint:
            address:
              socket_address:
                address: e6
                port_value: 80
          metadata:
            filter_metadata:
              envoy.lb:
                stage: "prod"
                version: "1.1"
                type: "bigmem"
        - endpoint:
            address:
              socket_address:
                address: e7
                port_value: 80
          metadata:
            filter_metadata:
              envoy.lb:
                stage: "dev"
                version: "1.2-pre"
                type: "std"
    lb_subset_config:
      fallback_policy: DEFAULT_SUBSET            
      default_subset:
        stage: "prod"
        version: "1.0"
        type: "std"
      subset_selectors:
      - keys: ["stage", "type"]
      - keys: ["stage", "version"]
      - keys: ["version"]
      - keys: ["xlarge", "version"]
    health_checks:
    - timeout: 5s
      interval: 10s
      unhealthy_threshold: 2
      healthy_threshold: 1
      http_health_check:
        path: /livez
        expected_statuses:
          start: 200
          end: 399

6.6 部署测试

# docker-compose up

6.6.1 权重测试

由于envoy.yaml中对标签权重设置

                    - name: webcluster1
                      weight: 90
                      metadata_match:
                        filter_metadata:
                          envoy.lb:
                            version: "1.0"
                    - name: webcluster1
                      weight: 10
                      metadata_match:
                        filter_metadata:
                          envoy.lb:
                            version: "1.1"

当执行以下脚本时,就会产生9:1的访问比例

# cat test.sh 
#!/bin/bash
declare -i v10=0
declare -i v11=0

for ((counts=0; counts<200; counts++)); do
	if curl -s http://$1/hostname | grep -E "e[125]" &> /dev/null; then
		# $1 is the host address of the front-envoy.
		v10=$[$v10+1]
	else
		v11=$[$v11+1]
	fi
done

echo "Requests: v1.0:v1.1 = $v10:$v11"
# ./test.sh 172.31.33.2
Requests: v1.0:v1.1 = 183:17
# ./test.sh 172.31.33.2
Requests: v1.0:v1.1 = 184:16
# ./test.sh 172.31.33.2
Requests: v1.0:v1.1 = 184:16
# ./test.sh 172.31.33.2
Requests: v1.0:v1.1 = 180:20

6.6.2 子集测试1

当以header x-hardware-test: memory访问时就会根据envoy.yaml中的以下配置进行选择type: “bigmem”,stage: "prod"的subset
即E5和E6

              - match:
                  prefix: "/"
                  headers:
                  - name: x-hardware-test
                    exact_match: memory
                route:
                  cluster: webcluster1
                  metadata_match:
                    filter_metadata:
                      envoy.lb:
                        type: "bigmem"
                        stage: "prod"

root@k8s-node-1:~# curl -H "x-hardware-test: memory" 172.31.33.2/hostname
ServerName: e5
root@k8s-node-1:~# curl -H "x-hardware-test: memory" 172.31.33.2/hostname
ServerName: e5
root@k8s-node-1:~# curl -H "x-hardware-test: memory" 172.31.33.2/hostname
ServerName: e6
root@k8s-node-1:~# curl -H "x-hardware-test: memory" 172.31.33.2/hostname
ServerName: e5
root@k8s-node-1:~# curl -H "x-hardware-test: memory" 172.31.33.2/hostname
ServerName: e6
root@k8s-node-1:~# curl -H "x-hardware-test: memory" 172.31.33.2/hostname
ServerName: e6

请添加图片描述

6.6.3 子集测试2

当以header x-custom-version: pre-release访问时会根据标签选择version: “1.2-pre”,stage: "dev"的后端subset,即e7

              - match:
                  prefix: "/"
                  headers:
                  - name: x-custom-version
                    exact_match: pre-release
                route:
                  cluster: webcluster1
                  metadata_match:
                    filter_metadata:
                      envoy.lb:
                        version: "1.2-pre"
                        stage: "dev"

root@k8s-node-1:~# curl -H "x-custom-version: pre-release" 172.31.33.2/hostname
ServerName: e7
root@k8s-node-1:~# curl -H "x-custom-version: pre-release" 172.31.33.2/hostname
ServerName: e7
root@k8s-node-1:~# curl -H "x-custom-version: pre-release" 172.31.33.2/hostname
ServerName: e7
root@k8s-node-1:~# curl -H "x-custom-version: pre-release" 172.31.33.2/hostname
ServerName: e7
root@k8s-node-1:~# curl -H "x-custom-version: pre-release" 172.31.33.2/hostname
ServerName: e7
root@k8s-node-1:~# curl -H "x-custom-version: pre-release" 172.31.33.2/hostname
ServerName: e7

请添加图片描述

6.6.4 子集测试3

预想将配置改为选择 E1 E2 E3 E4这组的subset

请添加图片描述

那么就需要修改envoy实现新增一组基于子集的标签选择
stage=prod,type=std

              - match:
                  prefix: "/"
                  headers:
                  - name: prod-type                                                                             
                    exact_match: std
                route:
                  cluster: webcluster1
                  metadata_match:
                    filter_metadata:
                      envoy.lb:
                        stage: "prod"
                        type: "std"

效果如下:

root@k8s-node-1:~# curl -H "prod-type: std" 172.31.33.2/hostname
ServerName: e1
root@k8s-node-1:~# curl -H "prod-type: std" 172.31.33.2/hostname
ServerName: e1
root@k8s-node-1:~# curl -H "prod-type: std" 172.31.33.2/hostname
ServerName: e2
root@k8s-node-1:~# curl -H "prod-type: std" 172.31.33.2/hostname
ServerName: e1
root@k8s-node-1:~# curl -H "prod-type: std" 172.31.33.2/hostname
ServerName: e2
root@k8s-node-1:~# curl -H "prod-type: std" 172.31.33.2/hostname
ServerName: e3
root@k8s-node-1:~# curl -H "prod-type: std" 172.31.33.2/hostname
ServerName: e2
root@k8s-node-1:~# curl -H "prod-type: std" 172.31.33.2/hostname
ServerName: e3

6.6.5 子集测试4

只选择有E1的子集

              - match:
                  prefix: "/"
                  headers:
                  - name: subset
                    exact_match: endpoint
                route:
                  cluster: webcluster1
                  metadata_match:
                    filter_metadata:
                      envoy.lb:
                        version: "1.0"
                        xlarge: true

测试效果

root@k8s-node-1:~# curl -H "subset: endpoint" 172.31.33.2/hostname
ServerName: e1
root@k8s-node-1:~# curl -H "subset: endpoint" 172.31.33.2/hostname
ServerName: e1
root@k8s-node-1:~# curl -H "subset: endpoint" 172.31.33.2/hostname
ServerName: e1
root@k8s-node-1:~# curl -H "subset: endpoint" 172.31.33.2/hostname
ServerName: e1
root@k8s-node-1:~# curl -H "subset: endpoint" 172.31.33.2/hostname
ServerName: e1

猜你喜欢

转载自blog.csdn.net/qq_29974229/article/details/127238383
今日推荐
TIOBE 5 月榜单：Fortran “复活”进入 Top 10
GCC 14.1 发布
面壁智能发布 Eurux-8x22B 开源大模型 —— 堪称「理科状元」
开源日报 | 谷歌扶持鸿蒙上位；开源Rabbit R1；Docker加持的安卓手机；微软的焦虑和野心；海尔电器把开放平台关了
中国码农的“35岁魔咒”
蘭雅 CorelDRAW 插件 2024.5.1 国际劳动节版，免费下载
Arc Browser for Windows 1.0 正式 GA
90后程序员开发视频搬运软件、不到一年获利超 700 万，结局很刑！
周排行
基本数据类型封装类比较 Java源码解读(一) 8种基本类型对应的封装类型
JS实现无缝滚动上
深入解析HashMap原理（基于JDK1.8）
mysql的连接池
关于.htc
linux下的ubuntu12.04图形界面
【数论】好推不好记的扩展欧几里德
设备树详解
cscope + tags 简单设置
xml学习
每日归档
更多
2024-05-09(35)
2024-05-08(42)
2024-05-07(14)
2024-05-06(40)
2024-05-05(0)
2024-05-04(7)
2024-05-03(19)
2024-05-02(0)
2024-05-01(4)
2024-04-30(1)

代码天地 © 2018 codetd.com

境外服务器   最新电视剧2022