ASMAdaptiveConcurrency能够根据采样的请求数据动态调整允许的并发的数量,当并发数量超过服务可承受范围时,会拒绝请求,达到保护服务的目的。本文介绍如何使用ASMAdaptiveConcurrency实现自适应并发控制。

前提条件

  • 已创建高级版或旗舰版ASM实例,且实例为1.12.4.19或以上版本。具体操作,请参见创建ASM实例
  • 添加集群到ASM实例。具体操作,请参见添加集群到ASM实例

背景信息

通常情况下,希望服务在超出负载能力时能拒绝超额的请求,从而防止产生其他连锁反应。您可以使用服务网格的DestinationRule配置基础的熔断能力,但这要求必须给出一个触发熔断的阈值,例如具体的pending requests数量,使得服务网格数据平面在网络访问超出熔断配置时能够拒绝请求。在实际应用场景下,准确地估算服务的负载能力是较为困难的。

ASMAdaptiveConcurrency采用自适应并发控制算法通过定期对比采样Latency和测定的理想Latency之间的差异及一系列计算对并发限制进行动态调整,从而尽可能使得并发限制数量在服务可承受的范围附近,同时拒绝超出该限制的请求(拒绝请求时会返回HTTP 503及错误信息reached concurrency limit)。

由于周期性的MinRTT统计进行期间会将连接数限制在较小值(min_concurrency),建议您在启用了AdaptiveConcurrency服务后,同时使用DestinationRule为服务启用重试功能,使得在minRTT计算期间被拒绝的请求能够通过Sidecar的重试功能尽可能地成功返回结果。

步骤一:部署示例应用

部署testserver和gotest应用,设置testserver应用的负载能力为并发处理500个请求,超过并发数量的请求会被排队处理。每个请求的处理时间是1000ms。设置gotest应用的一个副本一次能发起200个请求。

  1. 通过kubectl工具连接集群
  2. 部署testserver应用。
    1. 使用以下内容,创建testserver.yaml文件。

      展开查看详细内容

      apiVersion: apps/v1
      kind: Deployment
      metadata:
        labels:
          app: testserver
        name: testserver
        namespace: default
      spec:
        replicas: 1
        selector:
          matchLabels:
            app: testserver
        template:
          metadata:
            creationTimestamp: null
            labels:
              app: testserver
          spec:
            containers:
            - args:
              - -m
              - "500"
              - -t
              - "1000"
              command:
              - /usr/local/bin/limited-concurrency-http-server
              image: registry.cn-hangzhou.aliyuncs.com/acs/asm-limited-concurrency-http-server:v0.1.1-gee0b08f-aliyun
              imagePullPolicy: IfNotPresent
              name: testserver
              ports:
              - containerPort: 8080
                protocol: TCP

      您可以使用-m指定应用能够承受的并发数量,-t指定请求处理时间。

    2. 执行以下命令,部署testserver应用。
      kubectl apply -f testserver.yaml
  3. 部署testserver的Service。
    1. 使用以下内容,创建testservice.yaml文件。

      展开查看详细内容

      apiVersion: v1
      kind: Service
      metadata:
        labels:
          app: testserver
        name: testserver
        namespace: default
      spec:
        internalTrafficPolicy: Cluster
        ipFamilies:
          - IPv4
        ipFamilyPolicy: SingleStack
        ports:
          - name: http
            port: 8080
            protocol: TCP
            targetPort: 8080
          - name: metrics
            port: 15020
            protocol: TCP
            targetPort: 15020
        selector:
          app: testserver
        type: ClusterIP
                                      
    2. 执行以下命令,部署testserver的Service。
      kubectl apply -f testservice.yaml
  4. 部署gotest应用。
    1. 使用以下内容,创建gotest.yaml文件。

      展开查看详细内容

      apiVersion: apps/v1
      kind: Deployment
      metadata:
        labels:
          app: gotest
        name: gotest
        namespace: default
      spec:
        replicas: 0
        selector:
          matchLabels:
            app: gotest
        template:
          metadata:
            creationTimestamp: null
            labels:
              app: gotest
          spec:
            containers:
            - args:
              - -c
              - "200"
              - -n
              - "10000"
              - -u
              - testserver:8080
              command:
              - /root/go-stress-testing-linux
              image: xocoder/go-stress-testing-linux:v0.1
              imagePullPolicy: Always
              name: gotest
              resources:
                limits:
                  cpu: 500m
    2. 执行以下命令,部署gotest应用。
      kubectl apply -f gotest.yaml

步骤二:创建ASMAdaptiveConcurrency

  1. 通过kubectl连接ASM实例
  2. 使用以下内容,创建adaptiveconcurrency.yaml

    展开查看详细内容

    apiVersion: istio.alibabacloud.com/v1beta1
    kind: ASMAdaptiveConcurrency
    metadata:
        name: sample-adaptive-concurrency
        namespace: default
    spec:
        workload_selector:
            labels:
                app: testserver
        sample_aggregate_percentile:
            value: 60
        concurrency_limit_params:
            max_concurrency_limit: 500
            concurrency_update_interval: 15s
        min_rtt_calc_params:
            interval: 60s
            request_count: 100
            jitter:
                value: 15
            min_concurrency: 50
            buffer:
                value: 25
    参数 类型 描述 是否必填
    workload_selector WorkloadSelector 工作负载选择器,声明如何匹配生效的工作负载。
    labels map 列出需要匹配的工作负载(Pod)的Labels,用于匹配工作负载。
    sample_aggregate_percentile Percent 采样百分位,将采样请求的该百分位值作为SampleRTT参与计算。
    value int 百分比数,有效值为0~100。
    concurrency_limit_params ConcurrencyLimitParams 并发限制相关配置。
    max_concurrency_limit int 最大并发限制数。默认值1000。
    concurrency_update_interval duration 最大并发计算间隔,例如60s。
    min_rtt_calc_params MinRTTCalcParams 计算MinRTT的相关配置。
    interval duration 理想round-trip time计算间隔,例如120s。
    request_count int 统计多少请求的数据用作计算理想round-trip time。默认值为50。
    jitter Percent 计算理想round-trip time时,增加随机延迟的百分比,例如,interval为120s时,jitter为50,则间隔时间为ramdom(120, 120 + (120 * 50%))。默认值为15。
    min_concurrency int 计算理想round-trip time时的并发数量,同时也是控制器初始的并发数值。该值的取值应当远低于服务的瓶颈,从而使得服务在该并发下可以以最理想的延迟返回。默认值为3。
    buffer Percent 合理延迟波动范围(百分比),例如延迟在100ms上下时,10%浮动属于合理范围,则这个值设置为10。默认值为25。
  3. 执行以下命令,创建ASMAdaptiveConcurrency。
    kubectl apply -f adaptiveconcurrency.yaml

步骤三:启用ARMS Prometheus监控

为了对并发控制器的运行状态有直观的理解,以及便于对参数调优,您可以将自适应并发控制的相关Metrics输出到ARMS Prometheus,使用ARMS Prometheus监控查看并发控制器的运行状态。

  1. 启用ARMS Prometheus监控,具体操作,请参见ARMS Prometheus监控
  2. 在集群中配置ServiceMonitor,使得ARMS Prometheu可以获取到testserver数据。
    1. 使用以下内容,创建servicemonitor.yaml。

      展开查看详细内容

      apiVersion: monitoring.coreos.com/v1
      kind: ServiceMonitor
      metadata:
        name: testserver-envoy-metrics
        namespace: default
      spec:
        endpoints:
          - interval: 5s
            path: /stats/prometheus
            port: metrics
        namespaceSelector:
          any: true
        selector:
          matchLabels:
            app: testserver
    2. 执行以下命令,创建ServiceMonitor。
      kubectl apply -f servicemonitor.yaml

步骤四:验证ASMAdaptiveConcurrency的自适应并发控制是否成功

  1. 设置gotest的副本数为5。
    一个gotest应用副本将发起200个请求,5个副本则将发起1000个请求。
    1. 登录容器服务管理控制台
    2. 在控制台左侧导航栏中,单击集群
    3. 集群列表页面中,单击目标集群名称或者目标集群右侧操作列下的详情
    4. 在集群管理页左侧导航栏中,选择工作负载 > 无状态
    5. 无状态页面设置命名空间为default,在gotest应用右侧操作列下选择更多 > 查看YAML
    6. 编辑YAML对话框设置replicas5,单击更新
  2. 在应用实时监控服务ARMS导入Dashboard,查看并发控制器的运行状态。
    1. 登录容器服务管理控制台
    2. 在控制台左侧导航栏中,单击集群
    3. 集群列表页面中,单击目标集群名称或者目标集群右侧操作列下的详情
    4. 在集群管理页左侧导航栏中,选择运维管理 > Prometheus监控
    5. Prometheus监控页面右上角单击跳转到应用实时监控服务ARMS
    6. 大盘列表页面单击任意大盘的名称。
    7. 在左侧导航栏选择大盘 > Import
    8. Import via panel json文本框中输入以下内容,单击Load

      展开查看详细内容

      {
        "annotations": {
          "list": [
            {
              "builtIn": 1,
              "datasource": "-- Grafana --",
              "enable": true,
              "hide": true,
              "iconColor": "rgba(0, 211, 255, 1)",
              "name": "Annotations & Alerts",
              "type": "dashboard"
            }
          ]
        },
        "description": "monitoring ASM Adaptive Concurrency",
        "editable": true,
        "gnetId": 6693,
        "graphTooltip": 0,
        "id": 3239002,
        "iteration": 1651922323976,
        "links": [],
        "panels": [
          {
            "aliasColors": {},
            "bars": false,
            "dashLength": 10,
            "dashes": false,
            "datasource": "$cluster",
            "fieldConfig": {
              "defaults": {
                "custom": {}
              },
              "overrides": []
            },
            "fill": 1,
            "fillGradient": 0,
            "gridPos": {
              "h": 8,
              "w": 12,
              "x": 0,
              "y": 0
            },
            "hiddenSeries": false,
            "id": 22,
            "legend": {
              "avg": false,
              "current": false,
              "max": false,
              "min": false,
              "show": true,
              "total": false,
              "values": false
            },
            "lines": true,
            "linewidth": 1,
            "nullPointMode": "null",
            "options": {
              "alertThreshold": true
            },
            "percentage": false,
            "pluginVersion": "7.4.0-pre",
            "pointradius": 2,
            "points": false,
            "renderer": "flot",
            "seriesOverrides": [],
            "spaceLength": 10,
            "stack": false,
            "steppedLine": false,
            "targets": [
              {
                "expr": "envoy_http_inbound_0_0_0_0_8080_adaptive_concurrency_gradient_controller_rq_blocked{service=\"$service\", pod=\"$pod\"}",
                "interval": "",
                "legendFormat": "{{service}}-{{pod}}",
                "queryType": "randomWalk",
                "refId": "A"
              }
            ],
            "thresholds": [],
            "timeFrom": null,
            "timeRegions": [],
            "timeShift": null,
            "title": "RqBlocked",
            "tooltip": {
              "shared": true,
              "sort": 0,
              "value_type": "individual"
            },
            "type": "graph",
            "xaxis": {
              "buckets": null,
              "mode": "time",
              "name": null,
              "show": true,
              "values": []
            },
            "yaxes": [
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              },
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              }
            ],
            "yaxis": {
              "align": false,
              "alignLevel": null
            }
          },
          {
            "aliasColors": {},
            "bars": false,
            "dashLength": 10,
            "dashes": false,
            "datasource": "$cluster",
            "fieldConfig": {
              "defaults": {
                "custom": {}
              },
              "overrides": []
            },
            "fill": 1,
            "fillGradient": 0,
            "gridPos": {
              "h": 8,
              "w": 12,
              "x": 12,
              "y": 0
            },
            "hiddenSeries": false,
            "id": 24,
            "legend": {
              "avg": false,
              "current": false,
              "max": false,
              "min": false,
              "show": true,
              "total": false,
              "values": false
            },
            "lines": true,
            "linewidth": 1,
            "nullPointMode": "null",
            "options": {
              "alertThreshold": true
            },
            "percentage": false,
            "pluginVersion": "7.4.0-pre",
            "pointradius": 2,
            "points": false,
            "renderer": "flot",
            "seriesOverrides": [],
            "spaceLength": 10,
            "stack": false,
            "steppedLine": false,
            "targets": [
              {
                "expr": "envoy_http_inbound_0_0_0_0_8080_adaptive_concurrency_gradient_controller_burst_queue_size{service=\"$service\", pod=\"$pod\"}",
                "format": "time_series",
                "interval": "",
                "legendFormat": "{{service}}-{{pod}}",
                "queryType": "randomWalk",
                "refId": "A"
              }
            ],
            "thresholds": [],
            "timeFrom": null,
            "timeRegions": [],
            "timeShift": null,
            "title": "HeadRoom",
            "tooltip": {
              "shared": true,
              "sort": 0,
              "value_type": "individual"
            },
            "type": "graph",
            "xaxis": {
              "buckets": null,
              "mode": "time",
              "name": null,
              "show": true,
              "values": []
            },
            "yaxes": [
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              },
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              }
            ],
            "yaxis": {
              "align": false,
              "alignLevel": null
            }
          },
          {
            "aliasColors": {},
            "bars": false,
            "dashLength": 10,
            "dashes": false,
            "datasource": "$cluster",
            "fieldConfig": {
              "defaults": {
                "custom": {}
              },
              "overrides": []
            },
            "fill": 1,
            "fillGradient": 0,
            "gridPos": {
              "h": 8,
              "w": 12,
              "x": 0,
              "y": 8
            },
            "hiddenSeries": false,
            "id": 26,
            "legend": {
              "avg": false,
              "current": false,
              "max": false,
              "min": false,
              "show": true,
              "total": false,
              "values": false
            },
            "lines": true,
            "linewidth": 1,
            "nullPointMode": "null",
            "options": {
              "alertThreshold": true
            },
            "percentage": false,
            "pluginVersion": "7.4.0-pre",
            "pointradius": 2,
            "points": false,
            "renderer": "flot",
            "seriesOverrides": [],
            "spaceLength": 10,
            "stack": false,
            "steppedLine": false,
            "targets": [
              {
                "expr": "envoy_http_inbound_0_0_0_0_8080_adaptive_concurrency_gradient_controller_concurrency_limit{service=\"$service\",pod=\"$pod\"}",
                "interval": "",
                "legendFormat": "{{service}}-{{pod}}",
                "queryType": "randomWalk",
                "refId": "A"
              }
            ],
            "thresholds": [],
            "timeFrom": null,
            "timeRegions": [],
            "timeShift": null,
            "title": "ConcurrencyLimit",
            "tooltip": {
              "shared": true,
              "sort": 0,
              "value_type": "individual"
            },
            "type": "graph",
            "xaxis": {
              "buckets": null,
              "mode": "time",
              "name": null,
              "show": true,
              "values": []
            },
            "yaxes": [
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              },
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              }
            ],
            "yaxis": {
              "align": false,
              "alignLevel": null
            }
          },
          {
            "aliasColors": {},
            "bars": false,
            "dashLength": 10,
            "dashes": false,
            "datasource": "$cluster",
            "fieldConfig": {
              "defaults": {
                "custom": {}
              },
              "overrides": []
            },
            "fill": 1,
            "fillGradient": 0,
            "gridPos": {
              "h": 8,
              "w": 12,
              "x": 12,
              "y": 8
            },
            "hiddenSeries": false,
            "id": 28,
            "legend": {
              "avg": false,
              "current": false,
              "max": false,
              "min": false,
              "show": true,
              "total": false,
              "values": false
            },
            "lines": true,
            "linewidth": 1,
            "nullPointMode": "null",
            "options": {
              "alertThreshold": true
            },
            "percentage": false,
            "pluginVersion": "7.4.0-pre",
            "pointradius": 2,
            "points": false,
            "renderer": "flot",
            "seriesOverrides": [],
            "spaceLength": 10,
            "stack": false,
            "steppedLine": false,
            "targets": [
              {
                "expr": "envoy_http_inbound_0_0_0_0_8080_adaptive_concurrency_gradient_controller_gradient{service=\"$service\",pod=\"$pod\"}",
                "interval": "",
                "legendFormat": "{{service}}-{{pod}}",
                "queryType": "randomWalk",
                "refId": "A"
              }
            ],
            "thresholds": [],
            "timeFrom": null,
            "timeRegions": [],
            "timeShift": null,
            "title": "Gradient",
            "tooltip": {
              "shared": true,
              "sort": 0,
              "value_type": "individual"
            },
            "type": "graph",
            "xaxis": {
              "buckets": null,
              "mode": "time",
              "name": null,
              "show": true,
              "values": []
            },
            "yaxes": [
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              },
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              }
            ],
            "yaxis": {
              "align": false,
              "alignLevel": null
            }
          },
          {
            "aliasColors": {},
            "bars": false,
            "dashLength": 10,
            "dashes": false,
            "datasource": "$cluster",
            "fieldConfig": {
              "defaults": {
                "custom": {}
              },
              "overrides": []
            },
            "fill": 1,
            "fillGradient": 0,
            "gridPos": {
              "h": 8,
              "w": 12,
              "x": 0,
              "y": 16
            },
            "hiddenSeries": false,
            "id": 32,
            "legend": {
              "avg": false,
              "current": false,
              "max": false,
              "min": false,
              "show": true,
              "total": false,
              "values": false
            },
            "lines": true,
            "linewidth": 1,
            "nullPointMode": "null",
            "options": {
              "alertThreshold": true
            },
            "percentage": false,
            "pluginVersion": "7.4.0-pre",
            "pointradius": 2,
            "points": false,
            "renderer": "flot",
            "seriesOverrides": [],
            "spaceLength": 10,
            "stack": false,
            "steppedLine": false,
            "targets": [
              {
                "expr": "envoy_http_inbound_0_0_0_0_8080_adaptive_concurrency_gradient_controller_min_rtt_msecs{service=\"$service\",pod=\"$pod\"}",
                "interval": "",
                "legendFormat": "{{service}}-{{pod}}",
                "queryType": "randomWalk",
                "refId": "A"
              }
            ],
            "thresholds": [],
            "timeFrom": null,
            "timeRegions": [],
            "timeShift": null,
            "title": "MinRTT(msec)",
            "tooltip": {
              "shared": true,
              "sort": 0,
              "value_type": "individual"
            },
            "type": "graph",
            "xaxis": {
              "buckets": null,
              "mode": "time",
              "name": null,
              "show": true,
              "values": []
            },
            "yaxes": [
              {
                "format": "ms",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              },
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              }
            ],
            "yaxis": {
              "align": false,
              "alignLevel": null
            }
          },
          {
            "aliasColors": {},
            "bars": false,
            "dashLength": 10,
            "dashes": false,
            "datasource": "$cluster",
            "fieldConfig": {
              "defaults": {
                "custom": {}
              },
              "overrides": []
            },
            "fill": 1,
            "fillGradient": 0,
            "gridPos": {
              "h": 8,
              "w": 12,
              "x": 12,
              "y": 16
            },
            "hiddenSeries": false,
            "id": 34,
            "legend": {
              "avg": false,
              "current": false,
              "max": false,
              "min": false,
              "show": true,
              "total": false,
              "values": false
            },
            "lines": true,
            "linewidth": 1,
            "nullPointMode": "null",
            "options": {
              "alertThreshold": true
            },
            "percentage": false,
            "pluginVersion": "7.4.0-pre",
            "pointradius": 2,
            "points": false,
            "renderer": "flot",
            "seriesOverrides": [],
            "spaceLength": 10,
            "stack": false,
            "steppedLine": false,
            "targets": [
              {
                "expr": "envoy_http_inbound_0_0_0_0_8080_adaptive_concurrency_gradient_controller_sample_rtt_msecs{service=\"$service\",pod=\"$pod\"}",
                "interval": "",
                "legendFormat": "{{service}}-{{pod}}",
                "queryType": "randomWalk",
                "refId": "A"
              }
            ],
            "thresholds": [],
            "timeFrom": null,
            "timeRegions": [],
            "timeShift": null,
            "title": "SampleRTT(msec)",
            "tooltip": {
              "shared": true,
              "sort": 0,
              "value_type": "individual"
            },
            "type": "graph",
            "xaxis": {
              "buckets": null,
              "mode": "time",
              "name": null,
              "show": true,
              "values": []
            },
            "yaxes": [
              {
                "format": "ms",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              },
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              }
            ],
            "yaxis": {
              "align": false,
              "alignLevel": null
            }
          },
          {
            "aliasColors": {},
            "bars": false,
            "dashLength": 10,
            "dashes": false,
            "datasource": "test-adaptive-concurrency_1217520382582089",
            "fieldConfig": {
              "defaults": {
                "custom": {}
              },
              "overrides": []
            },
            "fill": 1,
            "fillGradient": 0,
            "gridPos": {
              "h": 8,
              "w": 12,
              "x": 0,
              "y": 24
            },
            "hiddenSeries": false,
            "id": 30,
            "legend": {
              "avg": false,
              "current": false,
              "max": false,
              "min": false,
              "show": true,
              "total": false,
              "values": false
            },
            "lines": true,
            "linewidth": 1,
            "nullPointMode": "null",
            "options": {
              "alertThreshold": true
            },
            "percentage": false,
            "pluginVersion": "7.4.0-pre",
            "pointradius": 2,
            "points": false,
            "renderer": "flot",
            "seriesOverrides": [],
            "spaceLength": 10,
            "stack": false,
            "steppedLine": false,
            "targets": [
              {
                "expr": "envoy_http_inbound_0_0_0_0_8080_adaptive_concurrency_gradient_controller_min_rtt_calculation_active{service=\"$service\",pod=\"$pod\"}",
                "interval": "",
                "legendFormat": "{{service}}-{{pod}}",
                "queryType": "randomWalk",
                "refId": "A"
              }
            ],
            "thresholds": [],
            "timeFrom": null,
            "timeRegions": [],
            "timeShift": null,
            "title": "MinRTTCalc",
            "tooltip": {
              "shared": true,
              "sort": 0,
              "value_type": "individual"
            },
            "type": "graph",
            "xaxis": {
              "buckets": null,
              "mode": "time",
              "name": null,
              "show": true,
              "values": []
            },
            "yaxes": [
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              },
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              }
            ],
            "yaxis": {
              "align": false,
              "alignLevel": null
            }
          }
        ],
        "refresh": "5s",
        "schemaVersion": 26,
        "style": "dark",
        "tags": [],
        "templating": {
          "list": [
            {
              "current": {
                "selected": true,
                "text": "edas120_1217520382582089",
                "value": "edas120_1217520382582089"
              },
              "error": null,
              "hide": 0,
              "includeAll": false,
              "label": null,
              "multi": false,
              "name": "cluster",
              "options": [],
              "query": "prometheus",
              "queryValue": "",
              "refresh": 1,
              "regex": "",
              "skipUrlSync": false,
              "type": "datasource"
            },
            {
              "allValue": null,
              "current": {
                "isNone": true,
                "selected": false,
                "text": "None",
                "value": ""
              },
              "datasource": "$cluster",
              "definition": "label_values(envoy_http_inbound_0_0_0_0_8080_adaptive_concurrency_gradient_controller_burst_queue_size,service)",
              "error": null,
              "hide": 0,
              "includeAll": false,
              "label": null,
              "multi": false,
              "name": "service",
              "options": [],
              "query": "label_values(envoy_http_inbound_0_0_0_0_8080_adaptive_concurrency_gradient_controller_burst_queue_size,service)",
              "refresh": 2,
              "regex": "",
              "skipUrlSync": false,
              "sort": 1,
              "tagValuesQuery": "",
              "tags": [],
              "tagsQuery": "",
              "type": "query",
              "useTags": false
            },
            {
              "allValue": null,
              "current": {
                "selected": false,
                "text": "All",
                "value": "$__all"
              },
              "datasource": "$cluster",
              "definition": "label_values(envoy_http_inbound_0_0_0_0_8080_adaptive_concurrency_gradient_controller_concurrency_limit, pod)",
              "error": null,
              "hide": 0,
              "includeAll": true,
              "label": null,
              "multi": true,
              "name": "pod",
              "options": [],
              "query": "label_values(envoy_http_inbound_0_0_0_0_8080_adaptive_concurrency_gradient_controller_concurrency_limit, pod)",
              "refresh": 2,
              "regex": "",
              "skipUrlSync": false,
              "sort": 0,
              "tagValuesQuery": "",
              "tags": [],
              "tagsQuery": "",
              "type": "query",
              "useTags": false
            }
          ]
        },
        "time": {
          "from": "now-15m",
          "to": "now"
        },
        "timepicker": {
          "refresh_intervals": [
            "5s",
            "10s",
            "30s",
            "1m",
            "5m",
            "15m",
            "30m",
            "1h",
            "2h",
            "1d"
          ],
          "time_options": [
            "5m",
            "15m",
            "1h",
            "6h",
            "12h",
            "24h",
            "2d",
            "7d",
            "30d"
          ]
        },
        "timezone": "",
        "title": "ASM Adaptive Concurrency",
        "uid": "000000084",
        "version": 3
      }
    9. Options页面单击Import
      说明 如果Options页面提示大盘UID冲突,您需要手动修改大盘UID,然后单击Import
    10. 在Dashboard中选择集群,设置Service为testserver,Pod为ALL。
      效果

      可以看到,gotest应用向testserver应用发起了1000个请求,但是testserver应用始终限制收到的并发数在500以内。说明使用ASMASMAdaptiveConcurrency的自适应并发控制成功。