AWS Auto Scaling Group 未从 ELB 检测到实例不健康

Question

我正在尝试让 AWS Auto Scaling Group 替换“不健康”的实例，但我无法让它工作。

我从控制台创建了一个启动配置，并从那里创建了一个带有 Application Load Balancer 的 Auto Scaling 组。我将有关目标组和听众的所有设置都保留为默认设置。我选择“ELB”作为 Auto Scaling 组的附加健康检查类型。我故意错误配置了启动配置，导致实例“损坏”——没有网络服务器来监听监听器中配置的端口。

Auto Scaling 组似乎配置正确并且肯定知道负载均衡器。然而，它认为它启动的实例是健康的。

// output of aws autoscaling describe-auto-scaling-groups:

{
    "AutoScalingGroups": [
        {
            "AutoScalingGroupName": "MyAutoScalingGroup",
            "AutoScalingGroupARN": "arn:aws:autoscaling:eu-west-1:<accountId>:autoScalingGroup:3edc728f-0831-46b9-bbcc-16691adc8f44:autoScalingGroupName/MyAutoScalingGroup",
            "LaunchConfigurationName": "MyLaunchConfiguration",
            "MinSize": 1,
            "MaxSize": 3,
            "DesiredCapacity": 1,
            "DefaultCooldown": 300,
            "AvailabilityZones": [
                "eu-west-1b",
                "eu-west-1c",
                "eu-west-1a"
            ],
            "LoadBalancerNames": [],
            "TargetGroupARNs": [
                "arn:aws:elasticloadbalancing:eu-west-1:<accountId>:targetgroup/MyAutoScalingGroup-1/1e36c863abaeb6ff"
            ],
            "HealthCheckType": "ELB",
            "HealthCheckGracePeriod": 300,
            "Instances": [
                {
                    "InstanceId": "i-0b589d33100e4e515",
                    // ...
                    "LifecycleState": "InService",
                    "HealthStatus": "Healthy",
                    // ...
                }
            ],
            // ...
        }
    ]
}

但是，负载均衡器非常清楚该实例 不健康:

// output of aws elbv2 describe-target-health:

{
    "TargetHealthDescriptions": [
        {
            "Target": {
                "Id": "i-0b589d33100e4e515",
                "Port": 80
            },
            "HealthCheckPort": "80",
            "TargetHealth": {
                "State": "unhealthy",
                "Reason": "Target.Timeout",
                "Description": "Request timed out"
            }
        }
    ]
}

我是不是误解了documentation？如果不是，还需要做些什么才能让 Auto Scaling Group 了解此实例不健康并刷新它？

需要说明的是，当手动将实例标记为不健康时（即使用 aws autoscaling set-instance-health），它们会按预期进行刷新。

Answer 1

说明

如果您从一开始就故意错误配置了实例，并且 ELB 健康检查从未通过，那么 Auto Scaling 组尚未确认您的 ELB/Target 组已启动并且运行。请参阅文档的此 page。

After at least one registered instance passes the health checks, it enters the InService state.

和

If no registered instances pass the health checks (for example, due to a misconfigured health check), ... Amazon EC2 Auto Scaling doesn't terminate and replace the instances.

我从头开始配置并达到了与您描述的相同的行为。要验证这确实是根本原因，请检查 ASG 中的目标组状态。它可能处于 Added 状态而不是 InService.

[cloudshell-user@ip-10-0-xx-xx ~]$ aws autoscaling describe-load-balancer-target-groups --auto-scaling-group-name test-asg
{
    "LoadBalancerTargetGroups": [
        {
            "LoadBalancerTargetGroupARN": "arn:aws:elasticloadbalancing:us-east-1:xxx:targetgroup/asg-test-1/abc",
            "State": "Added"
        }

分辨率

为了达到预期的效果，我所做的是

运行端口 80 上的简单 Web 服务。确保安全组已打开，以便 ELB 与 EC2 通信。
等到 ELB 状态正常。确保服务器返回 200。您可能需要创建一个空的 index.html 才能通过健康检查。
等到目标组在 ASG 中的状态变为 InService。

例如，对于第 3 步：

[cloudshell-user@ip-10-0-xx-xx ~]$ aws autoscaling describe-load-balancer-target-groups --auto-scaling-group-name test-asg
{
    "LoadBalancerTargetGroups": [
        {
            "LoadBalancerTargetGroupARN": "arn:aws:elasticloadbalancing:us-east-1:xxx:targetgroup/test-asg-1-alb/abcdef",
            "State": "InService"
        }
    ]
}

既然已经投入使用，请关闭网络服务器并等待。不过，请经常检查，因为一旦 ASG 检测到它不健康，它就会终止。

[cloudshell-user@ip-10-0-xx-xx ~]$ aws autoscaling describe-auto-scaling-groups
{
    "AutoScalingGroups": [
        {
            "AutoScalingGroupName": "test-asg",
            "AutoScalingGroupARN": "arn:aws:autoscaling:us-east-1:xxx:autoScalingGroup:abc-def-ghi:autoScalingGroupName/test-asg",
            ...
            "LoadBalancerNames": [],
            "TargetGroupARNs": [
                "arn:aws:elasticloadbalancing:us-east-1:xxx:targetgroup/test-asg-1-alb/abc"
            ],
            "HealthCheckType": "ELB",
            "HealthCheckGracePeriod": 300,
            "Instances": [
                {
                    "InstanceId": "i-04bed6ef3b2000326",
                    "InstanceType": "t2.micro",
                    "AvailabilityZone": "us-east-1b",
                    "LifecycleState": "Terminating",
                    "HealthStatus": "Unhealthy",
                    "LaunchTemplate": {
                        "LaunchTemplateId": "lt-0452c90319362cbc5",
                        "LaunchTemplateName": "test-template",
                        "Version": "1"
                    },
             ...
        },
    ...
    ]
}

AWS Auto Scaling Group 未从 ELB 检测到实例不健康

AWS Auto Scaling Group does not detect instance is unhealthy from ELB

amazon-web-services

aws-application-load-balancer

aws-auto-scaling

说明

分辨率