在aws elasticache redis-cluster中，我们如何查看哪些节点是主节点或副本节点？

Question

点击下面的链接：

http://docs.aws.amazon.com/AmazonElastiCache/latest/UserGuide/ClientConfig.ReplicationGroup.html

目前存在以下内容：

REPLICATIONGROUP  my-repgroup  My replication group  available

  CLUSTERID  my-redis-primary
  CLUSTERID  my-replica-1
  NODEGROUP  0001  my-repgroup.f310xz.ng.0001.cache.amazonaws.com  6379  available
        NODEGROUPMEMBER  my-redis-primary    0001  my-redis-primary.f310xz.0001.cache.amazonaws.com   6379  us-west-2a  primary
        NODEGROUPMEMBER  my-replica-1        0001  my-replica-1.f310xz.0001.cache.amazonaws.com       6379  us-west-2b  replica
Connecting to Clusters in a Replication Group (ElastiCache API)

在上图中，最右边

有‘主’和‘副本’

从今天起，在aws控制台中，

当我发出“describe-replication-groups”命令

我看不到‘主’和‘副本’

相反，我看到的内容如下所示：

"NodeGroupMembers": [
    {
        "PreferredAvailabilityZone": "us-west-2b", 
        "CacheNodeId": "0001", 
        "CacheClusterId": "ec-redis-cluster1-0001-001"
    }, 
    {
        "PreferredAvailabilityZone": "us-west-2b", 
        "CacheNodeId": "0001", 
        "CacheClusterId": "ec-redis-cluster1-0001-002"
    }, 
    {
        "PreferredAvailabilityZone": "us-west-2b", 
        "CacheNodeId": "0001", 
        "CacheClusterId": "ec-redis-cluster1-0001-003"
    }
]

我试过各种命令，都没找到。

我可以通过什么方式查看某些碎片/节点是否是主/复制副本的详细信息

提前感谢

Answer 1

echo "cluster nodes" | redis-cli -c -h redis-cluster | grep master

Answer 2

AWS Elasticache Redis设置创建为多节点设置时有两种模式-群集模式启用和禁用，如here所述。这对手头的问题很重要。

如果您的ElastiCache群集中处于群集模式，则禁用，然后执行

aws describe-elasticache-replication-groups --replication-group-id test-1 

将显示类似以下内容的输出：

{
  "CurrentRole": "replica",
    "PreferredAvailabilityZone": "us-west-1c",
    "CacheNodeId": "0001",
    "ReadEndpoint": {
      "Port": 6379,
      "Address": "xxxx"
    },
    "CacheClusterId": "xxxx"
},
{
  "CurrentRole": "primary",
  "PreferredAvailabilityZone": "us-west-1c",
  "CacheNodeId": "0001",
  "ReadEndpoint": {
    "Port": 6379,
    "Address": "xxxx"
  },
  "CacheClusterId": "xxxx"
}

这将帮助您确定目标节点的主角色或副本角色。密钥CurrentRole在AWS Elasticache群集模式enabled中不可用

aws describe-elasticache-replication-groups --replication-group-id test-2 

将显示类似于以下内容的输出：

{
    "PreferredAvailabilityZone": "us-west-1c",
        "CacheNodeId": "0001",
        "CacheClusterId": "xxxxx"
},
{
    "PreferredAvailabilityZone": "us-west-1c",
    "CacheNodeId": "0001",
    "CacheClusterId": "xxxxxxx"
},

上面的输出没有、CurrentRole、或任何其他相应的键来深入了解节点的角色。在这种情况下，您有两个选择：

1. 如果你有权访问AWS Elasticache Redis集群的端口6379 -通过遵循Abhishek之前的回答来获取主/从信息。
2. 如果你没有对集群的访问权限，即如果你正在编写一个AWS Lambda或一些不在无法访问集群端口6379的机器上运行的代码，那么间接的方法是检查每个分片的每个节点的IsMaster指标：

aws cloudwatch get-metric-data --cli-input-json file://test.json

其中test.json看起来像这样：

{
  "MetricDataQueries": [
    {
      "Id": "is_master_test",
      "MetricStat": {
        "Metric": {
          "Namespace": "AWS/ElastiCache",
          "MetricName": "IsMaster",
          "Dimensions": [
            {
              "Name": "CacheClusterId",
              "Value": "xxxxx"
            },
             {
              "Name": "CacheNodeId",
              "Value": "0001"
            }
          ]
        },
        "Period": 60,
        "Stat": "Minimum",
        "Unit": "Count"
      },
      "Label": "is_master_test",
      "ReturnData": true
    }
  ],
  "StartTime": "2019-06-12T10:08:0000",
  "EndTime": "2019-06-12T10:09:0000"
}

如果目标节点是主节点，则输出将如下所示：

{
    "MetricDataResults": [
        {
            "Timestamps": [
              "2019-06-12T10:05:00Z"
            ],
            "StatusCode": "Complete",
            "Values": [
              1.0
            ],
            "Id": "is_master_test",
            "Label": "is_master_test"
        }
    ]
}

如果目标节点不是主节点，则输出将如下所示：

{
    "MetricDataResults": [
        {
            "Timestamps": [
                "2019-06-12T10:05:00Z"
            ],
            "StatusCode": "Complete",
            "Values": [
                0.0
            ],
            "Id": "is_master_test",
            "Label": "is_master_test"
        }
    ]
}

请注意，我使用指标"Minimum“来检查此节点是否至少在最后1分钟内作为Master。