AttributeError：“ResultSet”对象没有属性“create_alarm”

Question

我想用 cloudwatch 监控一个名为“topic”的主题。

使用 cloudwatch，我希望当这个主题“主题”的 NumberOfMessagesPublished > 100 时，我想向其他名为“cloudwatchSNS”的主题发送通知。

我尝试使用以下代码执行此操作，但出现此错误：

AttributeError: 'ResultSet' object has no attribute 'create_alarm'

你能帮我把它正常工作吗？

import boto.sns
from boto.ec2.cloudwatch import MetricAlarm
import boto.ec2.cloudwatch

sns = boto.sns.connect_to_region("us-east-1")
cloudwatch = boto.ec2.cloudwatch.connect_to_region("us-east-1")

#topic to send notification when NumberOfMessagesPublished > 100
topicToSendNotification = sns.create_topic("cloudwatchSNS")

topicArnToSendNotification = topicarn['CreateTopicResponse']['CreateTopicResult']['TopicArn']

#topicName to control the number of messages published
topicNameToMonitor = "topic"

#subscriptor in topic to receive an email when NumberOfMessagesPublished > 100
subscription = sns.subscribe(topicArnToSendNotification, "email", "mail@mail.com")

metric = cloudwatch.list_metrics(dimensions={'TopicName':topicNameToMonitor},
                         metric_name="NumberOfMessagesPublished")

alarmName = "test"

metric.create_alarm(name=alarmName, comparison='>=', threshold=100, period=300,
                    evaluation_periods=2, statistic='Average', alarm_actions=[topicarnToSendNotification])

Answer 1

调用cloud watch.list_metrics(...) 将始终返回一个名为ResultSet 的类似列表的对象，即使只有1 个结果。在尝试对其创建警报之前，您需要从列表中取出实际的 Metric 对象。

metric = cloudwatch.list_metrics(dimensions={'TopicName':topicNameToMonitor},
                     metric_name="NumberOfMessagesPublished")[0]