Describe CloudWatch alarms for a metric using an AWS SDK - Amazon CloudWatch

Describe CloudWatch alarms for a metric using an AWS SDK

The following code examples show how to describe Amazon CloudWatch alarms for a metric.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples:

.NET
AWS SDK for .NET
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

/// <summary> /// Describe the current alarms for a specific metric. /// </summary> /// <param name="metricNamespace">The namespace of the metric.</param> /// <param name="metricName">The name of the metric.</param> /// <returns>The list of alarm data.</returns> public async Task<List<MetricAlarm>> DescribeAlarmsForMetric(string metricNamespace, string metricName) { var alarmsResult = await _amazonCloudWatch.DescribeAlarmsForMetricAsync( new DescribeAlarmsForMetricRequest() { Namespace = metricNamespace, MetricName = metricName }); return alarmsResult.MetricAlarms; }
C++
SDK for C++
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

Include the required files.

#include <aws/core/Aws.h> #include <aws/monitoring/CloudWatchClient.h> #include <aws/monitoring/model/DescribeAlarmsRequest.h> #include <aws/monitoring/model/DescribeAlarmsResult.h> #include <iomanip> #include <iostream>

Describe the alarms.

Aws::CloudWatch::CloudWatchClient cw; Aws::CloudWatch::Model::DescribeAlarmsRequest request; request.SetMaxRecords(1); bool done = false; bool header = false; while (!done) { auto outcome = cw.DescribeAlarms(request); if (!outcome.IsSuccess()) { std::cout << "Failed to describe CloudWatch alarms:" << outcome.GetError().GetMessage() << std::endl; break; } if (!header) { std::cout << std::left << std::setw(32) << "Name" << std::setw(64) << "Arn" << std::setw(64) << "Description" << std::setw(20) << "LastUpdated" << std::endl; header = true; } const auto &alarms = outcome.GetResult().GetMetricAlarms(); for (const auto &alarm : alarms) { std::cout << std::left << std::setw(32) << alarm.GetAlarmName() << std::setw(64) << alarm.GetAlarmArn() << std::setw(64) << alarm.GetAlarmDescription() << std::setw(20) << alarm.GetAlarmConfigurationUpdatedTimestamp().ToGmtString( SIMPLE_DATE_FORMAT_STR) << std::endl; } const auto &next_token = outcome.GetResult().GetNextToken(); request.SetNextToken(next_token); done = next_token.empty(); }
CLI
AWS CLI

To display information about alarms associated with a metric

The following example uses the describe-alarms-for-metric command to display information about any alarms associated with the Amazon EC2 CPUUtilization metric and the instance with the ID i-0c986c72.:

aws cloudwatch describe-alarms-for-metric --metric-name CPUUtilization --namespace AWS/EC2 --dimensions Name=InstanceId,Value=i-0c986c72

Output:

{ "MetricAlarms": [ { "EvaluationPeriods": 10, "AlarmArn": "arn:aws:cloudwatch:us-east-1:111122223333:alarm:myHighCpuAlarm2", "StateUpdatedTimestamp": "2013-10-30T03:03:51.479Z", "AlarmConfigurationUpdatedTimestamp": "2013-10-30T03:03:50.865Z", "ComparisonOperator": "GreaterThanOrEqualToThreshold", "AlarmActions": [ "arn:aws:sns:us-east-1:111122223333:NotifyMe" ], "Namespace": "AWS/EC2", "AlarmDescription": "CPU usage exceeds 70 percent", "StateReasonData": "{\"version\":\"1.0\",\"queryDate\":\"2013-10-30T03:03:51.479+0000\",\"startDate\":\"2013-10-30T02:08:00.000+0000\",\"statistic\":\"Average\",\"period\":300,\"recentDatapoints\":[40.698,39.612,42.432,39.796,38.816,42.28,42.854,40.088,40.760000000000005,41.316],\"threshold\":70.0}", "Period": 300, "StateValue": "OK", "Threshold": 70.0, "AlarmName": "myHighCpuAlarm2", "Dimensions": [ { "Name": "InstanceId", "Value": "i-0c986c72" } ], "Statistic": "Average", "StateReason": "Threshold Crossed: 10 datapoints were not greater than or equal to the threshold (70.0). The most recent datapoints: [40.760000000000005, 41.316].", "InsufficientDataActions": [], "OKActions": [], "ActionsEnabled": true, "MetricName": "CPUUtilization" }, { "EvaluationPeriods": 2, "AlarmArn": "arn:aws:cloudwatch:us-east-1:111122223333:alarm:myHighCpuAlarm", "StateUpdatedTimestamp": "2014-04-09T18:59:06.442Z", "AlarmConfigurationUpdatedTimestamp": "2014-04-09T22:26:05.958Z", "ComparisonOperator": "GreaterThanThreshold", "AlarmActions": [ "arn:aws:sns:us-east-1:111122223333:HighCPUAlarm" ], "Namespace": "AWS/EC2", "AlarmDescription": "CPU usage exceeds 70 percent", "StateReasonData": "{\"version\":\"1.0\",\"queryDate\":\"2014-04-09T18:59:06.419+0000\",\"startDate\":\"2014-04-09T18:44:00.000+0000\",\"statistic\":\"Average\",\"period\":300,\"recentDatapoints\":[38.958,40.292],\"threshold\":70.0}", "Period": 300, "StateValue": "OK", "Threshold": 70.0, "AlarmName": "myHighCpuAlarm", "Dimensions": [ { "Name": "InstanceId", "Value": "i-0c986c72" } ], "Statistic": "Average", "StateReason": "Threshold Crossed: 2 datapoints were not greater than the threshold (70.0). The most recent datapoints: [38.958, 40.292].", "InsufficientDataActions": [], "OKActions": [], "ActionsEnabled": false, "MetricName": "CPUUtilization" } ] }
Java
SDK for Java 2.x
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

public static void checkForMetricAlarm(CloudWatchClient cw, String fileName) { try { // Read values from the JSON file. JsonParser parser = new JsonFactory().createParser(new File(fileName)); com.fasterxml.jackson.databind.JsonNode rootNode = new ObjectMapper().readTree(parser); String customMetricNamespace = rootNode.findValue("customMetricNamespace").asText(); String customMetricName = rootNode.findValue("customMetricName").asText(); boolean hasAlarm = false; int retries = 10; DescribeAlarmsForMetricRequest metricRequest = DescribeAlarmsForMetricRequest.builder() .metricName(customMetricName) .namespace(customMetricNamespace) .build(); while (!hasAlarm && retries > 0) { DescribeAlarmsForMetricResponse response = cw.describeAlarmsForMetric(metricRequest); hasAlarm = response.hasMetricAlarms(); retries--; Thread.sleep(20000); System.out.println("."); } if (!hasAlarm) System.out.println("No Alarm state found for " + customMetricName + " after 10 retries."); else System.out.println("Alarm state found for " + customMetricName + "."); } catch (CloudWatchException | IOException | InterruptedException e) { System.err.println(e.getMessage()); System.exit(1); } }
JavaScript
SDK for JavaScript (v3)
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

Import the SDK and client modules and call the API.

import { DescribeAlarmsCommand } from "@aws-sdk/client-cloudwatch"; import { client } from "../libs/client.js"; const run = async () => { const command = new DescribeAlarmsCommand({ AlarmNames: [process.env.CLOUDWATCH_ALARM_NAME], // Set the value of CLOUDWATCH_ALARM_NAME to the name of an existing alarm. }); try { return await client.send(command); } catch (err) { console.error(err); } }; export default run();

Create the client in a separate module and export it.

import { CloudWatchClient } from "@aws-sdk/client-cloudwatch"; export const client = new CloudWatchClient({});
SDK for JavaScript (v2)
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

// Load the AWS SDK for Node.js var AWS = require("aws-sdk"); // Set the region AWS.config.update({ region: "REGION" }); // Create CloudWatch service object var cw = new AWS.CloudWatch({ apiVersion: "2010-08-01" }); cw.describeAlarms({ StateValue: "INSUFFICIENT_DATA" }, function (err, data) { if (err) { console.log("Error", err); } else { // List the names of all current alarms in the console data.MetricAlarms.forEach(function (item, index, array) { console.log(item.AlarmName); }); } });
Kotlin
SDK for Kotlin
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

suspend fun checkForMetricAlarm(fileName: String?) { // Read values from the JSON file. val parser = JsonFactory().createParser(File(fileName)) val rootNode = ObjectMapper().readTree<JsonNode>(parser) val customMetricNamespace = rootNode.findValue("customMetricNamespace").asText() val customMetricName = rootNode.findValue("customMetricName").asText() var hasAlarm = false var retries = 10 val metricRequest = DescribeAlarmsForMetricRequest { metricName = customMetricName namespace = customMetricNamespace } CloudWatchClient { region = "us-east-1" }.use { cwClient -> while (!hasAlarm && retries > 0) { val response = cwClient.describeAlarmsForMetric(metricRequest) if (response.metricAlarms?.count()!! > 0) { hasAlarm = true } retries-- delay(20000) println(".") } if (!hasAlarm) println("No Alarm state found for $customMetricName after 10 retries.") else println("Alarm state found for $customMetricName.") } }
Python
SDK for Python (Boto3)
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

class CloudWatchWrapper: """Encapsulates Amazon CloudWatch functions.""" def __init__(self, cloudwatch_resource): """ :param cloudwatch_resource: A Boto3 CloudWatch resource. """ self.cloudwatch_resource = cloudwatch_resource def get_metric_alarms(self, metric_namespace, metric_name): """ Gets the alarms that are currently watching the specified metric. :param metric_namespace: The namespace of the metric. :param metric_name: The name of the metric. :returns: An iterator that yields the alarms. """ metric = self.cloudwatch_resource.Metric(metric_namespace, metric_name) alarm_iter = metric.alarms.all() logger.info("Got alarms for metric %s.%s.", metric_namespace, metric_name) return alarm_iter
Ruby
SDK for Ruby
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

# # @param cloudwatch_client [Aws::CloudWatch::Client] # An initialized CloudWatch client. # @example # describe_metric_alarms(Aws::CloudWatch::Client.new(region: 'us-east-1')) def describe_metric_alarms(cloudwatch_client) response = cloudwatch_client.describe_alarms if response.metric_alarms.count.positive? response.metric_alarms.each do |alarm| puts "-" * 16 puts "Name: " + alarm.alarm_name puts "State value: " + alarm.state_value puts "State reason: " + alarm.state_reason puts "Metric: " + alarm.metric_name puts "Namespace: " + alarm.namespace puts "Statistic: " + alarm.statistic puts "Period: " + alarm.period.to_s puts "Unit: " + alarm.unit.to_s puts "Eval. periods: " + alarm.evaluation_periods.to_s puts "Threshold: " + alarm.threshold.to_s puts "Comp. operator: " + alarm.comparison_operator if alarm.key?(:ok_actions) && alarm.ok_actions.count.positive? puts "OK actions:" alarm.ok_actions.each do |a| puts " " + a end end if alarm.key?(:alarm_actions) && alarm.alarm_actions.count.positive? puts "Alarm actions:" alarm.alarm_actions.each do |a| puts " " + a end end if alarm.key?(:insufficient_data_actions) && alarm.insufficient_data_actions.count.positive? puts "Insufficient data actions:" alarm.insufficient_data_actions.each do |a| puts " " + a end end puts "Dimensions:" if alarm.key?(:dimensions) && alarm.dimensions.count.positive? alarm.dimensions.each do |d| puts " Name: " + d.name + ", Value: " + d.value end else puts " None for this alarm." end end else puts "No alarms found." end rescue StandardError => e puts "Error getting information about alarms: #{e.message}" end # Example usage: def run_me region = "" # Print usage information and then stop. if ARGV[0] == "--help" || ARGV[0] == "-h" puts "Usage: ruby cw-ruby-example-show-alarms.rb REGION" puts "Example: ruby cw-ruby-example-show-alarms.rb us-east-1" exit 1 # If no values are specified at the command prompt, use these default values. elsif ARGV.count.zero? region = "us-east-1" # Otherwise, use the values as specified at the command prompt. else region = ARGV[0] end cloudwatch_client = Aws::CloudWatch::Client.new(region: region) puts "Available alarms:" describe_metric_alarms(cloudwatch_client) end run_me if $PROGRAM_NAME == __FILE__

For a complete list of AWS SDK developer guides and code examples, see Using CloudWatch with an AWS SDK. This topic also includes information about getting started and details about previous SDK versions.