文档 AWS SDK 示例 GitHub 存储库中还有更多 [S AWS DK 示例](https://github.com/awsdocs/aws-doc-sdk-examples)。

本文属于机器翻译版本。若本译文内容与英语原文存在差异，则一律以英文原文为准。

# CloudWatch 使用场景 AWS SDKs
<a name="cloudwatch_code_examples_scenarios"></a>

以下代码示例向您展示了如何在中 CloudWatch实现常见场景 AWS SDKs。这些场景向您展示了如何通过在其中调用多个函数 CloudWatch 或与其他函数组合来完成特定任务 AWS 服务。每个场景都包含完整源代码的链接，您可以在其中找到有关如何设置和运行代码的说明。

场景以中等水平的经验为目标，可帮助您结合具体环境了解服务操作。

**Topics**
+ [开始使用警报](cloudwatch_example_cloudwatch_Scenario_GettingStarted_section.md)
+ [管理指标和告警](cloudwatch_example_cloudwatch_Usage_MetricsAlarms_section.md)
+ [监控 DynamoDB 性能](cloudwatch_example_cross_MonitorDynamoDB_section.md)

# 使用 AWS SDK 开始使用 CloudWatch 警报
<a name="cloudwatch_example_cloudwatch_Scenario_GettingStarted_section"></a>

以下代码示例展示了如何：
+ 创建警报。
+ 禁用警报操作。
+ 描述警报。
+ 删除警报。

------
#### [ SAP ABAP ]

**适用于 SAP ABAP 的 SDK**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/cwt#code-examples)中查找完整示例，了解如何进行设置和运行。

```
    DATA lt_alarmnames TYPE /aws1/cl_cwtalarmnames_w=>tt_alarmnames.
    DATA lo_alarmname TYPE REF TO /aws1/cl_cwtalarmnames_w.

    "Create an alarm"
    TRY.
        lo_cwt->putmetricalarm(
          iv_alarmname                 = iv_alarm_name
          iv_comparisonoperator        = iv_comparison_operator
          iv_evaluationperiods         = iv_evaluation_periods
          iv_metricname                = iv_metric_name
          iv_namespace                 = iv_namespace
          iv_statistic                 = iv_statistic
          iv_threshold                 = iv_threshold
          iv_actionsenabled            = iv_actions_enabled
          iv_alarmdescription          = iv_alarm_description
          iv_unit                      = iv_unit
          iv_period                    = iv_period
          it_dimensions                = it_dimensions ).
        MESSAGE 'Alarm created' TYPE 'I'.
      CATCH /aws1/cx_cwtlimitexceededfault.
        MESSAGE 'The request processing has exceeded the limit' TYPE 'E'.
    ENDTRY.

    "Create an ABAP internal table for the created alarm."
    lo_alarmname = NEW #( iv_value = iv_alarm_name ).
    INSERT lo_alarmname INTO TABLE lt_alarmnames.

    "Disable alarm actions."
    TRY.
        lo_cwt->disablealarmactions(
          it_alarmnames                = lt_alarmnames ).
        MESSAGE 'Alarm actions disabled' TYPE 'I'.
      CATCH /aws1/cx_rt_service_generic INTO DATA(lo_disablealarm_exception).
        DATA(lv_disablealarm_error) = |"{ lo_disablealarm_exception->av_err_code }" - { lo_disablealarm_exception->av_err_msg }|.
        MESSAGE lv_disablealarm_error TYPE 'E'.
    ENDTRY.

    "Describe alarm using the same ABAP internal table."
    TRY.
        oo_result = lo_cwt->describealarms(                       " oo_result is returned for testing purpose "
          it_alarmnames                = lt_alarmnames ).
        MESSAGE 'Alarms retrieved' TYPE 'I'.
      CATCH /aws1/cx_rt_service_generic INTO DATA(lo_describealarms_exception).
        DATA(lv_describealarms_error) = |"{ lo_describealarms_exception->av_err_code }" - { lo_describealarms_exception->av_err_msg }|.
        MESSAGE lv_describealarms_error TYPE 'E'.
    ENDTRY.

    "Delete alarm."
    TRY.
        lo_cwt->deletealarms(
          it_alarmnames = lt_alarmnames ).
        MESSAGE 'Alarms deleted' TYPE 'I'.
      CATCH /aws1/cx_cwtresourcenotfound.
        MESSAGE 'Resource being access is not found.' TYPE 'E'.
    ENDTRY.
```
+ 有关 API 详细信息，请参阅《AWS SDK for SAP ABAP API Reference》**中的以下主题。
  + [DeleteAlarms](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
  + [DescribeAlarms](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
  + [DisableAlarmActions](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
  + [PutMetricAlarm](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)

------

# 使用 AWS SDK 管理 CloudWatch 指标和警报
<a name="cloudwatch_example_cloudwatch_Usage_MetricsAlarms_section"></a>

以下代码示例展示了如何：
+ 创建警报以监视 CloudWatch 指标。
+ 将数据放入指标并触发告警。
+ 从告警中获取数据。
+ 删除告警。

------
#### [ Python ]

**适用于 Python 的 SDK（Boto3）**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/cloudwatch#code-examples)中查找完整示例，了解如何进行设置和运行。
创建一个封装 CloudWatch 操作的类。  

```
from datetime import datetime, timedelta
import logging
from pprint import pprint
import random
import time
import boto3
from botocore.exceptions import ClientError

logger = logging.getLogger(__name__)


class CloudWatchWrapper:
    """Encapsulates Amazon CloudWatch functions."""

    def __init__(self, cloudwatch_resource):
        """
        :param cloudwatch_resource: A Boto3 CloudWatch resource.
        """
        self.cloudwatch_resource = cloudwatch_resource


    def put_metric_data_set(self, namespace, name, timestamp, unit, data_set):
        """
        Sends a set of data to CloudWatch for a metric. All of the data in the set
        have the same timestamp and unit.

        :param namespace: The namespace of the metric.
        :param name: The name of the metric.
        :param timestamp: The UTC timestamp for the metric.
        :param unit: The unit of the metric.
        :param data_set: The set of data to send. This set is a dictionary that
                         contains a list of values and a list of corresponding counts.
                         The value and count lists must be the same length.
        """
        try:
            metric = self.cloudwatch_resource.Metric(namespace, name)
            metric.put_data(
                Namespace=namespace,
                MetricData=[
                    {
                        "MetricName": name,
                        "Timestamp": timestamp,
                        "Values": data_set["values"],
                        "Counts": data_set["counts"],
                        "Unit": unit,
                    }
                ],
            )
            logger.info("Put data set for metric %s.%s.", namespace, name)
        except ClientError:
            logger.exception("Couldn't put data set for metric %s.%s.", namespace, name)
            raise


    def create_metric_alarm(
        self,
        metric_namespace,
        metric_name,
        alarm_name,
        stat_type,
        period,
        eval_periods,
        threshold,
        comparison_op,
    ):
        """
        Creates an alarm that watches a metric.

        :param metric_namespace: The namespace of the metric.
        :param metric_name: The name of the metric.
        :param alarm_name: The name of the alarm.
        :param stat_type: The type of statistic the alarm watches.
        :param period: The period in which metric data are grouped to calculate
                       statistics.
        :param eval_periods: The number of periods that the metric must be over the
                             alarm threshold before the alarm is set into an alarmed
                             state.
        :param threshold: The threshold value to compare against the metric statistic.
        :param comparison_op: The comparison operation used to compare the threshold
                              against the metric.
        :return: The newly created alarm.
        """
        try:
            metric = self.cloudwatch_resource.Metric(metric_namespace, metric_name)
            alarm = metric.put_alarm(
                AlarmName=alarm_name,
                Statistic=stat_type,
                Period=period,
                EvaluationPeriods=eval_periods,
                Threshold=threshold,
                ComparisonOperator=comparison_op,
            )
            logger.info(
                "Added alarm %s to track metric %s.%s.",
                alarm_name,
                metric_namespace,
                metric_name,
            )
        except ClientError:
            logger.exception(
                "Couldn't add alarm %s to metric %s.%s",
                alarm_name,
                metric_namespace,
                metric_name,
            )
            raise
        else:
            return alarm


    def put_metric_data(self, namespace, name, value, unit):
        """
        Sends a single data value to CloudWatch for a metric. This metric is given
        a timestamp of the current UTC time.

        :param namespace: The namespace of the metric.
        :param name: The name of the metric.
        :param value: The value of the metric.
        :param unit: The unit of the metric.
        """
        try:
            metric = self.cloudwatch_resource.Metric(namespace, name)
            metric.put_data(
                Namespace=namespace,
                MetricData=[{"MetricName": name, "Value": value, "Unit": unit}],
            )
            logger.info("Put data for metric %s.%s", namespace, name)
        except ClientError:
            logger.exception("Couldn't put data for metric %s.%s", namespace, name)
            raise


    def get_metric_statistics(self, namespace, name, start, end, period, stat_types):
        """
        Gets statistics for a metric within a specified time span. Metrics are grouped
        into the specified period.

        :param namespace: The namespace of the metric.
        :param name: The name of the metric.
        :param start: The UTC start time of the time span to retrieve.
        :param end: The UTC end time of the time span to retrieve.
        :param period: The period, in seconds, in which to group metrics. The period
                       must match the granularity of the metric, which depends on
                       the metric's age. For example, metrics that are older than
                       three hours have a one-minute granularity, so the period must
                       be at least 60 and must be a multiple of 60.
        :param stat_types: The type of statistics to retrieve, such as average value
                           or maximum value.
        :return: The retrieved statistics for the metric.
        """
        try:
            metric = self.cloudwatch_resource.Metric(namespace, name)
            stats = metric.get_statistics(
                StartTime=start, EndTime=end, Period=period, Statistics=stat_types
            )
            logger.info(
                "Got %s statistics for %s.", len(stats["Datapoints"]), stats["Label"]
            )
        except ClientError:
            logger.exception("Couldn't get statistics for %s.%s.", namespace, name)
            raise
        else:
            return stats


    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


    def delete_metric_alarms(self, metric_namespace, metric_name):
        """
        Deletes all of 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.
        """
        try:
            metric = self.cloudwatch_resource.Metric(metric_namespace, metric_name)
            metric.alarms.delete()
            logger.info(
                "Deleted alarms for metric %s.%s.", metric_namespace, metric_name
            )
        except ClientError:
            logger.exception(
                "Couldn't delete alarms for metric %s.%s.",
                metric_namespace,
                metric_name,
            )
            raise
```
使用包装类将数据放入指标中，触发监控指标的告警，然后从告警中获取数据。  

```
def usage_demo():
    print("-" * 88)
    print("Welcome to the Amazon CloudWatch metrics and alarms demo!")
    print("-" * 88)

    logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")

    cw_wrapper = CloudWatchWrapper(boto3.resource("cloudwatch"))

    minutes = 20
    metric_namespace = "doc-example-metric"
    metric_name = "page_views"
    start = datetime.utcnow() - timedelta(minutes=minutes)
    print(
        f"Putting data into metric {metric_namespace}.{metric_name} spanning the "
        f"last {minutes} minutes."
    )
    for offset in range(0, minutes):
        stamp = start + timedelta(minutes=offset)
        cw_wrapper.put_metric_data_set(
            metric_namespace,
            metric_name,
            stamp,
            "Count",
            {
                "values": [
                    random.randint(bound, bound * 2)
                    for bound in range(offset + 1, offset + 11)
                ],
                "counts": [random.randint(1, offset + 1) for _ in range(10)],
            },
        )

    alarm_name = "high_page_views"
    period = 60
    eval_periods = 2
    print(f"Creating alarm {alarm_name} for metric {metric_name}.")
    alarm = cw_wrapper.create_metric_alarm(
        metric_namespace,
        metric_name,
        alarm_name,
        "Maximum",
        period,
        eval_periods,
        100,
        "GreaterThanThreshold",
    )
    print(f"Alarm ARN is {alarm.alarm_arn}.")
    print(f"Current alarm state is: {alarm.state_value}.")

    print(
        f"Sending data to trigger the alarm. This requires data over the threshold "
        f"for {eval_periods} periods of {period} seconds each."
    )
    while alarm.state_value == "INSUFFICIENT_DATA":
        print("Sending data for the metric.")
        cw_wrapper.put_metric_data(
            metric_namespace, metric_name, random.randint(100, 200), "Count"
        )
        alarm.load()
        print(f"Current alarm state is: {alarm.state_value}.")
        if alarm.state_value == "INSUFFICIENT_DATA":
            print(f"Waiting for {period} seconds...")
            time.sleep(period)
        else:
            print("Wait for a minute for eventual consistency of metric data.")
            time.sleep(period)
            if alarm.state_value == "OK":
                alarm.load()
                print(f"Current alarm state is: {alarm.state_value}.")

    print(
        f"Getting data for metric {metric_namespace}.{metric_name} during timespan "
        f"of {start} to {datetime.utcnow()} (times are UTC)."
    )
    stats = cw_wrapper.get_metric_statistics(
        metric_namespace,
        metric_name,
        start,
        datetime.utcnow(),
        60,
        ["Average", "Minimum", "Maximum"],
    )
    print(
        f"Got {len(stats['Datapoints'])} data points for metric "
        f"{metric_namespace}.{metric_name}."
    )
    pprint(sorted(stats["Datapoints"], key=lambda x: x["Timestamp"]))

    print(f"Getting alarms for metric {metric_name}.")
    alarms = cw_wrapper.get_metric_alarms(metric_namespace, metric_name)
    for alarm in alarms:
        print(f"Alarm {alarm.name} is currently in state {alarm.state_value}.")

    print(f"Deleting alarms for metric {metric_name}.")
    cw_wrapper.delete_metric_alarms(metric_namespace, metric_name)

    print("Thanks for watching!")
    print("-" * 88)
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的以下主题。
  + [DeleteAlarms](https://docs.aws.amazon.com/goto/boto3/monitoring-2010-08-01/DeleteAlarms)
  + [DescribeAlarmsForMetric](https://docs.aws.amazon.com/goto/boto3/monitoring-2010-08-01/DescribeAlarmsForMetric)
  + [DisableAlarmActions](https://docs.aws.amazon.com/goto/boto3/monitoring-2010-08-01/DisableAlarmActions)
  + [EnableAlarmActions](https://docs.aws.amazon.com/goto/boto3/monitoring-2010-08-01/EnableAlarmActions)
  + [GetMetricStatistics](https://docs.aws.amazon.com/goto/boto3/monitoring-2010-08-01/GetMetricStatistics)
  + [ListMetrics](https://docs.aws.amazon.com/goto/boto3/monitoring-2010-08-01/ListMetrics)
  + [PutMetricAlarm](https://docs.aws.amazon.com/goto/boto3/monitoring-2010-08-01/PutMetricAlarm)
  + [PutMetricData](https://docs.aws.amazon.com/goto/boto3/monitoring-2010-08-01/PutMetricData)

------

# 使用软件开发工具包监控亚马逊 DynamoDB 的性能 AWS
<a name="cloudwatch_example_cross_MonitorDynamoDB_section"></a>

以下代码示例显示如何配置应用程序使用 DynamoDB 来监控性能。

------
#### [ Java ]

**适用于 Java 的 SDK 2.x**  
 此示例说明如何配置 Java 应用程序，以监控 DynamoDB 的性能。应用程序将指标数据发送到您可以监控性能 CloudWatch 的地方。  
 有关如何设置和运行的完整源代码和说明，请参阅上的完整示例[GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/monitor_dynamodb)。  

**本示例中使用的服务**
+ CloudWatch
+ DynamoDB

------