文件 AWS 開發套件範例 GitHub 儲存庫中有更多可用的 [AWS SDK 範例](https://github.com/awsdocs/aws-doc-sdk-examples)。

本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

# CloudWatch AWS SDKs的案例
<a name="cloudwatch_code_examples_scenarios"></a>

下列程式碼範例示範如何在 CloudWatch AWS SDKs中實作常見案例。這些案例向您展示如何透過呼叫 CloudWatch 中的多個函數或與其他 AWS 服務組合，完成特定任務。每個案例均包含完整原始碼的連結，您可在連結中找到如何設定和執行程式碼的相關指示。

案例的目標是獲得中等水平的經驗，協助您了解內容中的服務動作。

**Topics**
+ [開始使用警示](cloudwatch_example_cloudwatch_Scenario_GettingStarted_section.md)
+ [管理指標和警示](cloudwatch_example_cloudwatch_Usage_MetricsAlarms_section.md)
+ [監控 DynamoDB 效能](cloudwatch_example_cross_MonitorDynamoDB_section.md)

# 使用 AWS SDK 開始使用 CloudWatch 警示
<a name="cloudwatch_example_cloudwatch_Scenario_GettingStarted_section"></a>

以下程式碼範例顯示做法：
+ 建立警示。
+ 停用警示動作。
+ 描述警示。
+ 刪除警示。

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

**適用於 SAP ABAP 的開發套件**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/cwt#code-examples)中設定和執行。

```
    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.
```
+ 如需 API 詳細資訊，請參閱《*適用於 SAP ABAP 的AWS SDK API 參考*》中的下列主題。
  + [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 指標和警示
<a name="cloudwatch_example_cloudwatch_Usage_MetricsAlarms_section"></a>

以下程式碼範例顯示做法：
+ 建立警示以監看 CloudWatch 指標
+ 將資料放入指標並觸發警示。
+ 從警示中取得資料。
+ 刪除警示。

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

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/cloudwatch#code-examples)中設定和執行。
建立包裝 CloudWatch 操作的類別。  

```
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
```
使用包裝函式類別將資料放入指標中、觸發觀察指標的警示，以及從警示取得資料。  

```
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)
```
+ 如需 API 詳細資訊，請參閱《適用於 Python (Boto3) 的AWS SDK API 參考》**中的下列主題。
  + [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 AWS SDK 監控 Amazon DynamoDB 的效能
<a name="cloudwatch_example_cross_MonitorDynamoDB_section"></a>

下列程式碼範例示範如何設定應用程式使用 DynamoDB 來監控效能。

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

**適用於 Java 2.x 的 SDK**  
 此範例示範如何設定 Java 應用程式來監控 DynamoDB 的效能。應用程式會將指標資料傳送至 CloudWatch，您可以在其中監控效能。  
 如需完整的原始碼和如何設定及執行的指示，請參閱 [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/monitor_dynamodb) 上的完整範例。  

**此範例中使用的服務**
+ CloudWatch
+ DynamoDB

------