AWS AmazonCloudWatch documentation change
Summary
Removed detailed section about alarm behavior for connected data sources, updated link references, and changed navigation titles
Security assessment
The changes involve removing operational details about CloudWatch alarm evaluation (including error handling and partial data scenarios), updating internal links, and modifying topic titles. There's no evidence of security vulnerability fixes or specific security enhancements. The removed content discussed general alarm behavior rather than addressing security flaws.
Diff
diff --git a/AmazonCloudWatch/latest/monitoring/Create_MultiSource_Alarm.md b/AmazonCloudWatch/latest/monitoring/Create_MultiSource_Alarm.md index bf3c692bf..24124355e 100644 --- a//AmazonCloudWatch/latest/monitoring/Create_MultiSource_Alarm.md +++ b//AmazonCloudWatch/latest/monitoring/Create_MultiSource_Alarm.md @@ -5,2 +4,0 @@ -Details about alarms for connected data sources - @@ -35 +33 @@ You can create alarms that watch metrics from data sources that aren't in CloudW -To create an M out of N alarm, specify a number for the first value that is lower than the number for the second value. For more information, see [Evaluating an alarm](./AlarmThatSendsEmail.html#alarm-evaluation). +To create an M out of N alarm, specify a number for the first value that is lower than the number for the second value. For more information, see [Alarm evaluation](./alarm-evaluation.html). @@ -37 +35 @@ To create an M out of N alarm, specify a number for the first value that is lowe - 12. For **Missing data treatment** , choose how the alarm behaves when some data points are missing. For more information, see [Configuring how CloudWatch alarms treat missing data](./AlarmThatSendsEmail.html#alarms-and-missing-data). + 12. For **Missing data treatment** , choose how the alarm behaves when some data points are missing. For more information, see [Configuring how CloudWatch alarms treat missing data](./alarms-and-missing-data.html). @@ -72,41 +69,0 @@ The alarm name must contain only UTF-8 characters. It can't contain ASCII contro -## Details about alarms for connected data sources - - * When CloudWatch evaluates an alarm, it does so every minute, even if the period for the alarm is longer than one minute. For the alarm to work, the Lambda function must be able to return a list of timestamps starting on any minute, not only on multiples of the period length. These timestamps must be spaced one period length apart. - -Therefore, if the data source queried by the Lambda can only return timestamps that are multiples of the period length, the function should "re-sample" the fetched data to match the timestamps expected by the `GetMetricData` request. - -For example, an alarm with a five-minute period is evaluated every minute using five-minute windows that shift by one minute each time. In this case: - - * For the alarm evaluation at 12:15:00, CloudWatch expects data points with timestamps of `12:00:00`, `12:05:00`, and `12:10:00`. - - * Then for the alarm evaluation at 12:16:00, CloudWatch expects data points with timestamps of `12:01:00`, `12:06:00`, and `12:11:00`. - - * When CloudWatch evaluates an alarm, any data points returned by the Lambda function that don't align with the expected timestamps are dropped, and the alarm is evaluated using the remaining expected data points. For example, when the alarm is evaluated at `12:15:00` it expects data with timestamps of `12:00:00`, `12:05:00`, and `12:10:00`. If it receives data with timestamps of `12:00:00`, `12:05:00`, `12:06:00`, and `12:10:00`, the data from `12:06:00` is dropped and CloudWatch evaluates the alarm using the other timestamps. - -Then for the next evaluation at `12:16:00`, it expects data with timestamps of `12:01:00`, `12:06:00`, and `12:11:00`. If it only has the data with timestamps of `12:00:00`, `12:05:00`, and `12:10:00`, all of these data points are ignored at 12:16:00 and the alarm transitions into the state according to how you specified the alarm to treat missing data. For more information, see [Evaluating an alarm](./AlarmThatSendsEmail.html#alarm-evaluation). - - * We recommend that you create these alarms to take actions when they transition to the `INSUFFICIENT_DATA` state, because several Lambda function failure use cases will transition the alarm to `INSUFFICIENT_DATA` regardless of the way that you set the alarm to treat missing data. - - * If the Lambda function returns an error: - - * If there is a permission problem with calling the Lambda function, the alarm begins having missing data transitions according to how you specified the alarm to treat missing data when you created it. - - * Any other error coming from the Lambda function causes the alarm to transition to `INSUFFICIENT_DATA`. - - * If the Lambda function returns partial data: - - * The alarm continues to be evaluated on the data points that are returned. - - * You can use the following methods to find whether an alarm on a Lambda function is currently evaluating its alarm state based on partial data: - - * In the console, choose an alarm and choose the **Details** page. If you see the message **Evaluation warning: Not evaluating all data appears on that page** , it is evaluating on partial data. - - * If you see the value `PARTIAL_DATA` in the `EvaluationState` field when you use the `describe-alarms` AWS CLI command or the DescribeAlarms API, it is evaluating on partial data. - - * An alarm also publishes events to Amazon EventBridge when it goes into the partial data state. - - * If the metric requested by the Lambda function has some delay so that the last data point is always missing, you should use a workaround. You can create an M out of N alarm or increase the evaluation period of the alarm. For more information about M out of N alarms, see [Evaluating an alarm](./AlarmThatSendsEmail.html#alarm-evaluation). - - - - @@ -119 +76 @@ To use the Amazon Web Services Documentation, Javascript must be enabled. Please -Create an alarm based on a Metrics Insights query +Create a multi time series alarm @@ -121 +78 @@ Create an alarm based on a Metrics Insights query -Create an alarm based on outlier detection +Alarming on logs