2020/03/02 - Amazon CloudWatch - 1 new 2 updated api methods
Changes Introducing Amazon CloudWatch Composite Alarms
Creates or updates a composite alarm . When you create a composite alarm, you specify a rule expression for the alarm that takes into account the alarm states of other alarms that you have created. The composite alarm goes into ALARM state only if all conditions of the rule are met.
The alarms specified in a composite alarm's rule expression can include metric alarms and other composite alarms.
Using composite alarms can reduce alarm noise. You can create multiple metric alarms, and also create a composite alarm and set up alerts only for the composite alarm. For example, you could create a composite alarm that goes into ALARM state only when more than one of the underlying metric alarms are in ALARM state.
Currently, the only alarm actions that can be taken by composite alarms are notifying SNS topics.
Note
It is possible to create a loop or cycle of composite alarms, where composite alarm A depends on composite alarm B, and composite alarm B also depends on composite alarm A. In this scenario, you can't delete any composite alarm that is part of the cycle because there is always still a composite alarm that depends on that alarm that you want to delete.
To get out of such a situation, you must break the cycle by changing the rule of one of the composite alarms in the cycle to remove a dependency that creates the cycle. The simplest change to make to break a cycle is to change the AlarmRule of one of the alarms to False .
Additionally, the evaluation of composite alarms stops if CloudWatch detects a cycle in the evaluation path.
When this operation creates an alarm, the alarm state is immediately set to INSUFFICIENT_DATA . The alarm is then evaluated and its state is set appropriately. Any actions associated with the new state are then executed. For a composite alarm, this initial time after creation is the only time that the alarm can be in INSUFFICIENT_DATA state.
When you update an existing alarm, its state is left unchanged, but the update completely overwrites the previous configuration of the alarm.
See also: AWS API Documentation
Request Syntax
client.put_composite_alarm(
ActionsEnabled=True|False,
AlarmActions=[
'string',
],
AlarmDescription='string',
AlarmName='string',
AlarmRule='string',
InsufficientDataActions=[
'string',
],
OKActions=[
'string',
],
Tags=[
{
'Key': 'string',
'Value': 'string'
},
]
)
boolean
Indicates whether actions should be executed during any changes to the alarm state of the composite alarm. The default is TRUE .
list
The actions to execute when this alarm transitions to the ALARM state from any other state. Each action is specified as an Amazon Resource Name (ARN).
Valid Values: ``arn:aws:sns:region :account-id :sns-topic-name ``
(string) --
string
The description for the composite alarm.
string
[REQUIRED]
The name for the composite alarm. This name must be unique within your AWS account.
string
[REQUIRED]
An expression that specifies which other alarms are to be evaluated to determine this composite alarm's state. For each alarm that you reference, you designate a function that specifies whether that alarm needs to be in ALARM state, OK state, or INSUFFICIENT_DATA state. You can use operators (AND, OR and NOT) to combine multiple functions in a single expression. You can use parenthesis to logically group the functions in your expression.
You can use either alarm names or ARNs to reference the other alarms that are to be evaluated.
Functions can include the following:
ALARM("*alarm-name* or *alarm-ARN* ") is TRUE if the named alarm is in ALARM state.
OK("*alarm-name* or *alarm-ARN* ") is TRUE if the named alarm is in OK state.
INSUFFICIENT_DATA("*alarm-name* or *alarm-ARN* ") is TRUE if the named alarm is in INSUFFICIENT_DATA state.
TRUE always evaluates to TRUE.
FALSE always evaluates to FALSE.
TRUE and FALSE are useful for testing a complex AlarmRule structure, and for testing your alarm actions.
Alarm names specified in AlarmRule can be surrounded with double-quotes ("), but do not have to be.
The following are some examples of AlarmRule :
ALARM(CPUUtilizationTooHigh) AND ALARM(DiskReadOpsTooHigh) specifies that the composite alarm goes into ALARM state only if both CPUUtilizationTooHigh and DiskReadOpsTooHigh alarms are in ALARM state.
ALARM(CPUUtilizationTooHigh) AND NOT ALARM(DeploymentInProgress) specifies that the alarm goes to ALARM state if CPUUtilizationTooHigh is in ALARM state and DeploymentInProgress is not in ALARM state. This example reduces alarm noise during a known deployment window.
(ALARM(CPUUtilizationTooHigh) OR ALARM(DiskReadOpsTooHigh)) AND OK(NetworkOutTooHigh) goes into ALARM state if CPUUtilizationTooHigh OR DiskReadOpsTooHigh is in ALARM state, and if NetworkOutTooHigh is in OK state. This provides another example of using a composite alarm to prevent noise. This rule ensures that you are not notified with an alarm action on high CPU or disk usage if a known network problem is also occurring.
The AlarmRule can specify as many as 100 "children" alarms. The AlarmRule expression can have as many as 500 elements. Elements are child alarms, TRUE or FALSE statements, and parentheses.
list
The actions to execute when this alarm transitions to the INSUFFICIENT_DATA state from any other state. Each action is specified as an Amazon Resource Name (ARN).
Valid Values: ``arn:aws:sns:region :account-id :sns-topic-name ``
(string) --
list
The actions to execute when this alarm transitions to an OK state from any other state. Each action is specified as an Amazon Resource Name (ARN).
Valid Values: ``arn:aws:sns:region :account-id :sns-topic-name ``
(string) --
list
A list of key-value pairs to associate with the composite alarm. You can associate as many as 50 tags with an alarm.
Tags can help you organize and categorize your resources. You can also use them to scope user permissions, by granting a user permission to access or change only resources with certain tag values.
(dict) --
A key-value pair associated with a CloudWatch resource.
Key (string) -- [REQUIRED]
A string that you can use to assign a value. The combination of tag keys and values can help you organize and categorize your resources.
Value (string) -- [REQUIRED]
The value for the specified tag key.
None
{'AlarmTypes': ['CompositeAlarm | MetricAlarm'],
'ScanBy': 'TimestampDescending | TimestampAscending'}
Response {'AlarmHistoryItems': {'AlarmType': 'CompositeAlarm | MetricAlarm'}}
Retrieves the history for the specified alarm. You can filter the results by date range or item type. If an alarm name is not specified, the histories for either all metric alarms or all composite alarms are returned.
CloudWatch retains the history of an alarm even if you delete the alarm.
See also: AWS API Documentation
Request Syntax
client.describe_alarm_history(
AlarmName='string',
AlarmTypes=[
'CompositeAlarm'|'MetricAlarm',
],
HistoryItemType='ConfigurationUpdate'|'StateUpdate'|'Action',
StartDate=datetime(2015, 1, 1),
EndDate=datetime(2015, 1, 1),
MaxRecords=123,
NextToken='string',
ScanBy='TimestampDescending'|'TimestampAscending'
)
string
The name of the alarm.
list
Use this parameter to specify whether you want the operation to return metric alarms or composite alarms. If you omit this parameter, only metric alarms are returned.
(string) --
string
The type of alarm histories to retrieve.
datetime
The starting date to retrieve alarm history.
datetime
The ending date to retrieve alarm history.
integer
The maximum number of alarm history records to retrieve.
string
The token returned by a previous call to indicate that there is more data available.
string
Specified whether to return the newest or oldest alarm history first. Specify TimestampDescending to have the newest event history returned first, and specify TimestampAscending to have the oldest history returned first.
dict
Response Syntax
{
'AlarmHistoryItems': [
{
'AlarmName': 'string',
'AlarmType': 'CompositeAlarm'|'MetricAlarm',
'Timestamp': datetime(2015, 1, 1),
'HistoryItemType': 'ConfigurationUpdate'|'StateUpdate'|'Action',
'HistorySummary': 'string',
'HistoryData': 'string'
},
],
'NextToken': 'string'
}
Response Structure
(dict) --
AlarmHistoryItems (list) --
The alarm histories, in JSON format.
(dict) --
Represents the history of a specific alarm.
AlarmName (string) --
The descriptive name for the alarm.
AlarmType (string) --
The type of alarm, either metric alarm or composite alarm.
Timestamp (datetime) --
The time stamp for the alarm history item.
HistoryItemType (string) --
The type of alarm history item.
HistorySummary (string) --
A summary of the alarm history, in text format.
HistoryData (string) --
Data about the alarm, in JSON format.
NextToken (string) --
The token that marks the start of the next batch of returned results.
{'AlarmTypes': ['CompositeAlarm | MetricAlarm'],
'ChildrenOfAlarmName': 'string',
'ParentsOfAlarmName': 'string'}
Response {'CompositeAlarms': [{'ActionsEnabled': 'boolean',
'AlarmActions': ['string'],
'AlarmArn': 'string',
'AlarmConfigurationUpdatedTimestamp': 'timestamp',
'AlarmDescription': 'string',
'AlarmName': 'string',
'AlarmRule': 'string',
'InsufficientDataActions': ['string'],
'OKActions': ['string'],
'StateReason': 'string',
'StateReasonData': 'string',
'StateUpdatedTimestamp': 'timestamp',
'StateValue': 'OK | ALARM | INSUFFICIENT_DATA'}]}
Retrieves the specified alarms. You can filter the results by specifying a a prefix for the alarm name, the alarm state, or a prefix for any action.
See also: AWS API Documentation
Request Syntax
client.describe_alarms(
AlarmNames=[
'string',
],
AlarmNamePrefix='string',
AlarmTypes=[
'CompositeAlarm'|'MetricAlarm',
],
ChildrenOfAlarmName='string',
ParentsOfAlarmName='string',
StateValue='OK'|'ALARM'|'INSUFFICIENT_DATA',
ActionPrefix='string',
MaxRecords=123,
NextToken='string'
)
list
The names of the alarms to retrieve information about.
(string) --
string
An alarm name prefix. If you specify this parameter, you receive information about all alarms that have names that start with this prefix.
If this parameter is specified, you cannot specify AlarmNames .
list
Use this parameter to specify whether you want the operation to return metric alarms or composite alarms. If you omit this parameter, only metric alarms are returned.
(string) --
string
If you use this parameter and specify the name of a composite alarm, the operation returns information about the "children" alarms of the alarm you specify. These are the metric alarms and composite alarms referenced in the AlarmRule field of the composite alarm that you specify in ChildrenOfAlarmName . Information about the composite alarm that you name in ChildrenOfAlarmName is not returned.
If you specify ChildrenOfAlarmName , you cannot specify any other parameters in the request except for MaxRecords and NextToken . If you do so, you will receive a validation error.
Note
Only the Alarm Name , ARN , StateValue (OK/ALARM/INSUFFICIENT_DATA), and StateUpdatedTimestamp information are returned by this operation when you use this parameter. To get complete information about these alarms, perform another DescribeAlarms operation and specify the parent alarm names in the AlarmNames parameter.
string
If you use this parameter and specify the name of a metric or composite alarm, the operation returns information about the "parent" alarms of the alarm you specify. These are the composite alarms that have AlarmRule parameters that reference the alarm named in ParentsOfAlarmName . Information about the alarm that you specify in ParentsOfAlarmName is not returned.
If you specify ParentsOfAlarmName , you cannot specify any other parameters in the request except for MaxRecords and NextToken . If you do so, you will receive a validation error.
Note
Only the Alarm Name and ARN are returned by this operation when you use this parameter. To get complete information about these alarms, perform another DescribeAlarms operation and specify the parent alarm names in the AlarmNames parameter.
string
Specify this parameter to receive information only about alarms that are currently in the state that you specify.
string
Use this parameter to filter the results of the operation to only those alarms that use a certain alarm action. For example, you could specify the ARN of an SNS topic to find all alarms that send notifications to that topic.
integer
The maximum number of alarm descriptions to retrieve.
string
The token returned by a previous call to indicate that there is more data available.
dict
Response Syntax
{
'CompositeAlarms': [
{
'ActionsEnabled': True|False,
'AlarmActions': [
'string',
],
'AlarmArn': 'string',
'AlarmConfigurationUpdatedTimestamp': datetime(2015, 1, 1),
'AlarmDescription': 'string',
'AlarmName': 'string',
'AlarmRule': 'string',
'InsufficientDataActions': [
'string',
],
'OKActions': [
'string',
],
'StateReason': 'string',
'StateReasonData': 'string',
'StateUpdatedTimestamp': datetime(2015, 1, 1),
'StateValue': 'OK'|'ALARM'|'INSUFFICIENT_DATA'
},
],
'MetricAlarms': [
{
'AlarmName': 'string',
'AlarmArn': 'string',
'AlarmDescription': 'string',
'AlarmConfigurationUpdatedTimestamp': datetime(2015, 1, 1),
'ActionsEnabled': True|False,
'OKActions': [
'string',
],
'AlarmActions': [
'string',
],
'InsufficientDataActions': [
'string',
],
'StateValue': 'OK'|'ALARM'|'INSUFFICIENT_DATA',
'StateReason': 'string',
'StateReasonData': 'string',
'StateUpdatedTimestamp': datetime(2015, 1, 1),
'MetricName': 'string',
'Namespace': 'string',
'Statistic': 'SampleCount'|'Average'|'Sum'|'Minimum'|'Maximum',
'ExtendedStatistic': 'string',
'Dimensions': [
{
'Name': 'string',
'Value': 'string'
},
],
'Period': 123,
'Unit': 'Seconds'|'Microseconds'|'Milliseconds'|'Bytes'|'Kilobytes'|'Megabytes'|'Gigabytes'|'Terabytes'|'Bits'|'Kilobits'|'Megabits'|'Gigabits'|'Terabits'|'Percent'|'Count'|'Bytes/Second'|'Kilobytes/Second'|'Megabytes/Second'|'Gigabytes/Second'|'Terabytes/Second'|'Bits/Second'|'Kilobits/Second'|'Megabits/Second'|'Gigabits/Second'|'Terabits/Second'|'Count/Second'|'None',
'EvaluationPeriods': 123,
'DatapointsToAlarm': 123,
'Threshold': 123.0,
'ComparisonOperator': 'GreaterThanOrEqualToThreshold'|'GreaterThanThreshold'|'LessThanThreshold'|'LessThanOrEqualToThreshold'|'LessThanLowerOrGreaterThanUpperThreshold'|'LessThanLowerThreshold'|'GreaterThanUpperThreshold',
'TreatMissingData': 'string',
'EvaluateLowSampleCountPercentile': 'string',
'Metrics': [
{
'Id': 'string',
'MetricStat': {
'Metric': {
'Namespace': 'string',
'MetricName': 'string',
'Dimensions': [
{
'Name': 'string',
'Value': 'string'
},
]
},
'Period': 123,
'Stat': 'string',
'Unit': 'Seconds'|'Microseconds'|'Milliseconds'|'Bytes'|'Kilobytes'|'Megabytes'|'Gigabytes'|'Terabytes'|'Bits'|'Kilobits'|'Megabits'|'Gigabits'|'Terabits'|'Percent'|'Count'|'Bytes/Second'|'Kilobytes/Second'|'Megabytes/Second'|'Gigabytes/Second'|'Terabytes/Second'|'Bits/Second'|'Kilobits/Second'|'Megabits/Second'|'Gigabits/Second'|'Terabits/Second'|'Count/Second'|'None'
},
'Expression': 'string',
'Label': 'string',
'ReturnData': True|False,
'Period': 123
},
],
'ThresholdMetricId': 'string'
},
],
'NextToken': 'string'
}
Response Structure
(dict) --
CompositeAlarms (list) --
The information about any composite alarms returned by the operation.
(dict) --
The details about a composite alarm.
ActionsEnabled (boolean) --
Indicates whether actions should be executed during any changes to the alarm state.
AlarmActions (list) --
The actions to execute when this alarm transitions to the ALARM state from any other state. Each action is specified as an Amazon Resource Name (ARN).
(string) --
AlarmArn (string) --
The Amazon Resource Name (ARN) of the alarm.
AlarmConfigurationUpdatedTimestamp (datetime) --
The time stamp of the last update to the alarm configuration.
AlarmDescription (string) --
The description of the alarm.
AlarmName (string) --
The name of the alarm.
AlarmRule (string) --
The rule that this alarm uses to evaluate its alarm state.
InsufficientDataActions (list) --
The actions to execute when this alarm transitions to the INSUFFICIENT_DATA state from any other state. Each action is specified as an Amazon Resource Name (ARN).
(string) --
OKActions (list) --
The actions to execute when this alarm transitions to the OK state from any other state. Each action is specified as an Amazon Resource Name (ARN).
(string) --
StateReason (string) --
An explanation for the alarm state, in text format.
StateReasonData (string) --
An explanation for the alarm state, in JSON format.
StateUpdatedTimestamp (datetime) --
The time stamp of the last update to the alarm state.
StateValue (string) --
The state value for the alarm.
MetricAlarms (list) --
The information about any metric alarms returned by the operation.
(dict) --
The details about a metric alarm.
AlarmName (string) --
The name of the alarm.
AlarmArn (string) --
The Amazon Resource Name (ARN) of the alarm.
AlarmDescription (string) --
The description of the alarm.
AlarmConfigurationUpdatedTimestamp (datetime) --
The time stamp of the last update to the alarm configuration.
ActionsEnabled (boolean) --
Indicates whether actions should be executed during any changes to the alarm state.
OKActions (list) --
The actions to execute when this alarm transitions to the OK state from any other state. Each action is specified as an Amazon Resource Name (ARN).
(string) --
AlarmActions (list) --
The actions to execute when this alarm transitions to the ALARM state from any other state. Each action is specified as an Amazon Resource Name (ARN).
(string) --
InsufficientDataActions (list) --
The actions to execute when this alarm transitions to the INSUFFICIENT_DATA state from any other state. Each action is specified as an Amazon Resource Name (ARN).
(string) --
StateValue (string) --
The state value for the alarm.
StateReason (string) --
An explanation for the alarm state, in text format.
StateReasonData (string) --
An explanation for the alarm state, in JSON format.
StateUpdatedTimestamp (datetime) --
The time stamp of the last update to the alarm state.
MetricName (string) --
The name of the metric associated with the alarm, if this is an alarm based on a single metric.
Namespace (string) --
The namespace of the metric associated with the alarm.
Statistic (string) --
The statistic for the metric associated with the alarm, other than percentile. For percentile statistics, use ExtendedStatistic .
ExtendedStatistic (string) --
The percentile statistic for the metric associated with the alarm. Specify a value between p0.0 and p100.
Dimensions (list) --
The dimensions for the metric associated with the alarm.
(dict) --
Expands the identity of a metric.
Name (string) --
The name of the dimension.
Value (string) --
The value representing the dimension measurement.
Period (integer) --
The period, in seconds, over which the statistic is applied.
Unit (string) --
The unit of the metric associated with the alarm.
EvaluationPeriods (integer) --
The number of periods over which data is compared to the specified threshold.
DatapointsToAlarm (integer) --
The number of data points that must be breaching to trigger the alarm.
Threshold (float) --
The value to compare with the specified statistic.
ComparisonOperator (string) --
The arithmetic operation to use when comparing the specified statistic and threshold. The specified statistic value is used as the first operand.
TreatMissingData (string) --
Sets how this alarm is to handle missing data points. If this parameter is omitted, the default behavior of missing is used.
EvaluateLowSampleCountPercentile (string) --
Used only for alarms based on percentiles. If ignore , the alarm state does not change during periods with too few data points to be statistically significant. If evaluate or this parameter is not used, the alarm is always evaluated and possibly changes state no matter how many data points are available.
Metrics (list) --
An array of MetricDataQuery structures, used in an alarm based on a metric math expression. Each structure either retrieves a metric or performs a math expression. One item in the Metrics array is the math expression that the alarm watches. This expression by designated by having ReturnValue set to true.
(dict) --
This structure is used in both GetMetricData and PutMetricAlarm . The supported use of this structure is different for those two operations.
When used in GetMetricData , it indicates the metric data to return, and whether this call is just retrieving a batch set of data for one metric, or is performing a math expression on metric data. A single GetMetricData call can include up to 500 MetricDataQuery structures.
When used in PutMetricAlarm , it enables you to create an alarm based on a metric math expression. Each MetricDataQuery in the array specifies either a metric to retrieve, or a math expression to be performed on retrieved metrics. A single PutMetricAlarm call can include up to 20 MetricDataQuery structures in the array. The 20 structures can include as many as 10 structures that contain a MetricStat parameter to retrieve a metric, and as many as 10 structures that contain the Expression parameter to perform a math expression. Of those Expression structures, one must have True as the value for ReturnData . The result of this expression is the value the alarm watches.
Any expression used in a PutMetricAlarm operation must return a single time series. For more information, see Metric Math Syntax and Functions in the Amazon CloudWatch User Guide .
Some of the parameters of this structure also have different uses whether you are using this structure in a GetMetricData operation or a PutMetricAlarm operation. These differences are explained in the following parameter list.
Id (string) --
A short name used to tie this object to the results in the response. This name must be unique within a single call to GetMetricData . If you are performing math expressions on this set of data, this name represents that data and can serve as a variable in the mathematical expression. The valid characters are letters, numbers, and underscore. The first character must be a lowercase letter.
MetricStat (dict) --
The metric to be returned, along with statistics, period, and units. Use this parameter only if this object is retrieving a metric and not performing a math expression on returned data.
Within one MetricDataQuery object, you must specify either Expression or MetricStat but not both.
Metric (dict) --
The metric to return, including the metric name, namespace, and dimensions.
Namespace (string) --
The namespace of the metric.
MetricName (string) --
The name of the metric. This is a required field.
Dimensions (list) --
The dimensions for the metric.
(dict) --
Expands the identity of a metric.
Name (string) --
The name of the dimension.
Value (string) --
The value representing the dimension measurement.
Period (integer) --
The granularity, in seconds, of the returned data points. For metrics with regular resolution, a period can be as short as one minute (60 seconds) and must be a multiple of 60. For high-resolution metrics that are collected at intervals of less than one minute, the period can be 1, 5, 10, 30, 60, or any multiple of 60. High-resolution metrics are those metrics stored by a PutMetricData call that includes a StorageResolution of 1 second.
If the StartTime parameter specifies a time stamp that is greater than 3 hours ago, you must specify the period as follows or no data points in that time range is returned:
Start time between 3 hours and 15 days ago - Use a multiple of 60 seconds (1 minute).
Start time between 15 and 63 days ago - Use a multiple of 300 seconds (5 minutes).
Start time greater than 63 days ago - Use a multiple of 3600 seconds (1 hour).
Stat (string) --
The statistic to return. It can include any CloudWatch statistic or extended statistic.
Unit (string) --
When you are using a Put operation, this defines what unit you want to use when storing the metric.
In a Get operation, if you omit Unit then all data that was collected with any unit is returned, along with the corresponding units that were specified when the data was reported to CloudWatch. If you specify a unit, the operation returns only data data that was collected with that unit specified. If you specify a unit that does not match the data collected, the results of the operation are null. CloudWatch does not perform unit conversions.
Expression (string) --
The math expression to be performed on the returned data, if this object is performing a math expression. This expression can use the Id of the other metrics to refer to those metrics, and can also use the Id of other expressions to use the result of those expressions. For more information about metric math expressions, see Metric Math Syntax and Functions in the Amazon CloudWatch User Guide .
Within each MetricDataQuery object, you must specify either Expression or MetricStat but not both.
Label (string) --
A human-readable label for this metric or expression. This is especially useful if this is an expression, so that you know what the value represents. If the metric or expression is shown in a CloudWatch dashboard widget, the label is shown. If Label is omitted, CloudWatch generates a default.
ReturnData (boolean) --
When used in GetMetricData , this option indicates whether to return the timestamps and raw data values of this metric. If you are performing this call just to do math expressions and do not also need the raw data returned, you can specify False . If you omit this, the default of True is used.
When used in PutMetricAlarm , specify True for the one expression result to use as the alarm. For all other metrics and expressions in the same PutMetricAlarm operation, specify ReturnData as False.
Period (integer) --
The granularity, in seconds, of the returned data points. For metrics with regular resolution, a period can be as short as one minute (60 seconds) and must be a multiple of 60. For high-resolution metrics that are collected at intervals of less than one minute, the period can be 1, 5, 10, 30, 60, or any multiple of 60. High-resolution metrics are those metrics stored by a PutMetricData operation that includes a StorageResolution of 1 second .
ThresholdMetricId (string) --
In an alarm based on an anomaly detection model, this is the ID of the ANOMALY_DETECTION_BAND function used as the threshold for the alarm.
NextToken (string) --
The token that marks the start of the next batch of returned results.