# AlarmHistoryItem


Represents the history of a specific alarm.

## Contents


 ** AlarmContributorAttributes **   <a name="ACW-Type-AlarmHistoryItem-AlarmContributorAttributes"></a>
A map of attributes that describe the alarm contributor associated with this history item, providing context about the contributor's characteristics at the time of the event.  
Type: String to string map  
Map Entries: Maximum number of 30 items.  
Key Length Constraints: Minimum length of 1. Maximum length of 255.  
Value Length Constraints: Minimum length of 1. Maximum length of 1024.  
Required: No

 ** AlarmContributorId **   <a name="ACW-Type-AlarmHistoryItem-AlarmContributorId"></a>
The unique identifier of the alarm contributor associated with this history item, if applicable.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 16.  
Required: No

 ** AlarmName **   <a name="ACW-Type-AlarmHistoryItem-AlarmName"></a>
The descriptive name for the alarm.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 255.  
Required: No

 ** AlarmType **   <a name="ACW-Type-AlarmHistoryItem-AlarmType"></a>
The type of alarm, either metric alarm or composite alarm.  
Type: String  
Valid Values: `CompositeAlarm | MetricAlarm`   
Required: No

 ** HistoryData **   <a name="ACW-Type-AlarmHistoryItem-HistoryData"></a>
Data about the alarm, in JSON format.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 4095.  
Required: No

 ** HistoryItemType **   <a name="ACW-Type-AlarmHistoryItem-HistoryItemType"></a>
The type of alarm history item.  
Type: String  
Valid Values: `ConfigurationUpdate | StateUpdate | Action | AlarmContributorStateUpdate | AlarmContributorAction`   
Required: No

 ** HistorySummary **   <a name="ACW-Type-AlarmHistoryItem-HistorySummary"></a>
A summary of the alarm history, in text format.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 255.  
Required: No

 ** Timestamp **   <a name="ACW-Type-AlarmHistoryItem-Timestamp"></a>
The time stamp for the alarm history item.  
Type: Timestamp  
Required: No

## See Also


For more information about using this API in one of the language-specific Amazon SDKs, see the following:
+  [Amazon SDK for C\$1\$1](https://docs.amazonaws.cn/goto/SdkForCpp/monitoring-2010-08-01/AlarmHistoryItem) 
+  [Amazon SDK for Java V2](https://docs.amazonaws.cn/goto/SdkForJavaV2/monitoring-2010-08-01/AlarmHistoryItem) 
+  [Amazon SDK for Ruby V3](https://docs.amazonaws.cn/goto/SdkForRubyV3/monitoring-2010-08-01/AlarmHistoryItem)