# Dimension


The value to use in an Amazon CloudWatch custom metric dimension. This is used in the `PublishMetrics` [CustomAction](API_CustomAction.md). A CloudWatch custom metric dimension is a name/value pair that's part of the identity of a metric. 

 AWS Network Firewall sets the dimension name to `CustomAction` and you provide the dimension value. 

For more information about CloudWatch custom metric dimensions, see [Publishing Custom Metrics](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/publishingMetrics.html#usingDimensions) in the [Amazon CloudWatch User Guide](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/WhatIsCloudWatch.html).

## Contents


 ** Value **   <a name="networkfirewall-Type-Dimension-Value"></a>
The value to use in the custom metric dimension.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 128.  
Pattern: `^[a-zA-Z0-9-_ ]+$`   
Required: Yes

## See Also


For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/network-firewall-2020-11-12/Dimension) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/network-firewall-2020-11-12/Dimension) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/network-firewall-2020-11-12/Dimension)