# CloudWatch metrics published by canaries
<a name="CloudWatch_Synthetics_Canaries_metrics"></a>

Canaries publish the following metrics to CloudWatch in the `CloudWatchSynthetics` namespace. For more information about viewing CloudWatch metrics, see [View available metrics](viewing_metrics_with_cloudwatch.md) .

**Note**  
For multi-browser canaries, browser-dimension metrics are enabled by default to provide visibility into performance across browsers like Chrome, Firefox and other browsers. To disable browser metrics, set `browserDimension` to `false`.  
For single-browser canaries, browser-dimension metrics are disabled by default to avoid redundancy. To see metrics broken down by browser, set `browserDimension` to ` true`.


| Metric | Description | 
| --- | --- | 
|  `2xx`  | The number of network requests performed by the canary that returned OK responses, with response codes between 200 and 299.<br />This metric is reported for UI canaries that use runtime version ` syn-nodejs-2.0` or later, and is reported for API canaries that use runtime version `syn-nodejs-2.2` or later.<br />Valid Dimensions: CanaryName, Browser<br />Valid Statistic: Sum<br />Units: Count | 
|  `4xx`  | The number of network requests performed by the canary that returned Error responses, with response codes between 400 and 499.<br />This metric is reported for UI canaries that use runtime version ` syn-nodejs-2.0` or later, and is reported for API canaries that use runtime version `syn-nodejs-2.2` or later.<br />Valid Dimensions: CanaryName, Browser<br />Valid Statistic: Sum<br />Units: Count | 
|  `5xx`  | The number of network requests performed by the canary that returned Fault responses, with response codes between 500 and 599.<br />This metric is reported for UI canaries that use runtime version ` syn-nodejs-2.0` or later, and is reported for API canaries that use runtime version `syn-nodejs-2.2` or later.<br />Valid Dimensions: CanaryName, Browser<br />Valid Statistic: Sum<br />Units: Count | 
|  `Duration`  | The duration in milliseconds of the canary run.<br />Valid Dimensions: CanaryName, Browser, Location<br />Valid Statistic: Average<br />Units: Milliseconds | 
|  `DurationDryRun`  | The duration of DryRun executions. <br />Valid Dimensions: CanaryName, Browser<br />Valid Statistic: Average<br />Units: Milliseconds | 
|  `EphemeralStorageUsagePercent`  | The maximum percentage of ephemeral storage used compared to total ephemeral storage configured. This metric is collected at every 10 second interval. | 
|  `Failed`  | The number of canary runs that failed to execute. These failures are related to the canary itself.<br />Valid Dimensions: CanaryName, Browser<br />Valid Statistic: Sum<br />Units: Count | 
|  `Failed requests`  | The number of HTTP requests executed by the canary on the target website that failed with no response.<br />Valid Dimensions: CanaryName, Browser<br />Valid Statistic: Sum<br />Units: Count | 
|  `RetryCount`  | The number of times your canary retried. This metric is only displayed when there are retries.<br />Valid Dimensions: CanaryName, Browser<br />Valid Statistic: Sum<br />Units: Count | 
|  `SuccessPercent`  | The percentage of the runs of this canary that succeed and find no failures.<br />Valid Dimensions: CanaryName, Browser, Location<br />Valid Statistic: Average<br />Units: Percent | 
|  `SuccessPercentDryRun`  | The success percentage of DryRun executions.<br />Valid Dimensions: CanaryName, Browser<br />Valid Statistic: Average<br />Units: Percent | 
|  `SuccessPercentWithRetries`  | The percentage of the runs of this canary that succeed after all attempts.<br />Valid Dimensions: CanaryName, Browser, Location<br />Valid Statistic: Average<br />Units: Percent | 
|  `VisualMonitoringSuccessPercent`  | The percentage of visual comparisons that successfully matched the baseline screenshots during a canary run.<br />Valid Dimensions: CanaryName, Browser<br />Valid Statistic: Average<br />Units: Percent | 
|  `VisualMonitoringTotalComparisons`  | The total number of visual comparisons that happened during a canary run.<br />Valid Dimensions: CanaryName, Browser<br />Units: Count | 

**Note**  
Canaries that use either the `executeStep()` or `executeHttpStep()` methods from the Synthetics library also publish `SuccessPercent` and ` Duration` metrics with the dimensions `CanaryName` and `StepName` for each step.