title: Route 53 health checks: CloudWatch didn't have enough data to determine the state of the alarm
body: <p>I have configured a health check in Route53 that monitors an alarm for API gateway.
  For some reason this health check doesn't change its status from healthy to unhealthy, even though the alarm is IN ALARM state. I set the alarm status using the AWS command: aws cloudwatch set-alarm-status.</p>
  <p>Here's the config for health check:</p>
  <pre><code>    &quot;HealthCheck&quot;: {
          &quot;Id&quot;: &quot;bxxx&quot;,
          &quot;CallerReference&quot;: &quot;xxxxx-xxx&quot;,
          &quot;HealthCheckConfig&quot;: {
              &quot;Type&quot;: &quot;CLOUDWATCH_METRIC&quot;,
              &quot;Inverted&quot;: false,
              &quot;Disabled&quot;: false,
              &quot;AlarmIdentifier&quot;: {
                  &quot;Region&quot;: &quot;us-east-1&quot;,
                  &quot;Name&quot;: &quot;APIGatewayAlarm&quot;
              },
              &quot;InsufficientDataHealthStatus&quot;: &quot;Healthy&quot;
          },
          &quot;HealthCheckVersion&quot;: 9,
          &quot;CloudWatchAlarmConfiguration&quot;: {
              &quot;EvaluationPeriods&quot;: 1,
              &quot;Threshold&quot;: 5.0,
              &quot;ComparisonOperator&quot;: &quot;GreaterThanOrEqualToThreshold&quot;,
              &quot;Period&quot;: 60,
              &quot;MetricName&quot;: &quot;5XXError&quot;,
              &quot;Namespace&quot;: &quot;AWS/ApiGateway&quot;,
              &quot;Statistic&quot;: &quot;Sum&quot;,
              &quot;Dimensions&quot;: [
                  {
                      &quot;Name&quot;: &quot;ApiName&quot;,
                      &quot;Value&quot;: &quot;An API GW&quot;
                  },
                  {
                      &quot;Name&quot;: &quot;Stage&quot;,
                      &quot;Value&quot;: &quot;v1&quot;
                  }
              ]
          }
      }
  }
  </code></pre>
  <p>Instead, what I see in the console under Health Checkers:</p>
  <p>Success: CloudWatch didn't have enough data to determine the state of the alarm. The Route 53 health checker considers the health check to be healthy based on the InsufficientDataHealthState setting.</p>
  <p>Any ideas of why is there insufficient data, if the Alarm is actually in the alarm state.</p>